Watering, how media, pot size/shape and environment affect it

[GDub51]

Excellent subject. One of the reasons I've gone to using coco in my cloth air pots, I've also started to regulate things like temp, humidity and air movement in the room, much more closely. I've also take many of these steps to eliminate the problems of over/under water.

Do you think that adding amendments to coco, such as possibly some perlite, or even possibly larger pieces like bark, might create some small spaces within the media that could be of benefit of increasing oxygen exchange? Would numerous amounts of tiny empty voids in the medium allow better root proliferation? Or is coco pretty much as optimized as it possibly can be. Or maybe even regulating the media structure from the bottom upwards to the top point, creating a slightly different mixture content in an ascending direction, to help optimize better oxygen transfer in all parts of the media.

There's so much about this subject in particular to explore new and novel ways of increasing/optimizing gas exchange in the media, it's a very critical factor, no doubt.

Coco is the one thing I have not tried to create a better gas exchange. My perlite/pumice/cactus & succulent soil/sand portion of my mix is up to almost half of the total volume. Yet I still cannot get my soil to drain properly or provide space for root expansion. My root balls are severely stunted making the plants difficult to water and unsteady in the Santa Ana winds even with silica supplementation. I had thought leftover hyphae from mycorrhizae supplementation from previous grows, after being raked in the sun for a week to kill any pathogens that had wiped out my first grow this year. So for my fourth try this season, now with an auto (Bruce Banner Fast) none of the leftover soil was used. I used fresh Ocean Forest and compost with a 40% mix of the above noted "circulation additives" and still have a pot of wet mud that can't breathe. This mix is touted all over as correct, so why doesn't it work for me? My pots are 21" tall!! I also have used a plant stake to poke 30+-holes to the bottom of my tall plastic cans (see pics) for drainage and circulation to no effect. I have now gone thru 56! seeds this year to get a half dozen runted waste of times. I've used the same mixes for previous seasons with fine success, I'm still at a total loss as to why I can't grow this year due to soil problems not draining. Yes, it is a little cooler this year, but not enough to make this much trouble. I cannot repot again as I now have a broken shoulder. I'm going away for a week so plants may die anyway as I have no one to help water. I bought an automatic watering system only to realize it only uses tap water which here is poison to young seedlings with a PPM over 500!! And it's full of chlorine and chloramines. I may try another auto when I return, I'll no doubt have some empty cans by then as the plants die off.

 

[Tracyfri]

Ever thought about hydro? about dwc? or top drip or ebb and flow with clay pebbles? No more soil. It doesn't need to be complicated the hydro that is. Just curious. I know what frustration of the nature you describe feels like. It's no joke. Hope your doing better

 

[Aqua Man]

Ever thought about hydro? about dwc? or top drip or ebb and flow with clay pebbles? No more soil. It doesn't need to be complicated the hydro that is. Just curious. I know what frustration of the nature you describe feels like. It's no joke. Hope your doing better

Yeah I started in hydro. Growth was kinda stupid. Coco works for me because if the ability to SoG and move plants around.

 

[Tracyfri]

Lol!! I was referring to the op with all the soul issues

 

[Texasdigger35]

TEMPERATURE AND HUMIDITY

The warmer the temps the more evaporation occurs.

The lower your humidity the more evaporation occurs

The more surface area exposed to air movement (wind) the more evaporation.

Think those don't need an explanation. But the difference in pot material coupled with these environmental factors will have an impact on your watering needs.

The temperature of the media not only affects evaporation but also directly affect the temperature of the plant and leaf temps. This has a large impact on nutrient uptake and transportation.

First let me say that this next part is opinion and I will gives my reasoning for my opinions. With the exception of hydro (leaving this part out as this post is about watering not hydro) roots like to be about the same temperature as the leaves contrary to what's talked about from many prominent growers in the industry but not all like Mr.Bruce Bugbee. IMO ideal root temps are the same as ideal leaf temps and overall plant temps especially since the root temps have a large impact on the plant and leaf temps. What are ideal temps imo and many studies show that leaf temps (NOT AIR TEMPS) of around 77f are most efficient. So how does a cool rootzone impact the plants negatively? Well it's 2 fold because of the cool temps the viscosity (measument of flow rate) of the sap will decrease so its harder for the plant to move the nutrients through the plant. The other is absorption and one fact is that in a cooler rootzone the concentration of nutrients is higher (but aqua you just said it slows absorption) well it does as the nutrients build up in the roots it can absorb less and this has a direct impact negatively on the plant. It may appear to be overwatered because the plant is now struggling to take up and use oxygen. Add that to the slowed transpiration rates and you have the same symtom many refer to overwatering which againnos lack of o2. Now take a cold rootzone where the plants slow water uptake and then add the saturation zone to it and you can see the road to correction and recover is a long one and can have huge impact on growth and yields.

So you your pots up off the floor

Super good info here. Would you care to expand on the hot temp aspect? Went over pretty well what cold temps do but not hot. This year were in the mid 90s daily and its a cool year. 100s are normal most years with very high humidity.

 

[Texasdigger35]

Coco is the one thing I have not tried to create a better gas exchange. My perlite/pumice/cactus & succulent soil/sand portion of my mix is up to almost half of the total volume. Yet I still cannot get my soil to drain properly or provide space for root expansion. My root balls are severely stunted making the plants difficult to water and unsteady in the Santa Ana winds even with silica supplementation. I had thought leftover hyphae from mycorrhizae supplementation from previous grows, after being raked in the sun for a week to kill any pathogens that had wiped out my first grow this year. So for my fourth try this season, now with an auto (Bruce Banner Fast) none of the leftover soil was used. I used fresh Ocean Forest and compost with a 40% mix of the above noted "circulation additives" and still have a pot of wet mud that can't breathe. This mix is touted all over as correct, so why doesn't it work for me? My pots are 21" tall!! I also have used a plant stake to poke 30+-holes to the bottom of my tall plastic cans (see pics) for drainage and circulation to no effect. I have now gone thru 56! seeds this year to get a half dozen runted waste of times. I've used the same mixes for previous seasons with fine success, I'm still at a total loss as to why I can't grow this year due to soil problems not draining. Yes, it is a little cooler this year, but not enough to make this much trouble. I cannot repot again as I now have a broken shoulder. I'm going away for a week so plants may die anyway as I have no one to help water. I bought an automatic watering system only to realize it only uses tap water which here is poison to young seedlings with a PPM over 500!! And it's full of chlorine and chloramines. I may try another auto when I return, I'll no doubt have some empty cans by then as the plants die off.

Maybe you should start ur own thread. I've got some ideas about what's wrong but don't want to interfere with aquamans awesome info. It was a really good thread he had going.

 

[Tracyfri]

Lol!! I was referring to the op with all the soul issues

SOIL issues I meant.

 

[Aqua Man]

Super good info here. Would you care to expand on the hot temp aspect? Went over pretty well what cold temps do but not hot. This year were in the mid 90s daily and its a cool year. 100s are normal most years with very high humidity.

Good point I'll respond fast off the top of my head then add info to the main post once I can confirm and grab a little more from some reading so thus won't be as thorough but just some of the info as I understand it based how plants work.

So outdoors high temos plants can tolerate much better because those temps are not constant but rather peak, the air movement is really good and the soil generally stays fairly cool. Now in pots that changes.

Like most things plants they like stability so they have adapted to help them maintain a plant temperature that they prefer. Many studies show cannabis around 75-77f is what they do the highest photosynthetic rates.

So in soil you see much less heat stress than you would say in a clone beside it in a pot.

Thus us because ground temp impacts the temp of the water being taken up and this provides some cooling.

The wind causes forced evaporation from the leaves cooling the plant much like when we sweat. Transpiration will increase in higher temps in attempt to help keep the plants cool also.

Thus leads to a lot more uptake and you should be mindful to reduce your nutrients accordingly.

Hi temls cause more evaporation from media which can help keep it cool and why fabric posts stay cool than plastic pots.

I can go on here but I'll add to the main post and then post that it's updated

 

[Frankster]

Precisely why I cut cal supplements back 50% after stretch and stop all together after swelling.

I dont think K is reduced so much due to transpiration but it's not something I'm confident to say absolutely.

Many nutrients limit uptake of K. P and N also do. IMO P should be fed in veg and early flower more so than mid to late for partially the same reason. N is the same. But ratios are taken to far in general imo and a transition ratio should be fed through flower with N, P and Ca being reduced after stretch and cut as much as possible after swelling.

Just my opinion.

So are you saying K should be the frontrunner in driving the finish? Can I extrapolate that from all of what you just said aqua?

 

[Frankster]

I'm trying the drain test on raw left over raked over soil. I can't even get the soil in the cup to saturate. It's so dense its just running off the side. I've reduced the water to a dribble but after 20 min. the soil is still not saturated. Obviously too dense. Next I'll try mix three, my last attempt it should at least be good for the test. I'm assuming group one fails in that it would not even saturate evenly. Group three is still filling with a dribble. At ten minutes there are still air pockets on the side. After about 20 min. of filling mix 3 is now "saturated". I'm letting it sit with the other plants to check this evening. Unfortunately, 90% of the mass of soil I have is the old "dusty stuff". I don't even know what I would do if I had to dump all of it. However, it seems my raking to detoxify the stuff along with all the recharge mixing has ruined it. I wish I knew. I'll be back with the results of the water saturation test.

The key here is slow, I add a cup of nutrients at a time when things get really tight, go out for puffs, come back. Dense root balls take time, but there worth it IMO, up to a point anyhow. Also, if things get too tight, I use a surfactant, such as yukka extract to wash out and cleanse the root zone. I do that routinely about once weekly all though flowering.

 

[Frankster]

Coco is the one thing I have not tried to create a better gas exchange. My perlite/pumice/cactus & succulent soil/sand portion of my mix is up to almost half of the total volume. Yet I still cannot get my soil to drain properly or provide space for root expansion. My root balls are severely stunted making the plants difficult to water and unsteady in the Santa Ana winds even with silica supplementation. I had thought leftover hyphae from mycorrhizae supplementation from previous grows, after being raked in the sun for a week to kill any pathogens that had wiped out my first grow this year. So for my fourth try this season, now with an auto (Bruce Banner Fast) none of the leftover soil was used. I used fresh Ocean Forest and compost with a 40% mix of the above noted "circulation additives" and still have a pot of wet mud that can't breathe. This mix is touted all over as correct, so why doesn't it work for me? My pots are 21" tall!! I also have used a plant stake to poke 30+-holes to the bottom of my tall plastic cans (see pics) for drainage and circulation to no effect. I have now gone thru 56! seeds this year to get a half dozen runted waste of times. I've used the same mixes for previous seasons with fine success, I'm still at a total loss as to why I can't grow this year due to soil problems not draining. Yes, it is a little cooler this year, but not enough to make this much trouble. I cannot repot again as I now have a broken shoulder. I'm going away for a week so plants may die anyway as I have no one to help water. I bought an automatic watering system only to realize it only uses tap water which here is poison to young seedlings with a PPM over 500!! And it's full of chlorine and chloramines. I may try another auto when I return, I'll no doubt have some empty cans by then as the plants die off.

Sounds almost like an excessive nutrient issue perhaps, or probably something in the water like you say. Carbonate or lime buildup can be a real issue, no doubt. My guess if the starting water ppm is that high, you've got carbonate issues, so let the water sit in 5 gallon vessels for a day or two allow settlement of your particulate matter, then scoop out, always discarding the bottom portions.

Either that, or get a good filter. Knocking on wood for the blessing of abundant pristine clean water sources; here at the foot of the cascades.

 

[Frankster]

Good point I'll respond fast off the top of my head then add info to the main post once I can confirm and grab a little more from some reading so thus won't be as thorough but just some of the info as I understand it based how plants work.

So outdoors high temos plants can tolerate much better because those temps are not constant but rather peak, the air movement is really good and the soil generally stays fairly cool. Now in pots that changes.

Like most things plants they like stability so they have adapted to help them maintain a plant temperature that they prefer. Many studies show cannabis around 75-77f is what they do the highest photosynthetic rates.

So in soil you see much less heat stress than you would say in a clone beside it in a pot.

Thus us because ground temp impacts the temp of the water being taken up and this provides some cooling.

The wind causes forced evaporation from the leaves cooling the plant much like when we sweat. Transpiration will increase in higher temps in attempt to help keep the plants cool also.

Thus leads to a lot more uptake and you should be mindful to reduce your nutrients accordingly.

Hi temls cause more evaporation from media which can help keep it cool and why fabric posts stay cool than plastic pots.

I can go on here but I'll add to the main post and then post that it's updated

Agreed, that's why hot arid locations should almost always bury plants, if possible. I seen a grow, looked like Arizona, or So. Cali on the outdoor thread awhile back. Guy bulldozed a 4 foot trench in the desert, then put his plants in the hole, allowing those precious root zones even cooler protection a good 8-10 feet below the top soil line, ensuring the plants would keep sufficiently cool. His plants looked fantastic, and I suspect this is a technique developed locally, though trial and errors.

It also has the added benefit of being more stealth, and requiring less watering.

 

[PipeCarver]

Ok lots of posts on how to water plants. So I thought I would put together a thread on how different factors contribute to different results that ppl see. This is again not my work so don't go giving me credit although I will add some to it.

This will be a long read based on my personal knowledge, opinions, research and others work to consolidate information for our members. I'm not presenting my opinions as facts so take from this what you like. I will be putting it in subsection format for easy reference.

First I want to make an important point to take into consideration before reading. The tap root will grow directly downwards to the bottom of the container before spreading out.

PERCHED WATER TABLE

What is it?

The perched water table is basically the height of the saturation zone where capillary action and gravity cancel eachother out. This area will be saturated with water and will be responsible most growers issues with watering practices especially in soil grows.

WHAT IS CAPILLARY ACTION

CAPILLARY action is is the combination of the cohesive and adhesive properties of water.

In short adhesion is water clinging to the media (think of it like wicking or soaking up)

Cohesion is where the water clings to itself.

So as the water is wicked up (adhesion) it pulls more water with it through Cohesion and at the point gravity and these properties cancel eachother out is the perched water table.

This perched water table will always remain the SAME HEIGHT and will always stay saturated unless taken up by the plants or evaporates when the pot dries out. No matter the container height, depth or volume of media. So if a tall skinny container had a perched water table of 1" then a short wide one of the same media will also have a perched water table of 1". Which means the ratio of water to air in a wide pot will be higher than a tall skinny pot which will have a higher air to water ratio... keep this in mind as we get further.

Different media's have different perched water tables. A more absorbent media will have a higher perched water table than a less absorbent media... REMEMBER THIS as it makes a big difference on pot selection for your media.

DIFFERENT MEDIA

Water holding capacity is directly related to the height of the perched water table so soils with more clay or silt and less sand will have a higher perched water table than those with more sand because sand is a larger particle.

The larger the overall particles of the media the lower the perched water table and better the drainage.

By adding things like perlite or vermiculite (while vermiculite is good at absorbing water it also improves drainage so its helpful in keeping a more even level of moisture throught the media while increasing drainage due to its size) we can lower the perched water table by reducing the wicking (adhesion) ability and creating more space between particles overall reducing the cohesion effect and inturn the height of the perched water table.

Media's like peat based or coco have a much higher drainage and lower perched water table than soil and are therefore less susceptible to over watering but will require more frequent watering due to the lower water holding capacity.

Adding thing like perlite or hydroton to the bottom of the pots will NOT reduce the water table but instead raise it. This is because as I said the height of the water table will not change for a given media. So if you add things like that to the bottom you are essentially just moving the water table up.

Basically the larger the particles IN the media the better drainage and lower the water table.

If you want to see the height of your perched water table use a clear cup with drain holes fill with media and saturate it. Wait a few hrs for drainage and then come back and look. You can see the difference in the varying media's if you want to experiment.

POT SIZE

I have already covered this a bit but my opinion is if you are using a media with a higher water table you will benefit from taller narrower pots and if using a media with a lower perched water table the shorter wider ones may benefit you depending on your watering practices.

I prefer the taller over wider no matter the media as I choose to water often and have a higher air holding capacity and lower water table but that can work against you if you can't water as frequently and as plants grow it can greatly increase the frequency required as the roots will be pulling the water out of that saturation zone quickly. So you may want to use taller pots for small plants and transplant into a wider one as they grow.

You also don't want a pot that's to tall and the top portion of the media is drying out to fast while the bottom is wet.

Let's use seedlings as an example take a solo cup or a large container... the water table will be the same height in either. I see sooo often ppl trying to water a tiny bit in circles or mist the surface and for lack of other words IT DEIVES ME NUTS. Why because the roots are so shallow they are not at risk of being over watered. Remember though tap roots grow straight down so we to be mindful as they grow depending on the gas exchange of the media that the majority of roots are not sitting in the saturated zone with poor gas exchange because this will cause lack of oxygen that we incorrectly refer to as overwatering which is actually the cause not the symptom.

It's important to fill containers to the top to give us a good amount of space above the perched water table that high in o2. If you fill a solo cup halfway with soil it's likely to be sitting in the saturation zone and will not do well.


Also going to make the point that plants will be most susceptible to overwatering when the roots first hit the bottom and spread out until they fill the bottom and start moving back up out of the saturation zone. So again it may be more beneficial to use a taller narrow pot for the early stages of growth (2-4 weekss depending on growth) and transplant into a wider pot as you go. After the transplant almost all of the roots will be above the saturation zone and it become much harder to over water. New roots will again work their way down into the saturation zone but you will have plenty above so its less likely to over water and why uppotting as you go I see as a benefit instead of starting in a large wide container.

POT MATERIAL

Some prefer plastic others fabric, air pots etc.

This can affect the perched water table by evaporation as the lager the exposed surface area the more evaporation that occurs from the media in say fabric pots. This imo has a few benefits.... slightly reducing the perched water table but more so the exposure for gas exchange that's happening and that's a good thing for o2 levels in the root zone that I feel are directly related to growth rates and I'll explain why going a bit off topic for a second.

It's no coincidence that the fastest growing media's have the highest amounts of o2 and gas exchange.... for eg aeroponics have unlimited to rich o2 and water. Hydro similar with slightly less o2, soiless media's such as coco and I would possible include peat and last soil. If you notice they are in order of growth rates and its not hard to see the difference in thier air holding capacity in that order. And the fact that larger particles also have a better gas exchange rate. This is important because the plants take in oxygen and expell co2 in the rootzone as do the microbes on top of that so good gas exchange is important for both.

Just a note... air pruning has nothing to do with the benefits of fabric pots all it does is signal the roots to grow in a different direction.

But let's get back on topic of watering and how it's affected.

TEMPERATURE AND HUMIDITY

The warmer the temps the more evaporation occurs.

The lower your humidity the more evaporation occurs

The more surface area exposed to air movement (wind) the more evaporation.

Think those don't need an explanation. But the difference in pot material coupled with these environmental factors will have an impact on your watering needs.

The temperature of the media not only affects evaporation but also directly affect the temperature of the plant and leaf temps. This has a large impact on nutrient uptake and transportation.

First let me say that this next part is opinion and I will gives my reasoning for my opinions. With the exception of hydro (leaving this part out as this post is about watering not hydro) roots like to be about the same temperature as the leaves contrary to what's talked about from many prominent growers in the industry but not all like Mr.Bruce Bugbee. IMO ideal root temps are the same as ideal leaf temps and overall plant temps especially since the root temps have a large impact on the plant and leaf temps. What are ideal temps imo and many studies show that leaf temps (NOT AIR TEMPS) of around 77f are most efficient. So how does a cool rootzone impact the plants negatively? Well it's 2 fold because of the cool temps the viscosity (measument of flow rate) of the sap will decrease so its harder for the plant to move the nutrients through the plant. The other is absorption and one fact is that in a cooler rootzone the concentration of nutrients is higher (but aqua you just said it slows absorption) well it does as the nutrients build up in the roots it can absorb less and this has a direct impact negatively on the plant. It may appear to be overwatered because the plant is now struggling to take up and use oxygen. Add that to the slowed transpiration rates and you have the same symtom many refer to overwatering which againnos lack of o2. Now take a cold rootzone where the plants slow water uptake and then add the saturation zone to it and you can see the road to correction and recover is a long one and can have huge impact on growth and yields.

So you your pots up off the floor

WET AND DRY CYCLES

in soil and peat with higher water tables or with wider pots or combination of wet and dry cycles are important. This is to allow the dry back (including the uptake of water from the saturation zone) to prevent symtoms of over watering and help with o2 levels. Remember the majority of roots will end up in the saturation zone with these media's or with wider pots. Which can become depleted of o2 quickly as gas exchange is lower in water and media made up of smaller particles. This is where pot size and shape are important for the size of plant. You have a small plant in large container and there is no way it can take up enough of the water in the saturation zone fast enough to get air exposure in a media that has low gas exchange and majority of the roots. So it's important to choose a pot size that will allow for this. It's also why using the finger method to gage watering is poor and lifting the pots is much better... when they are light you know they have taken up a good portion of the saturation zone and are ready to be watered again.

This is much less of an issue when using soiless like coco or peat/perlite.

I'm going to stop here for tonight and will edit and add to as I get time.

Thank you for this information, it's good to know whats right and I'm happy to absorb. Something I think is important as well is air circulation around the pots. If they're too tightly stacked together they won't dry well creating some of the problems you mentioned.

 

[SC69]

Ok lots of posts on how to water plants. So I thought I would put together a thread on how different factors contribute to different results that ppl see. This is again not my work so don't go giving me credit although I will add some to it.

This will be a long read based on my personal knowledge, opinions, research and others work to consolidate information for our members. I'm not presenting my opinions as facts so take from this what you like. I will be putting it in subsection format for easy reference.

First I want to make an important point to take into consideration before reading. The tap root will grow directly downwards to the bottom of the container before spreading out.

PERCHED WATER TABLE

What is it?

The perched water table is basically the height of the saturation zone where capillary action and gravity cancel eachother out. This area will be saturated with water and will be responsible most growers issues with watering practices especially in soil grows.

WHAT IS CAPILLARY ACTION

CAPILLARY action is is the combination of the cohesive and adhesive properties of water.

In short adhesion is water clinging to the media (think of it like wicking or soaking up)

Cohesion is where the water clings to itself.

So as the water is wicked up (adhesion) it pulls more water with it through Cohesion and at the point gravity and these properties cancel eachother out is the perched water table.

This perched water table will always remain the SAME HEIGHT and will always stay saturated unless taken up by the plants or evaporates when the pot dries out. No matter the container height, depth or volume of media. So if a tall skinny container had a perched water table of 1" then a short wide one of the same media will also have a perched water table of 1". Which means the ratio of water to air in a wide pot will be higher than a tall skinny pot which will have a higher air to water ratio... keep this in mind as we get further.

Different media's have different perched water tables. A more absorbent media will have a higher perched water table than a less absorbent media... REMEMBER THIS as it makes a big difference on pot selection for your media.

DIFFERENT MEDIA

Water holding capacity is directly related to the height of the perched water table so soils with more clay or silt and less sand will have a higher perched water table than those with more sand because sand is a larger particle.

The larger the overall particles of the media the lower the perched water table and better the drainage.

By adding things like perlite or vermiculite (while vermiculite is good at absorbing water it also improves drainage so its helpful in keeping a more even level of moisture throught the media while increasing drainage due to its size) we can lower the perched water table by reducing the wicking (adhesion) ability and creating more space between particles overall reducing the cohesion effect and inturn the height of the perched water table.

Media's like peat based or coco have a much higher drainage and lower perched water table than soil and are therefore less susceptible to over watering but will require more frequent watering due to the lower water holding capacity.

Adding thing like perlite or hydroton to the bottom of the pots will NOT reduce the water table but instead raise it. This is because as I said the height of the water table will not change for a given media. So if you add things like that to the bottom you are essentially just moving the water table up.

Basically the larger the particles IN the media the better drainage and lower the water table.

If you want to see the height of your perched water table use a clear cup with drain holes fill with media and saturate it. Wait a few hrs for drainage and then come back and look. You can see the difference in the varying media's if you want to experiment.

POT SIZE

I have already covered this a bit but my opinion is if you are using a media with a higher water table you will benefit from taller narrower pots and if using a media with a lower perched water table the shorter wider ones may benefit you depending on your watering practices.

I prefer the taller over wider no matter the media as I choose to water often and have a higher air holding capacity and lower water table but that can work against you if you can't water as frequently and as plants grow it can greatly increase the frequency required as the roots will be pulling the water out of that saturation zone quickly. So you may want to use taller pots for small plants and transplant into a wider one as they grow.

You also don't want a pot that's to tall and the top portion of the media is drying out to fast while the bottom is wet.

Let's use seedlings as an example take a solo cup or a large container... the water table will be the same height in either. I see sooo often ppl trying to water a tiny bit in circles or mist the surface and for lack of other words IT DEIVES ME NUTS. Why because the roots are so shallow they are not at risk of being over watered. Remember though tap roots grow straight down so we to be mindful as they grow depending on the gas exchange of the media that the majority of roots are not sitting in the saturated zone with poor gas exchange because this will cause lack of oxygen that we incorrectly refer to as overwatering which is actually the cause not the symptom.

It's important to fill containers to the top to give us a good amount of space above the perched water table that high in o2. If you fill a solo cup halfway with soil it's likely to be sitting in the saturation zone and will not do well.


Also going to make the point that plants will be most susceptible to overwatering when the roots first hit the bottom and spread out until they fill the bottom and start moving back up out of the saturation zone. So again it may be more beneficial to use a taller narrow pot for the early stages of growth (2-4 weekss depending on growth) and transplant into a wider pot as you go. After the transplant almost all of the roots will be above the saturation zone and it become much harder to over water. New roots will again work their way down into the saturation zone but you will have plenty above so its less likely to over water and why uppotting as you go I see as a benefit instead of starting in a large wide container.

POT MATERIAL

Some prefer plastic others fabric, air pots etc.

This can affect the perched water table by evaporation as the lager the exposed surface area the more evaporation that occurs from the media in say fabric pots. This imo has a few benefits.... slightly reducing the perched water table but more so the exposure for gas exchange that's happening and that's a good thing for o2 levels in the root zone that I feel are directly related to growth rates and I'll explain why going a bit off topic for a second.

It's no coincidence that the fastest growing media's have the highest amounts of o2 and gas exchange.... for eg aeroponics have unlimited to rich o2 and water. Hydro similar with slightly less o2, soiless media's such as coco and I would possible include peat and last soil. If you notice they are in order of growth rates and its not hard to see the difference in thier air holding capacity in that order. And the fact that larger particles also have a better gas exchange rate. This is important because the plants take in oxygen and expell co2 in the rootzone as do the microbes on top of that so good gas exchange is important for both.

Just a note... air pruning has nothing to do with the benefits of fabric pots all it does is signal the roots to grow in a different direction.

But let's get back on topic of watering and how it's affected.

TEMPERATURE AND HUMIDITY

The warmer the temps the more evaporation occurs.

The lower your humidity the more evaporation occurs

The more surface area exposed to air movement (wind) the more evaporation.

Think those don't need an explanation. But the difference in pot material coupled with these environmental factors will have an impact on your watering needs.

The temperature of the media not only affects evaporation but also directly affect the temperature of the plant and leaf temps. This has a large impact on nutrient uptake and transportation.

First let me say that this next part is opinion and I will gives my reasoning for my opinions. With the exception of hydro (leaving this part out as this post is about watering not hydro) roots like to be about the same temperature as the leaves contrary to what's talked about from many prominent growers in the industry but not all like Mr.Bruce Bugbee. IMO ideal root temps are the same as ideal leaf temps and overall plant temps especially since the root temps have a large impact on the plant and leaf temps. What are ideal temps imo and many studies show that leaf temps (NOT AIR TEMPS) of around 77f are most efficient. So how does a cool rootzone impact the plants negatively? Well it's 2 fold because of the cool temps the viscosity (measument of flow rate) of the sap will decrease so its harder for the plant to move the nutrients through the plant. The other is absorption and one fact is that in a cooler rootzone the concentration of nutrients is higher (but aqua you just said it slows absorption) well it does as the nutrients build up in the roots it can absorb less and this has a direct impact negatively on the plant. It may appear to be overwatered because the plant is now struggling to take up and use oxygen. Add that to the slowed transpiration rates and you have the same symtom many refer to overwatering which againnos lack of o2. Now take a cold rootzone where the plants slow water uptake and then add the saturation zone to it and you can see the road to correction and recover is a long one and can have huge impact on growth and yields.

So you your pots up off the floor

WET AND DRY CYCLES

in soil and peat with higher water tables or with wider pots or combination of wet and dry cycles are important. This is to allow the dry back (including the uptake of water from the saturation zone) to prevent symtoms of over watering and help with o2 levels. Remember the majority of roots will end up in the saturation zone with these media's or with wider pots. Which can become depleted of o2 quickly as gas exchange is lower in water and media made up of smaller particles. This is where pot size and shape are important for the size of plant. You have a small plant in large container and there is no way it can take up enough of the water in the saturation zone fast enough to get air exposure in a media that has low gas exchange and majority of the roots. So it's important to choose a pot size that will allow for this. It's also why using the finger method to gage watering is poor and lifting the pots is much better... when they are light you know they have taken up a good portion of the saturation zone and are ready to be watered again.

This is much less of an issue when using soiless like coco or peat/perlite.

I'm going to stop here for tonight and will edit and add to as I get time.

Hi there. Been a bit but you read my water report for me. I’ve now got 7, 1 month old gals and things have been pretty decent. On Monday I transplanted from solo cups to 3gal fabric. The issue…I researched enough to be dangerous (of course) long story short I fell in love with a particular brand of living soil from a farm in a neighboring state. I found out later (too late) that container size is a serious factor with living soil. That’s going to be rectified.

Anyway to the problem at hand. This stuff isn’t supposed to be “wet.” Just moist always, as should any I guess. Initially, they got a bit too little and had some obvious dry pockets. It probably didn’t matter but the stuff is supposed to be “activated.” I got a wetting agent and gave them some more. Apparently, a few more than others. I am pretty sure I have overwatered here. They are young. With this soil, I don’t know how long before it dries up a bit. Will they recover or are they drowning while I watch? I know you can’t say for sure. Odds doc? Haha.

Thank you in advance for any input.

 

[Aqua Man]

When you water the entire media saturate it so that is correct bit once you see runoff stop. You don't want to wash the nutrients out.

I see they are off the floor

Raise temps if below 75f to 78-80F

Back the light offbuntil they improve. A gentle airflow at the pots only will help...

And a little trick for your circumstances I think it was @Frankster mentioned... when you see over watering tilt the pot at a 45 degree angle for 5 -10 min. This will take advantage of the fact the water table will always stay the same height. So only the edge of the pot which is a massive difference in water from the entire pot.

 

[SC69]

When you water the entire media saturate it so that is correct bit once you see runoff stop. You don't want to wash the nutrients out.

I see they are off the floor

Raise temps if below 75f to 78-80F

Back the light offbuntil they improve. A gentle airflow at the pots only will help...

And a little trick for your circumstances I think it was @Frankster mentioned... when you see over watering tilt the pot at a 45 degree angle for 5 -10 min. This will take advantage of the fact the water table will always stay the same height. So only the edge of the pot which is a massive difference in water from the entire pot.

On it. Thank you!! I’ve already lowered the humidity and got the temp to stay at 74/75 but I can up it a bit still.

Off the floor, yes. I do try to listen. That was an early one. I had a friend try to talk me out of them after they were already here (the risers) That’s why we don’t ask him things anymore. Hah

Thanks again!

 

[DoobieBro462]

EurekAlert!!

Lol....could tbey use tbe fukushima water to grow hemp and phytoremediate the cesium out of the water instead of dumping it in the ocean? This sounds like a great idea!

Is there something im missing here?

If done without contaminating the soil its a great idea..it'd have to be done right. I think they can. What are they waiting for?

Looks like they are waiting for the Pacific Ocean to start boiling. Smh

 

[Rebeccalovato777]

Ok lots of posts on how to water plants. So I thought I would put together a thread on how different factors contribute to different results that ppl see.

This will be a long read based on my personal knowledge, opinions, research and others work to consolidate information for our members. I'm not presenting my opinions as facts so take from this what you like. I will be putting it in subsection format for easy reference.

First I want to make an important point to take into consideration before reading. The tap root will grow directly downwards to the bottom of the container before spreading out.

PERCHED WATER TABLE

What is it?

The perched water table is basically the height of the saturation zone where capillary action and gravity cancel eachother out. This area will be saturated with water and will be responsible most growers issues with watering practices especially in soil grows.

WHAT IS CAPILLARY ACTION

CAPILLARY action is is the combination of the cohesive and adhesive properties of water.

In short adhesion is water clinging to the media (think of it like wicking or soaking up)

Cohesion is where the water clings to itself.

So as the water is wicked up (adhesion) it pulls more water with it through Cohesion and at the point gravity and these properties cancel eachother out is the perched water table.

This perched water table will always remain the SAME HEIGHT and will always stay saturated unless taken up by the plants or evaporates when the pot dries out. No matter the container height, depth or volume of media. So if a tall skinny container had a perched water table of 1" then a short wide one of the same media will also have a perched water table of 1". Which means the ratio of water to air in a wide pot will be higher than a tall skinny pot which will have a higher air to water ratio... keep this in mind as we get further.

Different media's have different perched water tables. A more absorbent media will have a higher perched water table than a less absorbent media... REMEMBER THIS as it makes a big difference on pot selection for your media.

DIFFERENT MEDIA

Water holding capacity is directly related to the height of the perched water table so soils with more clay or silt and less sand will have a higher perched water table than those with more sand because sand is a larger particle.

The larger the overall particles of the media the lower the perched water table and better the drainage.

By adding things like perlite or vermiculite (while vermiculite is good at absorbing water it also improves drainage so its helpful in keeping a more even level of moisture throught the media while increasing drainage due to its size) we can lower the perched water table by reducing the wicking (adhesion) ability and creating more space between particles overall reducing the cohesion effect and inturn the height of the perched water table.

Media's like peat based or coco have a much higher drainage and lower perched water table than soil and are therefore less susceptible to over watering but will require more frequent watering due to the lower water holding capacity.

Adding thing like perlite or hydroton to the bottom of the pots will NOT reduce the water table but instead raise it. This is because as I said the height of the water table will not change for a given media. So if you add things like that to the bottom you are essentially just moving the water table up.

Basically the larger the particles IN the media the better drainage and lower the water table.

If you want to see the height of your perched water table use a clear cup with drain holes fill with media and saturate it. Wait a few hrs for drainage and then come back and look. You can see the difference in the varying media's if you want to experiment.

POT SIZE

I have already covered this a bit but my opinion is if you are using a media with a higher water table you will benefit from taller narrower pots and if using a media with a lower perched water table the shorter wider ones may benefit you depending on your watering practices.

I prefer the taller over wider no matter the media as I choose to water often and have a higher air holding capacity and lower water table but that can work against you if you can't water as frequently and as plants grow it can greatly increase the frequency required as the roots will be pulling the water out of that saturation zone quickly. So you may want to use taller pots for small plants and transplant into a wider one as they grow.

You also don't want a pot that's to tall and the top portion of the media is drying out to fast while the bottom is wet.

Let's use seedlings as an example take a solo cup or a large container... the water table will be the same height in either. I see sooo often ppl trying to water a tiny bit in circles or mist the surface and for lack of other words IT DEIVES ME NUTS. Why because the roots are so shallow they are not at risk of being over watered. Remember though tap roots grow straight down so we to be mindful as they grow depending on the gas exchange of the media that the majority of roots are not sitting in the saturated zone with poor gas exchange because this will cause lack of oxygen that we incorrectly refer to as overwatering which is actually the cause not the symptom.

It's important to fill containers to the top to give us a good amount of space above the perched water table that high in o2. If you fill a solo cup halfway with soil it's likely to be sitting in the saturation zone and will not do well.


Also going to make the point that plants will be most susceptible to overwatering when the roots first hit the bottom and spread out until they fill the bottom and start moving back up out of the saturation zone. So again it may be more beneficial to use a taller narrow pot for the early stages of growth (2-4 weekss depending on growth) and transplant into a wider pot as you go. After the transplant almost all of the roots will be above the saturation zone and it become much harder to over water. New roots will again work their way down into the saturation zone but you will have plenty above so its less likely to over water and why uppotting as you go I see as a benefit instead of starting in a large wide container.

POT MATERIAL

Some prefer plastic others fabric, air pots etc.

This can affect the perched water table by evaporation as the lager the exposed surface area the more evaporation that occurs from the media in say fabric pots. This imo has a few benefits.... slightly reducing the perched water table but more so the exposure for gas exchange that's happening and that's a good thing for o2 levels in the root zone that I feel are directly related to growth rates and I'll explain why going a bit off topic for a second.

It's no coincidence that the fastest growing media's have the highest amounts of o2 and gas exchange.... for eg aeroponics have unlimited to rich o2 and water. Hydro similar with slightly less o2, soiless media's such as coco and I would possible include peat and last soil. If you notice they are in order of growth rates and its not hard to see the difference in thier air holding capacity in that order. And the fact that larger particles also have a better gas exchange rate. This is important because the plants take in oxygen and expell co2 in the rootzone as do the microbes on top of that so good gas exchange is important for both.

Just a note... air pruning has nothing to do with the benefits of fabric pots all it does is signal the roots to grow in a different direction.

But let's get back on topic of watering and how it's affected.

TEMPERATURE AND HUMIDITY

The warmer the temps the more evaporation occurs.

The lower your humidity the more evaporation occurs

The more surface area exposed to air movement (wind) the more evaporation.

Think those don't need an explanation. But the difference in pot material coupled with these environmental factors will have an impact on your watering needs.

The temperature of the media not only affects evaporation but also directly affect the temperature of the plant and leaf temps. This has a large impact on nutrient uptake and transportation.

First let me say that this next part is opinion and I will gives my reasoning for my opinions. With the exception of hydro (leaving this part out as this post is about watering not hydro) roots like to be about the same temperature as the leaves contrary to what's talked about from many prominent growers in the industry but not all like Mr.Bruce Bugbee. IMO ideal root temps are the same as ideal leaf temps and overall plant temps especially since the root temps have a large impact on the plant and leaf temps. What are ideal temps imo and many studies show that leaf temps (NOT AIR TEMPS) of around 77f are most efficient. So how does a cool rootzone impact the plants negatively? Well it's 2 fold because of the cool temps the viscosity (measument of flow rate) of the sap will decrease so its harder for the plant to move the nutrients through the plant. The other is absorption and one fact is that in a cooler rootzone the concentration of nutrients is higher (but aqua you just said it slows absorption) well it does as the nutrients build up in the roots it can absorb less and this has a direct impact negatively on the plant. It may appear to be overwatered because the plant is now struggling to take up and use oxygen. Add that to the slowed transpiration rates and you have the same symtom many refer to overwatering which againnos lack of o2. Now take a cold rootzone where the plants slow water uptake and then add the saturation zone to it and you can see the road to correction and recover is a long one and can have huge impact on growth and yields.

So you your pots up off the floor

WET AND DRY CYCLES

in soil and peat with higher water tables or with wider pots or combination of wet and dry cycles are important. This is to allow the dry back (including the uptake of water from the saturation zone) to prevent symtoms of over watering and help with o2 levels. Remember the majority of roots will end up in the saturation zone with these media's or with wider pots. Which can become depleted of o2 quickly as gas exchange is lower in water and media made up of smaller particles. This is where pot size and shape are important for the size of plant. You have a small plant in large container and there is no way it can take up enough of the water in the saturation zone fast enough to get air exposure in a media that has low gas exchange and majority of the roots. So it's important to choose a pot size that will allow for this. It's also why using the finger method to gage watering is poor and lifting the pots is much better... when they are light you know they have taken up a good portion of the saturation zone and are ready to be watered again.

This is much less of an issue when using soiless like coco or peat/perlite.

I'm going to stop here for tonight and will edit and add to as I get time.

I had issues when I first started I used basic soil it was an awful experience making me read more the soil I switched to is amazing draining instantly my plants love it!

 

[Neueregel]

@Aqua Man How's it going eh? i was reading what you wrote here, and i'm still confused. I use fox farm ocean forest soil mix. so what would my water table be in a 5 gallon fabric pot? good stuff you got here bud.

 

[PurpleBudz]

Ok lots of posts on how to water plants. So I thought I would put together a thread on how different factors contribute to different results that ppl see.

This will be a long read based on my personal knowledge, opinions, research and others work to consolidate information for our members. I'm not presenting my opinions as facts so take from this what you like. I will be putting it in subsection format for easy reference.

First I want to make an important point to take into consideration before reading. The tap root will grow directly downwards to the bottom of the container before spreading out.

PERCHED WATER TABLE

What is it?

The perched water table is basically the height of the saturation zone where capillary action and gravity cancel eachother out. This area will be saturated with water and will be responsible most growers issues with watering practices especially in soil grows.

WHAT IS CAPILLARY ACTION

CAPILLARY action is is the combination of the cohesive and adhesive properties of water.

In short adhesion is water clinging to the media (think of it like wicking or soaking up)

Cohesion is where the water clings to itself.

So as the water is wicked up (adhesion) it pulls more water with it through Cohesion and at the point gravity and these properties cancel eachother out is the perched water table.

This perched water table will always remain the SAME HEIGHT and will always stay saturated unless taken up by the plants or evaporates when the pot dries out. No matter the container height, depth or volume of media. So if a tall skinny container had a perched water table of 1" then a short wide one of the same media will also have a perched water table of 1". Which means the ratio of water to air in a wide pot will be higher than a tall skinny pot which will have a higher air to water ratio... keep this in mind as we get further.

Different media's have different perched water tables. A more absorbent media will have a higher perched water table than a less absorbent media... REMEMBER THIS as it makes a big difference on pot selection for your media.

DIFFERENT MEDIA

Water holding capacity is directly related to the height of the perched water table so soils with more clay or silt and less sand will have a higher perched water table than those with more sand because sand is a larger particle.

The larger the overall particles of the media the lower the perched water table and better the drainage.

By adding things like perlite or vermiculite (while vermiculite is good at absorbing water it also improves drainage so its helpful in keeping a more even level of moisture throught the media while increasing drainage due to its size) we can lower the perched water table by reducing the wicking (adhesion) ability and creating more space between particles overall reducing the cohesion effect and inturn the height of the perched water table.

Media's like peat based or coco have a much higher drainage and lower perched water table than soil and are therefore less susceptible to over watering but will require more frequent watering due to the lower water holding capacity.

Adding thing like perlite or hydroton to the bottom of the pots will NOT reduce the water table but instead raise it. This is because as I said the height of the water table will not change for a given media. So if you add things like that to the bottom you are essentially just moving the water table up.

Basically the larger the particles IN the media the better drainage and lower the water table.

If you want to see the height of your perched water table use a clear cup with drain holes fill with media and saturate it. Wait a few hrs for drainage and then come back and look. You can see the difference in the varying media's if you want to experiment.

POT SIZE

I have already covered this a bit but my opinion is if you are using a media with a higher water table you will benefit from taller narrower pots and if using a media with a lower perched water table the shorter wider ones may benefit you depending on your watering practices.

I prefer the taller over wider no matter the media as I choose to water often and have a higher air holding capacity and lower water table but that can work against you if you can't water as frequently and as plants grow it can greatly increase the frequency required as the roots will be pulling the water out of that saturation zone quickly. So you may want to use taller pots for small plants and transplant into a wider one as they grow.

You also don't want a pot that's to tall and the top portion of the media is drying out to fast while the bottom is wet.

Let's use seedlings as an example take a solo cup or a large container... the water table will be the same height in either. I see sooo often ppl trying to water a tiny bit in circles or mist the surface and for lack of other words IT DEIVES ME NUTS. Why because the roots are so shallow they are not at risk of being over watered. Remember though tap roots grow straight down so we to be mindful as they grow depending on the gas exchange of the media that the majority of roots are not sitting in the saturated zone with poor gas exchange because this will cause lack of oxygen that we incorrectly refer to as overwatering which is actually the cause not the symptom.

It's important to fill containers to the top to give us a good amount of space above the perched water table that high in o2. If you fill a solo cup halfway with soil it's likely to be sitting in the saturation zone and will not do well.


Also going to make the point that plants will be most susceptible to overwatering when the roots first hit the bottom and spread out until they fill the bottom and start moving back up out of the saturation zone. So again it may be more beneficial to use a taller narrow pot for the early stages of growth (2-4 weekss depending on growth) and transplant into a wider pot as you go. After the transplant almost all of the roots will be above the saturation zone and it become much harder to over water. New roots will again work their way down into the saturation zone but you will have plenty above so its less likely to over water and why uppotting as you go I see as a benefit instead of starting in a large wide container.

POT MATERIAL

Some prefer plastic others fabric, air pots etc.

This can affect the perched water table by evaporation as the lager the exposed surface area the more evaporation that occurs from the media in say fabric pots. This imo has a few benefits.... slightly reducing the perched water table but more so the exposure for gas exchange that's happening and that's a good thing for o2 levels in the root zone that I feel are directly related to growth rates and I'll explain why going a bit off topic for a second.

It's no coincidence that the fastest growing media's have the highest amounts of o2 and gas exchange.... for eg aeroponics have unlimited to rich o2 and water. Hydro similar with slightly less o2, soiless media's such as coco and I would possible include peat and last soil. If you notice they are in order of growth rates and its not hard to see the difference in thier air holding capacity in that order. And the fact that larger particles also have a better gas exchange rate. This is important because the plants take in oxygen and expell co2 in the rootzone as do the microbes on top of that so good gas exchange is important for both.

Just a note... air pruning has nothing to do with the benefits of fabric pots all it does is signal the roots to grow in a different direction.

But let's get back on topic of watering and how it's affected.

TEMPERATURE AND HUMIDITY

The warmer the temps the more evaporation occurs.

The lower your humidity the more evaporation occurs

The more surface area exposed to air movement (wind) the more evaporation.

Think those don't need an explanation. But the difference in pot material coupled with these environmental factors will have an impact on your watering needs.

The temperature of the media not only affects evaporation but also directly affect the temperature of the plant and leaf temps. This has a large impact on nutrient uptake and transportation.

First let me say that this next part is opinion and I will gives my reasoning for my opinions. With the exception of hydro (leaving this part out as this post is about watering not hydro) roots like to be about the same temperature as the leaves contrary to what's talked about from many prominent growers in the industry but not all like Mr.Bruce Bugbee. IMO ideal root temps are the same as ideal leaf temps and overall plant temps especially since the root temps have a large impact on the plant and leaf temps. What are ideal temps imo and many studies show that leaf temps (NOT AIR TEMPS) of around 77f are most efficient. So how does a cool rootzone impact the plants negatively? Well it's 2 fold because of the cool temps the viscosity (measument of flow rate) of the sap will decrease so its harder for the plant to move the nutrients through the plant. The other is absorption and one fact is that in a cooler rootzone the concentration of nutrients is higher (but aqua you just said it slows absorption) well it does as the nutrients build up in the roots it can absorb less and this has a direct impact negatively on the plant. It may appear to be overwatered because the plant is now struggling to take up and use oxygen. Add that to the slowed transpiration rates and you have the same symtom many refer to overwatering which againnos lack of o2. Now take a cold rootzone where the plants slow water uptake and then add the saturation zone to it and you can see the road to correction and recover is a long one and can have huge impact on growth and yields.

So you your pots up off the floor

WET AND DRY CYCLES

in soil and peat with higher water tables or with wider pots or combination of wet and dry cycles are important. This is to allow the dry back (including the uptake of water from the saturation zone) to prevent symtoms of over watering and help with o2 levels. Remember the majority of roots will end up in the saturation zone with these media's or with wider pots. Which can become depleted of o2 quickly as gas exchange is lower in water and media made up of smaller particles. This is where pot size and shape are important for the size of plant. You have a small plant in large container and there is no way it can take up enough of the water in the saturation zone fast enough to get air exposure in a media that has low gas exchange and majority of the roots. So it's important to choose a pot size that will allow for this. It's also why using the finger method to gage watering is poor and lifting the pots is much better... when they are light you know they have taken up a good portion of the saturation zone and are ready to be watered again.

This is much less of an issue when using soiless like coco or peat/perlite.

I'm going to stop here for tonight and will edit and add to as I get time.

I add big rocks to the bottom of my 5gal buckets; about 4 too 5" up from bottom for organic soil to sit on top of, the rocks create air gaps for air exchange and drainage, I also drill out 3/8th inch holes along sides of my bucket half way up for the same purpose. Excellent drainage and air flow. Still having some slight issues idk, maybe I am not and not just bothered by a yellow leaf here and there lol