pH shift /organic soil grow/time for lime??

Delta9

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Im currently in about the 4th week of flower with 3 plants in soil
-my pH right throughout the grow until now has sat bang on at 6.5

3 or 4 days ago I noticed one plant in particular displaying lots of pale green leaves

then 2 days ago I fed my plants a compost tea and after then the pH has gone to 6.0 -which I realise is borderline..

So I really want to keep on top of this-and have researched a possible solution for using dolomite lime-but I am confused at what quantities to apply. I also understand it is a little slow acting, and that hydrated lime acts faster but seems generally not recommended.

Either way I don't want to sit on this too long without a fix and thereby lock out nutrients to my plants[and buds] at such a crucial phase..

What can I do?

I will put some pics up tomorrow in the light of day-my plants are sleeping right now..

Any suggestions in the meantime are very welcome.
 

Rosebud

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Are you in an organic soil now? If so, i grow organic and have never ph'd anything.

Looking forward to the pic's.
 
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Did you add lime to your mix originally? My understanding is that with organics you do not need to be concerned with watching/checking/adjusting your pH unless it is way out of whack because the soil feeds the plants. I am wondering if the light gredn is due to the fact that you are 1/2 way through flowering and they are getting N depleted?
 

Delta9

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Did you add lime to your mix originally? My understanding is that with organics you do not need to be concerned with watching/checking/adjusting your pH unless it is way out of whack because the soil feeds the plants. I am wondering if the light gredn is due to the fact that you are 1/2 way through flowering and they are getting N depleted?

THG I think you might have hit the nail on the head there- the more I read on the subject the more this points to exactly that issue - Light green new growth and yellowing of older fan leaves.
For some reason I expected that to happen later in the flowering period- like in the last couple of weeks of flower. And yes -I did add dolomite lime to my original pot mix - about 1 cup to 1m square from memory.

Sounds like Rosebud concurs with you too regarding not needing to worry too much about pH in soil- thats a completely new concept for me-so thanks for helping me understand that both of you!

My pH of 6.0 is still within an acceptable range then- so thats cool for now.
I understand that plants in flower require less N than in veg- and that too much N in flower can lock out other nutrients from being absorbed- so is it necessary to counteract the nitrogen deficiency at this stage?
 

ShOrTbUs

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what are you using to ph the soil? and have you ever added anything to adjust your ph during the grow?
 

shahomy

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hydrated lime acts faster but seems generally not recommended.
i just bought a 50lb bag of this stuff yesterday...looks like enough for about 50 years...why is it not recommended?
should i not use it?
 

Dman1234

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I dont know what hydrated is but I never put dirt in a pot without dolomite lime, also i sometimes give a good veg feeding (hi in N) a couple weeks into flower if i know its a 9 or 10 week flowering strain. jmo
 

Hushpuppy

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Hydrated lime is all calcium, you don't want to use that as it will cause lockout due to having too much calcium present. The dolomitic lime has a small amount of calcium but mostly Magnesium. You can get pulverized or powdered dolomite lime and mix it into the soil then water in (or you can mix it with water and add it the next time you water) as it sounds like the pH has dropped too low for organic (you want to be around 6.5-6.8) and possibly lacking in magnesium. How much you use depends on the amount of soil you have for each plant. How big are the pots you have your plants in?

I found that Espoma makes a lime that is micro pellet and is a nice mixture of calcium, magnesium, and a couple micro elements. It dissolves quickly in water and you can get it at Lowes/home depot/home garden stores.
 

Hushpuppy

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cool :) I just bought another bag of it for my new little grow that I just recently started :D
 

shahomy

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Hydrated lime is all calcium, you don't want to use that as it will cause lockout due to having too much calcium present. The dolomitic lime has a small amount of calcium but mostly Magnesium
So, dolomitic lime is different than hydrated lime? Both words are on the bag i bought...guess i`ll have to see if i can find a breakdown of what`s in it...

you don't want to use that as it will cause lockout due to having too much calcium present
Ugg... i already applied a spoon full last nite...top dressed and watered in on 5 gal. smart pots, medium is humboldt sphagnum peat moss...
 

pcduck

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Hydrated is baked lime.
Very fast reacting.
 

ShOrTbUs

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Isn't hydrated lime what they use to make concrete?
indeed it is. usually mixed with cement and sand. that stuff is nasty, use with caution. it will burn you, blind you, and can kill if you inhale too much.
 

Delta9

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what are you using to ph the soil? and have you ever added anything to adjust your ph during the grow?
I've never used anything to adjust my pH- I added dolomite lime to my pots when I originally planted my seedlings and nothing since then.
 

Delta9

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Hydrated lime is all calcium, you don't want to use that as it will cause lockout due to having too much calcium present. The dolomitic lime has a small amount of calcium but mostly Magnesium. You can get pulverized or powdered dolomite lime and mix it into the soil then water in (or you can mix it with water and add it the next time you water) as it sounds like the pH has dropped too low for organic (you want to be around 6.5-6.8) and possibly lacking in magnesium. How much you use depends on the amount of soil you have for each plant. How big are the pots you have your plants in?

I found that Espoma makes a lime that is micro pellet and is a nice mixture of calcium, magnesium, and a couple micro elements. It dissolves quickly in water and you can get it at Lowes/home depot/home garden stores.
Ok thanks Hush -thats interesting to know. I potted in 12 litre poly bags-but there is only probably about 9-10 litres of soil in there..
My original thought regarding the paler leaves was magnesium deficiency and I added Epsom salts when I last watered-that has'nt changed anything in the 5 days since. I think THG might have nailed the problem as Nitrogen deficiency-it's frustrating-I took a bunch of pics but the lighting doesn't really illustrate the issue very clearly. I'm gonna have to work the settings out on my camera.
 
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Delta9--I gave my early flowering girls a dose of blood meal today as I think I am having some N problems also. I have read that it breaks down fast and it is all N. I'll let you know if I experience any adverse effects.
 

Delta9

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Delta9--I gave my early flowering girls a dose of blood meal today as I think I am having some N problems also. I have read that it breaks down fast and it is all N. I'll let you know if I experience any adverse effects.
Thanks THG I appreciate that - I look forward to your results
-good luck :)
 

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