Can't fix this problem. Please help.

I've tried everything to correct this problem. I've maintained a solid PH level in my waterings, I've built an organic soil, and I don't overfeed the plants. They are showing some kind of deficiency. My initial diagnosis was Phosphorous deficiency, though I'm sure I added enough bat guano and kelp meal into my soil to prevent that.

Anyways, the plant is not showing signs of getting better. The lower growth is affected quite exclusively and the sickness is traveling up the plant.

I've watered with some medi-one and bloom formula to see if a phosphorous deficiency could be reversed. I think my other plants have responded well, but the Northern Light strain is continuing to show these brown spots and the lower leaves are drying up and falling off.

Any ideas?
The strain is Northern Light.
temps: 75-82
Humidity: 30%

What is the Ph of your soil? That really looks like Nitrogen toxicity, have you given any nitrogen chemicals? what brand of soil are you in what type of light are you using

Im guessing the ph of your soil is too high and there for its locking out the micro nutrients primarily cal mag

I agree with tpc_mikey , the leaves look awful dark like an N tox.
What are the NPK #'s on the bat guano label? Some bat guanos are for P and others are for N.

tpc_mikey said:

What is the Ph of your soil? That really looks like Nitrogen toxicity, have you given any nitrogen chemicals? what brand of soil are you in what type of light are you using

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After testing my PH, the run off was about 5.4.

I made my own soil. The soil composition is about 1/3 peat moss, 1/3 vermiculite and perlite, and 1/3 compost.

My compost mix is roughly made of Sheep, mushroom compost.
I added:

1/2 cup per cubic foot of soil mix of:

Blood meal (12-0-0)
Bone meal (4-10-0)
Worm castings ( a small handful per gallon)
Kelp meal (1-0.5-1.5)

1/4 cup of bat guano per cubic foot (0-8-1)...if I remember correctly.

And then some trace minerals (azomite).

A sprinkle of dolomite lime and epsom salt as well.

If it is N toxicity, the plants are not showing any of the claw at the moment, but they are showing signs of a lockout. I've corrected the PH to 6.5.

I let my organic mix cook for a month. If it is too rich in N, is there a way to correct this? I basically have 3 large tote bins full of organic mix.

not sure in organic mixes if theres a way the lime should buffer your ph and do hical lime next time and no need to add the epsom salt, can you take a picture of the plant out side of the grow lite ?

man theres a lot going on there

likely more than 1 issue making it hard do say with any certainty

don't think its N tox... the ph is low if it was in range your plants wouldnt take up as much N

you are showing some signs of magnesium issue but its hard to say if its from ph, lockout or def

i could be wrong its possible you might have a pest, maybe spider mites..its hard to say

your ph is very low so your mix needed more lime or and or some oyster shell

you could try using silica (like silica blast) to raise the ph or some ph up and a heavy flush with maybe ph 7.5 but it may take a while to get it up..im not sure!!

somebody with more soil experience might be have a better answer than me but my thought is to
rinse out some of the medium and re pot it in some store bought soil such as fox farm ocean forest or something like it

mugenius said:

After testing my PH, the run off was about 5.4.
.

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Do you mean you properly tested the soil PH and then also tested the run off?
The way you phrased the sentence, it sounds like the way you tested the PH is from the run off only. That is not the way to test soil PH. The results will not be reliable if you used run off to figure out the PH of the soil.









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mugenius said:

After testing my PH, the run off was about 5.4.

I made my own soil. The soil composition is about 1/3 peat moss, 1/3 vermiculite and perlite, and 1/3 compost.

My compost mix is roughly made of Sheep, mushroom compost.
I added:

1/2 cup per cubic foot of soil mix of:

Blood meal (12-0-0)
Bone meal (4-10-0)
Worm castings ( a small handful per gallon)
Kelp meal (1-0.5-1.5)

1/4 cup of bat guano per cubic foot (0-8-1)...if I remember correctly.

And then some trace minerals (azomite).

A sprinkle of dolomite lime and epsom salt as well.

If it is N toxicity, the plants are not showing any of the claw at the moment, but they are showing signs of a lockout. I've corrected the PH to 6.5.

I let my organic mix cook for a month. If it is too rich in N, is there a way to correct this? I basically have 3 large tote bins full of organic mix.

Click to expand...

First off, I would not use "mushroom" compost! Too much salt in mushroom compost!
I would have done 1/3 of Peat - EWC (worm castings) - perlite.
I would then add a cpl of gallons of (or lbs of, if your doing small amounts of finished soil) steer or cow manure.
1 cup of kelp meal
1 cup of a good organic tomato feed (dry mix)
4 cups of rock dust - granite rock dust
1/2 - rounded cup of Oyster shell (powdered) For your half a cubic ft of soil...

NEVER add Epsom directly to soil mix's!
Dolo has high Mg in it. if you feel you must use a Mg.....Use 1/2 dolo and 1/2 Oyster shell...
NEVER use hydrated lime!
I love garden gypsum - incorporate that!


Take a good read of this! You'll learn so much about building real organic soils!

https://forum.grasscity.com/threads/easy-organic-soil-mix-for-beginners.1116550/

pH will be an issue that you'll chase the whole grow! You didn't use enough!
That pH imbalance is most likely causing uptake problems.....pHing soil accurately, is a pain. The pH of run off is simply the pH of run off ant the near the pH of soil.
The dampness or moisture content of soil effects the pH in a big way...
Soil "self pH's". You put your plant in it, and the soil will work with the plant to stay in a happy pH value for that type of plant.....Now when you water a plant. the soil pH will drop around a whole point and as the soil dries back out,,,,it rises back to it's normal resting point......

"Real" accurate soil pH meters are very expensive......You don't "need" one! If you build your soil properly.....I don't ever pH my soil grows.....

mugenius said:

I let my organic mix cook for a month. If it is too rich in N, is there a way to correct this? I basically have 3 large tote bins full of organic mix.

Click to expand...

worm/compost periodically , peat moss vermiculite perlite would have been a beautiful finisher all by itself, without the other additives. I've done it, like rabbit crap, it just doesnt get better imo, but its poop

you could add more peat/perlite/vermiculite to your bins to buffer the strong mix? like those three bins added to seven more with only peat would no longer be hot aye?