Help with seedling watering in coco?!

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Nectarivorous

Nectarivorous

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Hi all,

First time grower, been looking for a place to ask my dumb questions, hopefully get some assistance and then be able to one day offer and myself once I know more than nothing! Have been super impressed by all the discussion, and some amazing experts on here. Given it's a watering question perhaps Aquaman can help but any help appreciated.

I have 4x Green Crush seedlings in large pots with Coco. Having found mixed info I used no Perl/Vermic but next time will be doing this. In a 4x4 tent, 2x Mars TSL 2000 LED set about 30 inches above set to 30% - 350 ppfd measured at the plants.

I have a nute tank using seeding strength mix of Canna A&B, pH down to 5.9. Temps 70-76, RH consistent around 60-63.

A lot of my info has come from YouTube as well as a lot of reading from commercial growers, Prof Bugbee, MR Canuck, others. Having read online that seeds have all the nutes they need for the first few weeks, what was not mentioned was that this is in soil, not in a dead neutral medium. As a result they received no nutes for first 9 days, and was doing silly little spray bottle waters and avoiding a lot of water, again because of online advice that clearly was more for soil than water.

Plants don't look miserable, they only have cotyledon and first leaves, but all have shot up and have second leaves starting, but look quite yellow. I have it in good advice that new growth can be quite yellow, and that Green Crush can have very pale or even yellow leaves naturally. I guess I'm struggling to determine if I'm underwatering, overwatering or suffering lack of nutes due to none for first week.

Running a run to waste system, delivers 250 ml per 30 seconds per plant. There was no pre soaking of Coco as again I didn't know that. So yesterday I turned the pump on for the first time (have a fish tank pump with an airball aerating the water), and gave each plant 1.5L around the outside of the pot to soak the medium. No run off. So I ran for 30 seconds, total of 1 litre across the tent, and got 10% run off, beautiful. But still looking yellow today despite nutrients, and maybe starting to curl down a little? Do I need to keep doing what I'm doing and wait for the nutes to help? Do I need to water less or more? Are they fine and I do nothing? Pictures attached, hopefully they are good enough to give you an idea where we're at, any help GREATLY appreciated.

Peace and blaze crew.
 
Nectarivorous

Nectarivorous

325
63
I'm using an iPhone lux meter with great reviews based on comparisons to more expensive metres. Just measured lux at the plants and it's about 12,500. I will say I got some info which I misinterpreted and moved my lamps much closer for about 2 days when the plants were very young, and had no light meter. Suspect they were getting way too much light for that period. Wondered if that has bleached them but not recovering since then and as you can see new shoots are same colour. Help haha 😂
 
Aqua Man

Aqua Man

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Hi all,

First time grower, been looking for a place to ask my dumb questions, hopefully get some assistance and then be able to one day offer and myself once I know more than nothing! Have been super impressed by all the discussion, and some amazing experts on here. Given it's a watering question perhaps Aquaman can help but any help appreciated.

I have 4x Green Crush seedlings in large pots with Coco. Having found mixed info I used no Perl/Vermic but next time will be doing this. In a 4x4 tent, 2x Mars TSL 2000 LED set about 30 inches above set to 30% - 350 ppfd measured at the plants.

I have a nute tank using seeding strength mix of Canna A&B, pH down to 5.9. Temps 70-76, RH consistent around 60-63.

A lot of my info has come from YouTube as well as a lot of reading from commercial growers, Prof Bugbee, MR Canuck, others. Having read online that seeds have all the nutes they need for the first few weeks, what was not mentioned was that this is in soil, not in a dead neutral medium. As a result they received no nutes for first 9 days, and was doing silly little spray bottle waters and avoiding a lot of water, again because of online advice that clearly was more for soil than water.

Plants don't look miserable, they only have cotyledon and first leaves, but all have shot up and have second leaves starting, but look quite yellow. I have it in good advice that new growth can be quite yellow, and that Green Crush can have very pale or even yellow leaves naturally. I guess I'm struggling to determine if I'm underwatering, overwatering or suffering lack of nutes due to none for first week.

Running a run to waste system, delivers 250 ml per 30 seconds per plant. There was no pre soaking of Coco as again I didn't know that. So yesterday I turned the pump on for the first time (have a fish tank pump with an airball aerating the water), and gave each plant 1.5L around the outside of the pot to soak the medium. No run off. So I ran for 30 seconds, total of 1 litre across the tent, and got 10% run off, beautiful. But still looking yellow today despite nutrients, and maybe starting to curl down a little? Do I need to keep doing what I'm doing and wait for the nutes to help? Do I need to water less or more? Are they fine and I do nothing? Pictures attached, hopefully they are good enough to give you an idea where we're at, any help GREATLY appreciated.

Peace and blaze crew.
I'm going to link 2 posts at the end. 1 for coco and one to help you understand how your pot size and material among other things will affect how you water.

I suggest easing into everything and it seems you have done yourself a great service by doing a good amount of research.

I would drop par to 200-250 as the high the light the more demand on the plants, environmental conditions and nutrition.

Coco should ALWAYS be watered with nutrients added... seedlings actually carry enough nutrients for them to sprout but in soil there is enough to support them.

I'm not sure what your source water is but I would suggest around 200-300ppm of nutrients. The demand will increase fairly quick over the first few weeks. Bit can go over that after.

With no perlite added your watering frequency will go way down especially in larger pots. For future I would do taller narrower pots.

Your temp can increase to around 80f if you have the ability. Humidity sounds perfect.

Ok I'll link some posts then check back in a bit. If you watered without nutrients I would give them a dose. Your seedlings look good so far so if you have any worries you don't need to.


 
Nectarivorous

Nectarivorous

325
63
I'm going to link 2 posts at the end. 1 for coco and one to help you understand how your pot size and material among other things will affect how you water.

I suggest easing into everything and it seems you have done yourself a great service by doing a good amount of research.

I would drop par to 200-250 as the high the light the more demand on the plants, environmental conditions and nutrition.

Coco should ALWAYS be watered with nutrients added... seedlings actually carry enough nutrients for them to sprout but in soil there is enough to support them.

I'm not sure what your source water is but I would suggest around 200-300ppm of nutrients. The demand will increase fairly quick over the first few weeks. Bit can go over that after.

With no perlite added your watering frequency will go way down especially in larger pots. For future I would do taller narrower pots.

Your temp can increase to around 80f if you have the ability. Humidity sounds perfect.

Ok I'll link some posts then check back in a bit. If you watered without nutrients I would give them a dose. Your seedlings look good so far so if you have any worries you don't need to.


Mate can I please just say thank you for the prompt response, it takes such a load off to get reassurance from someone that knows their shit, I don't know if this pays your way but if you just do it to support growers and the community, man it's awesome. Love this about this community.

Seems to me from reading that colour is one of those things that doesn't need people speaking absolutes. 'your leaves should be xxx colour green' sounds like saying 'your Roses should be red' - but what if they are yellow roses? Seems to me there is a lot of genetic variation at play that is ignored in statements like that.

All the water I put through yesterday was the dosed and pH'd water, so they're getting that now. Gave them 500ml each before I posted earlier, but will back off based on advice re perlite. I had also adjusted the lights down based on another comment of yours saying under 10k lux, so switched to lux and they are around 10-10,500, roughly 230 ppfd at plants. Totally get what you say about resources, hadn't even considered that one can actually induce nutrient deficiency just by adding too much 'fuel' (photons).

A thought - would you dig out the middle section carefully and remix the Coco with perlite? Or is the risk of disturbance to roots too great. If so I'll just have to go carefully while they're young and look at perlite (or vermiculite as per prof Bugbee). I'm assuming that the overwatering problem is going to become something of a non issue once they hit heavy veg/flower and we move up to 900-950 ppfd as measured with lights set 14 inches above canopy.

Main thing was to get some peace of mind though which you've delivered in spades. My gut was telling me they looked healthy regardless of being a little paler than the interwebs said they 'should' be, good to know I can trust my instincts to some extent. Cheers man.
 
Aqua Man

Aqua Man

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Mate can I please just say thank you for the prompt response, it takes such a load off to get reassurance from someone that knows their shit, I don't know if this pays your way but if you just do it to support growers and the community, man it's awesome. Love this about this community.

Seems to me from reading that colour is one of those things that doesn't need people speaking absolutes. 'your leaves should be xxx colour green' sounds like saying 'your Roses should be red' - but what if they are yellow roses? Seems to me there is a lot of genetic variation at play that is ignored in statements like that.

All the water I put through yesterday was the dosed and pH'd water, so they're getting that now. Gave them 500ml each before I posted earlier, but will back off based on advice re perlite. I had also adjusted the lights down based on another comment of yours saying under 10k lux, so switched to lux and they are around 10-10,500, roughly 230 ppfd at plants. Totally get what you say about resources, hadn't even considered that one can actually induce nutrient deficiency just by adding too much 'fuel' (photons).

A thought - would you dig out the middle section carefully and remix the Coco with perlite? Or is the risk of disturbance to roots too great. If so I'll just have to go carefully while they're young and look at perlite (or vermiculite as per prof Bugbee). I'm assuming that the overwatering problem is going to become something of a non issue once they hit heavy veg/flower and we move up to 900-950 ppfd as measured with lights set 14 inches above canopy.

Main thing was to get some peace of mind though which you've delivered in spades. My gut was telling me they looked healthy regardless of being a little paler than the interwebs said they 'should' be, good to know I can trust my instincts to some extent. Cheers man.
Volunteer but this site has a community and owner that just makes you want to be part of it and very honored to be a staff member.

I wouldn't transplant personally I think you will be fine. I think you could if you wanted though. I'll leave that up to you. Personally I like smaller taller pots but they do need watered significantly more often.
 
Nectarivorous

Nectarivorous

325
63
Volunteer but this site has a community and owner that just makes you want to be part of it and very honored to be a staff member.

I wouldn't transplant personally I think you will be fine. I think you could if you wanted though. I'll leave that up to you. Personally I like smaller taller pots but they do need watered significantly more often.
Thanks mate. I think I'll just follow your article and water according to my current setup then look at adding vermiculite next time. I think it's good to try everything, that way you know why the ones that didn't work, didn't work. I can compare same strain with and without Perl/vermiculite, good learning exercise.

I have sort of parceled out my costs by leaving things like carbon filter until they're needed, got a pH pen but thought I'll leave the EC pen until later. I'm now working out that this seems to be the MOST crucial during seedling. I'm picking one up tomorrow. ☺️
 
Aqua Man

Aqua Man

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Thanks mate. I think I'll just follow your article and water according to my current setup then look at adding vermiculite next time. I think it's good to try everything, that way you know why the ones that didn't work, didn't work. I can compare same strain with and without Perl/vermiculite, good learning exercise.

I have sort of parceled out my costs by leaving things like carbon filter until they're needed, got a pH pen but thought I'll leave the EC pen until later. I'm now working out that this seems to be the MOST crucial during seedling. I'm picking one up tomorrow. ☺️
I'd say your ok.. just feed 1/4-1/2 or so and they should be fine until you get one if you get decent runoff
 
Nectarivorous

Nectarivorous

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I'd say your ok.. just feed 1/4-1/2 or so and they should be fine until you get one if you get decent runoff
Awesome. Sorry to bother, assuming you mean 1/4-1/2 strength on the Canna bottle? If so that's great because I did half! Will wait for it to get a little drier though given there is no perlite. To get run off in these boys probably will need to water every two days rather than one. Unless that's a bad idea... Oh man... 😂
 
Aqua Man

Aqua Man

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Awesome. Sorry to bother, assuming you mean 1/4-1/2 strength on the Canna bottle? If so that's great because I did half! Will wait for it to get a little drier though given there is no perlite. To get run off in these boys probably will need to water every two days rather than one. Unless that's a bad idea... Oh man... 😂
No need for them to dry... but in pots that size it prob be a few days before you need to water.
 
Nectarivorous

Nectarivorous

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No need for them to dry... but in pots that size it prob be a few days before you need to water.
Awesome mate great tips. Will aim to just as required, but always full soak with 10-20 runoff. To answer your earlier question I'm using tap water that lives in an open tank outside for a few days to dechlorination, which I then amend with Canna A & B. Will water with correct run off as advised then go forward with the EC meter.
 
Aqua Man

Aqua Man

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Awesome mate great tips. Will aim to just as required, but always full soak with 10-20 runoff. To answer your earlier question I'm using tap water that lives in an open tank outside for a few days to dechlorination, which I then amend with Canna A & B. Will water with correct run off as advised then go forward with the EC meter.
No need to dechlorinate the max allowable in drinking water is 4ppm and hardly ever see over 2ppm. On top of that most water supplies use chloramine now and that will stay for a week or longer unlike chlorine that will off gas in 24 hrs.

If you are concerned about chloramine then you can use ascorbic acid (vitamin C) to neutralize it. 1 gram will neutralize 1ppm I'm 100 gallons of water.
 
Nectarivorous

Nectarivorous

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No need to dechlorinate the max allowable in drinking water is 4ppm and hardly ever see over 2ppm. On top of that most water supplies use chloramine now and that will stay for a week or longer unlike chlorine that will off gas in 24 hrs.

If you are concerned about chloramine then you can use ascorbic acid (vitamin C) to neutralize it. 1 gram will neutralize 1ppm I'm 100 gallons of water.
Awesome thank you. Funny how many people talk about dechlorination as though it's gospel, never thought to look up actual levels though. No chloramination where I live because fish owners won't have it 😂 Chlorine is regularly tested at 0.5-1.5 ppm. So one less thing to worry about. I imagine anything that's going to off gas will do it from the nute tank with the help of the oxygenation ball. Plants are starting to shoot up as they access the nutes. Soil plenty most still, I'm gathering that essentially it's enough at this stage for the roots to be in contact with some moisture, which they defo still are. Feel like I can relax a little more and let them do their thing now I know there's no major issues going on.
 
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Aqua Man

Aqua Man

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Awesome thank you. Funny how many people talk about dechlorination as though it's gospel, never thought to look up actual levels though. No chloramination where I live because fish owners won't have it 😂 Chlorine is regularly tested at 0.5-1.5 ppm. So one less thing to worry about. I imagine anything that's going to gas off will do it from the nute tank with the help of the oxygenation ball. Plants are starting to shoot up as they access the nutes. Soil plenty most still, I'm gathering that essentially it's enough at this stage for the roots to be in contact with some moisture, which they defo still are. Feel like I can relax a little more and let them do their thing now I know there's no major issues going on.
Think of it like hydro.... root are completely submerged in water.... the issue is o2 not water. Coco has a great air holding capacity and gas exchange. This is why it's almost impossible to overwater. Overwatering is NOT to much water, it's lack of oxygen. In soil the air holding capacity and gas exchange are not enough to support it being saturated with water. And that's why it needs a wet dry cycle.
 
Nectarivorous

Nectarivorous

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Makes total sense. I think i have been overcomplicating the water thing, having read your articles on it. I literally just need to run 5% of pot volume through and see if I get 10% run off. If I don't I need to water more often. If more then I can wait longer between waterings.
 
Nectarivorous

Nectarivorous

325
63
Think of it like hydro.... root are completely submerged in water.... the issue is o2 not water. Coco has a great air holding capacity and gas exchange. This is why it's almost impossible to overwater. Overwatering is NOT to much water, it's lack of oxygen. In soil the air holding capacity and gas exchange are not enough to support it being saturated with water. And that's why it needs a wet dry cycle.
I'm assuming also the oxygenation of the water assists with preventing an imbalance of water to O2?
 
Aqua Man

Aqua Man

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I'm assuming also the oxygenation of the water assists with preventing an imbalance of water to O2?
In drain to waste its not needed but it will aid in gas exchange. I use a small water pump to flume the water.... does the same thing. It's not the air bubble that oxygenate the water. It's the surface agitation they create o2 is a very hard gas to dissolve in water but o2 starts to drop below equilibrium its becomes easier and the lower it goes the easier its dissolved and replenished.

Co2 on the other hand is quite easily dissolved in water again at equilibrium just because it's easily dissolved does not mean it will just keep absorbing it. Likewise easily off gassed. You see this in tap water. As both gasses are more easily dissolved under pressure. This is why we have aeration screen in our faucets... to aod in the removal of co2 as it come out of a pressurized system. Not to catch shit in the water although that helps for that purpose also.

The goal is to create water column mixing and surface agitation... either by air stone, waterfall, fluming etc. It doesn't matter this helps keep the gases at equilibrium. The main culprit is co2 as it forms carbonic acid when dissolved and will lower PH. Flint Michigan is a prime example of this as wacidic water will erode lead pipes and coatings that then contaminate the water supply.

Tldr: water column mixing and surface agitation... important
 
Nectarivorous

Nectarivorous

325
63
In drain to waste its not needed but it will aid in gas exchange. I use a small water pump to flume the water.... does the same thing. It's not the air bubble that oxygenate the water. It's the surface agitation they create o2 is a very hard gas to dissolve in water but o2 starts to drop below equilibrium its becomes easier and the lower it goes the easier its dissolved and replenished.

Co2 on the other hand is quite easily dissolved in water again at equilibrium just because it's easily dissolved does not mean it will just keep absorbing it. Likewise easily off gassed. You see this in tap water. As both gasses are more easily dissolved under pressure. This is why we have aeration screen in our faucets... to aod in the removal of co2 as it come out of a pressurized system. Not to catch shit in the water although that helps for that purpose also.

The goal is to create water column mixing and surface agitation... either by air stone, waterfall, fluming etc. It doesn't matter this helps keep the gases at equilibrium. The main culprit is co2 as it forms carbonic acid when dissolved and will lower PH. Flint Michigan is a prime example of this as wacidic water will erode lead pipes and coatings that then contaminate the water supply.

Tldr: water column mixing and surface agitation... important

Hi mate,

Just in the interest of 'getting my eye in'. Happy now that I understand the process of working out 'how much' to give, and from what I understand now not the risk of overwatering in any case as compared to soil. The attached photo is after I stirred up the top to integrate a bit as the top layer was dry. You can see where I've dug and there is water just below. Would you be happy with that amount of water to leave them for now? Is it safe to say it's not going to hurt to water them with 10% run off? Last watered yesterday, but only 500ml each and no run off, don't want to leave stuff sitting in there too long before flushing again. Also the plants have responded wonderfully to the last two days' nutes so I'm keen to give them more! But much more keen to get a true feel for the process at this early stage and become a great grower. Input requested and appreciated ☺️
 
Aqua Man

Aqua Man

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Hi mate,

Just in the interest of 'getting my eye in'. Happy now that I understand the process of working out 'how much' to give, and from what I understand now not the risk of overwatering in any case as compared to soil. The attached photo is after I stirred up the top to integrate a bit as the top layer was dry. You can see where I've dug and there is water just below. Would you be happy with that amount of water to leave them for now? Is it safe to say it's not going to hurt to water them with 10% run off? Last watered yesterday, but only 500ml each and no run off, don't want to leave stuff sitting in there too long before flushing again. Also the plants have responded wonderfully to the last two days' nutes so I'm keen to give them more! But much more keen to get a true feel for the process at this early stage and become a great grower. Input requested and appreciated ☺️
I would feed until runoff and the pot is saturated then it likely your good for several days in those pots with seedlings.
 

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