HELP! Plants wilting and yellowing!

[KeytheCaregiver]

Check at the center right under roots. I bet it's wet, it's the most common culprit. It can be very dry everywhere else and dry there. Unless your soil drains extremely well every 2 to3 days is too much water.

How often do you recommend watering/feeding through flower in 9x9 - 12x12 pots?
We are used to our plants drinking heavy at this point in flower but with the Gnat, Light burn, and Powdery Mildew. They've been through hell and back.

 

[Aqua Man]

First stop flushing your removing all the buffering capacity of the soil. Second start feeding some available nutrients.your olants are hungry and overwatering prevents them from getting oxygen. Dont water on a schedule water when they need it. Judge by lifting the pots if your not sure then they aren’t ready.

Back the lights off to 50% for now.

Read this to understand watering.

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

Discuss different watering methods for growing your own weed from seeds. Our community members give helpful tips on how pot size and material, as well as environmental factors affect growing cannabis.

www.thcfarmer.com

 

[Aqua Man]

Ill add a few more links that you need to read closely dont just skim theough these. Read until you understand and ask any questions you have.

 

[Aqua Man]

Marijuana pH Levels for Growing Weed: A Basic Explanation

In this article, we discuss proper pH levels for your weed plants; alkalinity, soil pH, tap water, and the effects of nutrients on pH when growing marijuana

www.thcfarmer.com

 

[Aqua Man]

VPD (vapor pressure deficit)

Ok i was gonna sit down and write out a whole article but i have been lazy so instead instead I'm going to copy paste because im lazy. This is not my work so let start. You may find this very long but its worth the read. Some may want to skip ahead. I have added here and there to what i feel is...

www.thcfarmer.com

 

[Aqua Man]

You need to back the light off always. When you see a problem…. Any problem. Light drives the plants and all you can do is make it worse faster by adding more light or keeping a high intensity

 

[Aqua Man]

You need a balanced nutrient not just bloom because they are in flower… they are nitrogen starved

 

[Aqua Man]

Going for a bike ride will chexk when i get back. Read those 3 and understand those 3 links.

Post any questions and ill look when i get back

 

[Mechman60]

First stop flushing your removing all the buffering capacity of the soil. Second start feeding some available nutrients.your olants are hungry and overwatering prevents them from getting oxygen. Dont water on a schedule water when they need it. Judge by lifting the pots if your not sure then they aren’t ready.

Back the lights off to 50% for now.

Read this to understand watering.

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

Discuss different watering methods for growing your own weed from seeds. Our community members give helpful tips on how pot size and material, as well as environmental factors affect growing cannabis.

www.thcfarmer.com

Your good to know.

 

[KeytheCaregiver]

RO and Distilled water​

Ro and Distilled water is very low in mineral content containing carbonate or bicarbonate sources, we know this because if we test the ppm its usually under 40 and as low as 0ppm. This means it has a very low alkalinity (ability to neutralize acids) and is easily influenced by anything added that's acidic. But likewise it does not contain acid and is easily influenced by anything added that's basic. This results in a very unstable PH that can be easily influenced by anything added or anything its added to. In hydro the ideal ppm of carbonate/bicarbonate sources to provide an adequate buffer will be 50-100ppm with 75ppm being the target. Less than this and PH may swing to fast and be unstable, more and it will not drift enough and will require too much acid that could affect nutrient ratio's negatively depending on the acid used. By adding alkalinity and then acid we provide a more stable PH because adding more of either will have less impact on the overall ratio of acidic to basic elements

When used in hydro it should have alkalinity (a buffer) added back to prevent wild PH swings. Any source of carbonates, bicarbonates, silicates or hydroxides will work to create alkalinity. Sources i would recommend would be calcium carbonate, potassium bicarbonate (commonly sold as PH up) and finally what i would consider the best option is potassium silicate as it is a source of potassium and silica which are both excellent for cannabis. When using RO or distilled you will want to add back some calcium and magnesium if your nutrients are not designed for RO/distilled water as that's usually what Ro filters are removing for the majority. But most cal/mag is in the form of nitrate and provides no alkalinity (buffering capacity) so adding one of the previously mentioned or other is still a must.

When used in soil this unstable PH is actually IMO beneficial if you have a pre buffered soil (which you should) This means the water will have no impact on the PH potential (more on this later) of the soil and will almost instantly be influenced by the soil to the take on the PH of the soil makeup. This is why i feel we do not need to be PHing our nutrient solution for soil grows (unlike soiless and hydro). The soil is what will adjust the PH of our nutrient solution.

Marijuana pH Levels for Growing Weed: A Basic Explanation

In this article, we discuss proper pH levels for your weed plants; alkalinity, soil pH, tap water, and the effects of nutrients on pH when growing marijuana

www.thcfarmer.com

Soil PH potential​

Now when we buy a prebufferd soil like most of the ones we use they come "Prebuffered" (alkalinity adjusted) what does this mean? This means the company has added amendments that when water is added the resulting PH of the water in the soil will be in a favorable range for growing our plants. Often times peat is used to lower PH and lime is used to raise PH in these soils. Just like in water we want to control the alkalinity (buffering capacity) of the soil to have a stable PH that is not easily influenced by adding things such as nutrients or other. Unlike hydro and soiless where we control the alkalinity (buffering capacity) of the water by adding it directly to the water it is applied to the soil. Which brings me back to my point of we don't need to PH our nutrient solution in soil because the soil provides the buffering and will adjust the PH. Now things like lime and peat break down slowly over time and only soluble elements will impact PH so this is how they control the PH in soil over long periods of time, because it breaks down slowly and only a small amount is soluble at a time its unlikely after a grow it has been depleted. But if we are reusing the soil we should be looking at re amending the buffering capacity before using again to ensure there is enough to last through the next grow. Often times farmers will do this once a year before seeding crops.

We regularly add Powersi & Calmag to ensure their getting what they need.
However we have always pH'd the nutrient solution and water res to the 6.0 - 6.2 range and watering until runoff has been a rule of thumb for a long time for us.

Our soil mix is almost a 50/50 with Soil & Coco Coir/Perlite so it leans on the hydro side of the scale along with our 9 x 9 square plastic pots which learn towards the lower end of the perched water scale as far as I know from reading your posts.

Effects of nutrients and source water on PH​

First the PH down acids we use tend to break down much faster than the alkaline sources we use in both hydro and soil. For this reason we see a hydro systems PH generally rise over time unless something is creating more acid like decaying roots in which case we may actually see PH going down. Typically a PH increase of 0.2 in a 24 hr period is desirable and by adjusting the alkalinity we can control the PH drift. In the case of soil the acids used to bring PH down before feeding break down quickly and the alkaline and acidic buffer we have created minimizes the impact so they are really of not much benefit and have virtually no impact on long term PH potential of the soil. This is why we can't use them to lower high soil PH once we have an alkaline source buildup. However in hydro and coco PHing the nutrient solution is important because unlike soil there is not an adequate buffer established although in coco it is possible to do so.

Generally speaking the ratio's of nutrients we use will be acidic so when we get a buildup of nutrients we will almost always see PH drop. This is where you often hear ppl say flush the media. What this does is dilutes the dissolved elements and will remove some from the media in runoff.

Conversely a water source with high alkalinity can build up in the media and cause the PH potential of the soil to rise over time and in turn the PH of the water added to it. This is the reason we should look at the alkalinity of the water source not the PH as PH cannot measure the potential influence but rather only result.

Often in both circumstances its a good idea to flush the media to remove excess amount of available elements that may be affecting the PH negatively.

I'm not sure I understand how to look at the alkalinity of the water source and not the pH.

I check the PPM, EC, and pH of the tap water we have here on site at least before we installed our RO system. After that I still test EC, and pH before pH'ing the nutrient solution.

 

[Oldchucky]

And consider getting those plastic pots up off of the trays by an inch or two to get air circulation underneath also. And don’t be afraid to drill a few more drain holes in the bottom. Then you might have a chance of getting some decent Drainage. Just my two cents.

 

[Oldchucky]

If they were mine I would transplant them into cloth pots. Fear not the transplant!

 

[Aqua Man]

If they were mine I would transplant them into cloth pots. Fear not the transplant!

This ^^^ will help alot

 

[Aqua Man]

You not closer to hydro once you add soil the water table rises alot. Your soil with some added drainage. All the organics is soil will plug up the soaces that coco usually has

 

[Aqua Man]

Imo go soil or go coco mixing is a challenge. Water until you see runoff is fine if you have enough nutrients.

Throw the ppm meter to the wayside other than mixing nutrients.

Another concern is a lot of runoff all the time will deplete tge buffering capacity so you may want to continue ph adjusting if your going to continue the runoff. Although I recommend just a few drops run off and feed with a veg nutrient. No more bloom nutes as they don’t contain enough nitrogen

I inow it says bloom so that what they need right??? Wrong… they need what they need and in your situation they need a balanced nutrient solution.

 

[KeytheCaregiver]

If they were mine I would transplant them into cloth pots. Fear not the transplant!

We are in week 6 of 8/9. Also spent a decent amount of change on these pots. I've used cloth in the past and they were great, maybe for next season.

You not closer to hydro once you add soil the water table rises alot. Your soil with some added drainage. All the organics is soil will plug up the soaces that coco usually has

Imo go soil or go coco mixing is a challenge. Water until you see runoff is fine if you have enough nutrients.

Throw the ppm meter to the wayside other than mixing nutrients.

Another concern is a lot of runoff all the time will deplete tge buffering capacity so you may want to continue ph adjusting if your going to continue the runoff. Although I recommend just a few drops run off and feed with a veg nutrient. No more bloom nutes as they don’t contain enough nitrogen

I inow it says bloom so that what they need right??? Wrong… they need what they need and in your situation they need a balanced nutrient solution.

I agree, maybe I'll run 100% soil in one room and 100% coco in the other to find what works best for my setup.
I can see that, we've decided we have been over watering for a while now and are cutting down on our output. We are on week 6...you want me to swap to veg food? What would you recommend as far as balanced? Almost what we give them for their transition into flower? A little veg and some bloom?

 

[Aqua Man]

We are in week 6 of 8/9. Also spent a decent amount of change on these pots. I've used cloth in the past and they were great, maybe for next season.


I agree, maybe I'll run 100% soil in one room and 100% coco in the other to find what works best for my setup.
I can see that, we've decided we have been over watering for a while now and are cutting down on our output. We are on week 6...you want me to swap to veg food? What would you recommend as far as balanced? Almost what we give them for their transition into flower? A little veg and some bloom?

Yes exactly that transition nutes

 

[Aqua Man]

Let wm dry until they wilt…. Im betting like 3-5 days between watering

 

[Aqua Man]

Ince they get healthy they will drink more but go by lifting the pots. Again if you even wonder then its to soon…. You will absolutely know and be shocked how light they are in comparison

 

[sambapati]

Ince they get healthy they will drink more but go by lifting the pots. Again if you even wonder then its to soon…. You will absolutely know and be shocked how light they are in comparison

H20 man, this gauge works really well, and buckwheat groat water worked to help retain moisture....