Nutrient deficiencies and low ph runoff. Need help

noob4560

Active Member
okay so for alittle over a week now all four of my plants have been showing sings of nutrient deficiencies. when first noticed i fed the plants and growth shot up like crazy but the deficiencies seemed to progress. to me it looks like calcium and magnesium deficiencies so i added some azomite. next morning i checked on plants and noticed the top leaves were fading this dark brown color so i flushed the plants. while flushing i tested the runoff ph. ph going in was between 6.5 and 6.8. the runoff was around 5.3 to 5.1.
my plants are still getting worse what should i do i really need help with this one!!

soil- ffof (didnt feed until middle of week 4 and 5)
fertilizer- gaia green 2-8-4 and azomite
if any more info is needed just please say so.
 

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Renfro

Well-Known Member
ph going in was between 6.5 and 6.8. the runoff was around 5.3 to 5.1.
If the runoff comes out that low then the soil pH is likely much lower, like in the 4's for sure. I would want a quality soil pH meter like the Apera PH60S or the Bluelab Digital Soil Probe. This way you aren't guessing by runoff numbers as they will show the direction but not exactly how far you are off.

 

JSB99

Well-Known Member
okay so for alittle over a week now all four of my plants have been showing sings of nutrient deficiencies. when first noticed i fed the plants and growth shot up like crazy but the deficiencies seemed to progress. to me it looks like calcium and magnesium deficiencies so i added some azomite. next morning i checked on plants and noticed the top leaves were fading this dark brown color so i flushed the plants. while flushing i tested the runoff ph. ph going in was between 6.5 and 6.8. the runoff was around 5.3 to 5.1.
my plants are still getting worse what should i do i really need help with this one!!

soil- ffof (didnt feed until middle of week 4 and 5)
fertilizer- gaia green 2-8-4 and azomite
if any more info is needed just please say so.
A few things:
  • Your plants are stretching. This is either because your light isn't close enough to the canopy top, or it's not powerful enough (maybe even both).
  • Once your deficiencies are under control, you might think about topping those tall branches, or at least supercrop or bend them so they are level at the top.
  • After fixing, don't expect any damaged leaves to repair themselves. They won't. Instead, look at new growth to determine if your plants are happy.
And finally, don't stress too much over this. Your problems are easily fixable, and you're not going to find it dead by the day's end. :)
 

noob4560

Active Member
A few things:
  • Your plants are stretching. This is either because your light isn't close enough to the canopy top, or it's not powerful enough (maybe even both).
  • Once your deficiencies are under control, you might think about topping those tall branches, or at least supercrop or bend them so they are level at the top.
  • After fixing, don't expect any damaged leaves to repair themselves. They won't. Instead, look at new growth to determine if your plants are happy.
And finally, don't stress too much over this. Your problems are easily fixable, and you're not going to find it dead by the day's end. :)
i just lowered it back down it was at 2 ft away. im using a mars hydro ts1000 at 150 watts. its 15in away now. but i cant top or supercrop right now plus these are autos and they are starting to flower.
 

noob4560

Active Member
If the runoff comes out that low then the soil pH is likely much lower, like in the 4's for sure. I would want a quality soil pH meter like the Apera PH60S or the Bluelab Digital Soil Probe. This way you aren't guessing by runoff numbers as they will show the direction but not exactly how far you are off.

right now i dont have the cash for a soil probe but ill be getting one soon i promise you that hahaha. im thanking about top dressing the soil with some down to earth dolomite lime. does 1 TBS per gal of soil sound right??
 

Renfro

Well-Known Member
Ya, that's what I was thinking too.
Thing about the lime is it takes time and isn't an exact science. One may make an adjustment and not see positive results for several waterings, meanwhile more lime is added thinking it wasn't enough... Cannabis grows so fast we benefit from a much faster acting correction. With the method I suggested in the linked thread, correction is immediate and you see the results.

Even without the meter, based on his runoff I would make the assumption that the medium pH is below 5 for sure. If we assume it's just at 5 and lets say he's targeting 6.5 then he needs to do a corrective feed at 8.0 minimum. That may likely be an under correction but I feel it's a conservative bet with his run off numbers.
 

noob4560

Active Member
Did you read Renfro's thread? That should help a lot.
From the sounds of the lime he mentioned I don't think he did give it a read.
i just finished reading the thread. i have been watering with higher ph around 7.3 and not seeing a difference so far. so as you just said i will jump it to 8.0 and see how it goes. i wish i could get the hang of this stuff faster its frustrating but at the same time i enjoy it
 

PadawanWarrior

Well-Known Member
Thing about the lime is it takes time and isn't an exact science. One may make an adjustment and not see positive results for several waterings, meanwhile more lime is added thinking it wasn't enough... Cannabis grows so fast we benefit from a much faster acting correction. With the method I suggested in the linked thread, correction is immediate and you see the results.

Even without the meter, based on his runoff I would make the assumption that the medium pH is below 5 for sure. If we assume it's just at 5 and lets say he's targeting 6.5 then he needs to do a corrective feed at 8.0 minimum. That may likely be an under correction but I feel it's a conservative bet with his run off numbers.
That's exactly what I was thinking too. Awesome. Thanks for helping him. He sent me a PM last night, so I asked him to start a thread. When I woke up I saw you were the first to answer. I should have thought about that thread you made. That's awesome.

Can't wait for Sunday. Go Bucs, lol.
 

noob4560

Active Member
That's exactly what I was thinking too. Awesome. Thanks for helping him. He sent me a PM last night, so I asked him to start a thread. When I woke up I saw you were the first to answer. I should have thought about that thread you made. That's awesome.

Can't wait for Sunday. Go Bucs, lol.
BUCS!!! pandawan you get cooler with each post! lol thank you both seriously
 

JSB99

Well-Known Member
okay so for alittle over a week now all four of my plants have been showing sings of nutrient deficiencies. when first noticed i fed the plants and growth shot up like crazy but the deficiencies seemed to progress. to me it looks like calcium and magnesium deficiencies so i added some azomite. next morning i checked on plants and noticed the top leaves were fading this dark brown color so i flushed the plants. while flushing i tested the runoff ph. ph going in was between 6.5 and 6.8. the runoff was around 5.3 to 5.1.
my plants are still getting worse what should i do i really need help with this one!!

soil- ffof (didnt feed until middle of week 4 and 5)
fertilizer- gaia green 2-8-4 and azomite
if any more info is needed just please say so.
If you, or any other noobs weren't aware of why pH has to be within a certain range for plants to grow, its because different nutrients need different pH levels in order to be transported throughout the plant. If pH is out of a particular nutrient's range, that nutrient won't be absorbed by the roots, and it'll appear as a deficiency. Thats why if you know you're providing the right range of nutrients, but still showing deficiencies, its probably a pH issue.

soil-ph-chart-marijuana.jpg
 

JimmyJackCorn

Well-Known Member
If you're using tap water, make sure the water utility didn't recently spike it with chlorine/chloramine.

I suggest this because it seems a bit weird to me that you have these big nice plants that were okay for so long before this. I don't imagine they would suddenly start to realize that the soil has been really low pH all this time.

Has anything else potentially changed?
 

noob4560

Active Member
If you, or any other noobs weren't aware of why pH has to be within a certain range for plants to grow, its because different nutrients need different pH levels in order to be transported throughout the plant. If pH is out of a particular nutrient's range, that nutrient won't be absorbed by the roots, and it'll appear as a deficiency. Thats why if you know you're providing the right range of nutrients, but still showing deficiencies, its probably a pH issue.

View attachment 4817285
okay so that is something i didnt know. this is why i love it here! thank you again!!
 

noob4560

Active Member
If you're using tap water, make sure the water utility didn't recently spike it with chlorine/chloramine.

I suggest this because it seems a bit weird to me that you have these big nice plants that were okay for so long before this. I don't imagine they would suddenly start to realize that the soil has been really low pH all this time.

Has anything else potentially changed?
im using water from my well but no nothing has changed
 

JSB99

Well-Known Member
okay so that is something i didnt know. this is why i love it here! thank you again!!
I could be a little off when I said nutrients need to be in range for the roots to absorb them. It might just be that the roots can absorb them, but the plant can't transport the nutrients without the right pH level. Either way, that's ultimately what happens.
 
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