P deficiency?

visajoe1 · Apr 6, 2020

Three strains in the tent from seed, 5 girls, one is the issue. The other 4 in the tent are fine, including sister of same strain. They were all fed the same until this began to appear about 7 days ago. This one and her sister was fed twice 1 EC since this appeared and things seemed to stabilize for a few days, but I see today it has begun to progress further. Kinda looking like CA deficiency now too, but I know those work together and being in soil with .14 EC tap water and CA in nutes I dont think its likely. FFHF/FFOF w/added perlite

They were fed 7-9-4 with a dash of flower fuel (1-34-32), about 1/4th of 1/4 teaspoon, to up PK a smidge. Today they just got 6.5ph water because I cycle feed, feed, water.

Should I switch her to 3-12-9 and up the EC on next feed? Thoughts?

JWM2 · Apr 6, 2020

Magnesium deficiency. Add 1 tablespoon of epsom salt per gallon of water the next time you feed her.

visajoe1 · Apr 6, 2020

JWM2 said:
Magnesium deficiency. Add 1 tablespoon of epsom salt per gallon of water the next time you feed her.

Will do, thanks!

Dirtbag · Apr 7, 2020

Not to muddy the water, but that looks like spotting from Calcium deficiency to me.

visajoe1 · Apr 9, 2020

Dirtbag said:
Not to muddy the water, but that looks like spotting from Calcium deficiency to me.

I hear you, and that is what I want to think because it would be a simple fix. However, my experience is telling me otherwise and that there is no deficiency but rather an environmental cause that would make this one behave differently.

Or perhaps this flu thing has provided us all too much time? lol

Anyway, I'm zeroing in on VPD here because that is what determines plants metabolism, transpiration, stomata activity, nute uptake, etc. High VPD can cause leaf burn even with a .8ec feed for instance, simply because she wants more water than nutrients, and she cant transpire nutes out properly and it gets stuck in leaf. Burning it.

So, I lasered all my girls to calculate individual VPD and bingo! Now I see why the leaves are burning. I need to maintain a lower VPD still. Perhaps that particular strain needs a low VPD throughout.

VPD #'s
This strain- 1.3-1.5 (75/76 leaf temps)
Strain #2- 1.1-1.2 (73/74 leaf temps)
Strain #3- .92 (71 leaf temp)

Tent temp 77
Tent humidity 53

Jimster · Apr 9, 2020

Calcium issues are frequently the result of the Phosphorus-Calcium interaction. FFarms already has a bunch of nutes in it. Adding P and K upsets the balance, with the phosphorus reacting with the calcium to make Calcium Phosphate, a mineral called Apatite and it binds the calcium, making it unavailable to the plant. Epsom salts might help, but a foliar application of it would bypass any lockouts in the roots and giving a quick burst of Mg.
A flush might help (make sure to give a nitrogen snack after snacks since Nitrogen is the most easily leached nute, phosphorus is the most difficult and persistent) but probably won't remove much of the phosphorus. Keep your Ph below 6.5 to facilitate absorption of nutes by your plants and make sure they are getting enough calcium and magnesium to overcome any lockouts. Keep in mind that a lot of Cal-Mag can also cause issues with high Ph, and in soils that have a lot of phosphorus, it can bind with it and throw off everything. FWIW, I find that keeping nute levels low helps me to avoid lockouts and similar issues. Sometimes you will get a plant that is just picky and doesn't like a lot of nutes, so it has become my mantra to use the minimal amount of nutrients and stuff as possible. I'm not saying not to use them... I am saying to use them with restraint. Plants rarely have deficiencies in a well balanced soil and it isn't until we try to supercharge the growing process that you start having problems.

cemchris · Apr 10, 2020

Ca def will only be at the top/new growth of the plant FWIW

visajoe1 · Apr 13, 2020

it appears this is just a genetic pos plant. everything else is fine in the tent, except this bitch. shes just angry no matter what happens.

pretty sure its actually a K deficiency, but even after adding more K yesterday it got incredibly worse overnight. leaves are dry like sandpaper, stems feel like rubber. just give 6.5ph water and she continues to deteriorate.

this cunt is going in the trash if not turned around by Friday, tired of looking at her hideous face.

76 degrees, 54% humidity. her leaf temps never go below 75.

visajoe1 · Apr 13, 2020

last night at lights out. this morning its much worse, several leaves are curled up now and crunchy, i'll post another pic tonight of this hooker

Beachwalker · Apr 13, 2020

With agree with the K, did you take a slurry test yet?

I would keep the PK booster for very late flower if at all, that could possibly be related to the issue?

visajoe1 · Apr 13, 2020

Beachwalker said:
With agree with the K, did you take a slurry test yet?

I would keep the PK booster for very late flower if at all, that could possibly be related to the issue?

I have not done slurry, but i did check ec of runoff today out of curiosity, i havent done that in years. it was only .6, so that seemed fine. i feed .7-1ec, but usually leaning on low end.

agree pk booster may be contributing to the issue in my attempt to quick fix, so i just flushed her with bloom feed this morning (3-12-9) at .7ec.

Beachwalker · Apr 13, 2020

I feed the same balanced NPK ratio the whole way through, I only adjust the PPM. I don't believe in PK boosters and I definitely wouldn't use them or a bloom feed that early in bloom, plants yellow too soon when you drop the nitrogen too quick, good luck!

visajoe1 · Apr 13, 2020

Beachwalker said:
I feed the same balanced NPK ratio the whole way through, I only adjust the PPM. I don't believe in PK boosters and I definitely wouldn't use them or a bloom feed that early in bloom, plants yellow too soon when you drop the nitrogen too quick, good luck!

what npk do you feed

Dirtbag · Apr 13, 2020

I agree with Beachwalker. I'd feed her a roughly 3-2-4 ratio at around 1.3-1.4ec for a plant that size.

Beachwalker · Apr 13, 2020

visajoe1 said:
what npk do you feed

Honestly imo it matters more if it's a balanced ratio; I sometimes use a 20-20-20 in bloom, but right now I'm using it in veg, and I'm using Master Blend in bloom; it's more about having an optimally balanced NPK ratio, and adjusting the PPM

Edit: I add things like mykos, tm7 & what have you, but I use a balanced fertilizer from start to finish

Hidd3nGr0w · Apr 13, 2020

Doesn't this look like a P excess instead of some kind of def?

Or is that what you were getting at recommending the balanced nutes @Beachwalker and @Dirtbag?

visajoe1 · Apr 13, 2020

right at lights out. gave a .2ec foliar of grow (7-9-5) 10 minutes prior.

@Hidd3nGr0w i saw your post as im writing this, and these pics at link below do look identical to mine.
i'll flush em with ph water tomorrow

Phosphorus Excess in Cannabis Plants, Get it Fixed, Quick! - Percys Grow Room

Phosphorus excess in cannabis plants is a rare problem. Do you have phosphorus excess in your plants? Find out here and get it fixed!

percysgrowroom.com

Hidd3nGr0w · Apr 14, 2020

visajoe1 said:
right at lights out. gave a .2ec foliar of grow (7-9-5) 10 minutes prior.

@Hidd3nGr0w i saw your post as im writing this, and these pics at link below do look identical to mine.
i'll flush em with ph water tomorrow

Phosphorus Excess in Cannabis Plants, Get it Fixed, Quick! - Percys Grow Room

Phosphorus excess in cannabis plants is a rare problem. Do you have phosphorus excess in your plants? Find out here and get it fixed!

percysgrowroom.com

Wasn't going to say anything, till I noticed a few really thin fan leaf's pop out here and there in the pic. Still taking awhile for it to sink in, with me being hardheaded and all, that every issue isn't cal/mag or deficiency. But that's me!

Hope your diagnosis and fix gets it turned around quick!

Dirtbag · Apr 14, 2020

Hidd3nGr0w said:
Doesn't this look like a P excess instead of some kind of def?

Or is that what you were getting at recommending the balanced nutes @Beachwalker and @Dirtbag?

Exactly what I was getting at. Feeding all those high P ferts is a bad idea.

Jimster · Apr 14, 2020

Hidd3nGr0w said:
Doesn't this look like a P excess instead of some kind of def?

Or is that what you were getting at recommending the balanced nutes @Beachwalker and @Dirtbag?

A P excess can cause Ca and K deficiencies. When you have a lot of phosphorus and calcium together, it create Calcium Phosphate, which is a mineral that isn't useful to plants. The two chemicals, P and Ca, can combine together if in excess and cause deficiencies for both when they get locked up in the mineral called Apatite.

P deficiency?

P deficiency?

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P deficiency?

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