How to correct ph issues

[aeviaanah]

I have been adjusting ph to 6.0 in soil lately! I dont believe it. I am a pretty established grower and I guess i mixed up hydro ph with soil. Looks like i may have been locking out magnesium and calcium. I have been feeding calmag but with pH in this range may have locked it out. I do show symptoms of magnesium lockout but not evidence of calcium lockout.

I am week 3 of flower and plants do look real healthy in some spots and show signs of mag lockout in others. Any advice to the best way to rid of possible build up of salts or cal/mag in the soil? How would an advanced grower attack this situation?

I can think of two ways that might be beneficial...

1. Water 1-2 times with plain ph balanced water (6.5) continue as is at this ph.

2. Bring all plants to bathtub and flush with ph balanced water (6.5) and feed.

 

[jawbrodt]

Flushing, is the best way to go, as you might've guessed?lol But, if you can't do that, add some powdered lime to your 6.5 water(PH before adding the lime)(about 2 TBSP per gallon) and water heavily. Since your PH isn't terribly outta-whack, that should do the trick. Also, since you think you may have salt build-up, either go with the flush, or water really heavily, until you get a bunch of runoff. It won't be an actual "flushing", but will certainly help.

 

[aeviaanah]

right on thankyou..

 

[Serapis]

right on thankyou..

Be careful with the lime, you can over correct and have issues keeping soil PH below 7.0 I'd get my runoff ph to 6.0-6.5 before I worried about adding more to them. Any PH under 6.5 in the soil is going to induce MAG lock out. I would def flush. Run a gallon through and get the ph read on the end of the run off. adjust 2nd-5 gallons ph to reach desired run off. You can try to foilar feed Epsom salts and water and see how the plant reacts before adding lime. If it reacts well, top dress lightly with pelleted lime.

 

[SouthernWeed]

Disolve one tablespoon of dolomite lime (available at any garden supply/home improvement center) per gallon of water and flush with 3 times the volume of your planter.

You didn't mention the size of your planters or the strain, but if they are 3 gallons or less, you may have completely used up the soil, in which case the PH will continue to drop back into the high 5's to 6 and you'll have continual lock out problems. A complete flushing and careful transplanting (after completely drying out) into a larger planter may be required to keep things running in range. Mid to late flower is an awful time to have to do it, but it may have to be done.

An extremely easy way to solve a Mag problem is to use disolved epsom salts, at the rate of 1/2 teaspoon per gallon of water, on your water only days. Often, I've found that adding epsom salts completely resolved both sides of a Cal/Mag issue...lime breaks down into calcium as well, so if you flush out with lime water, you'll be heading in the right direction.

Hope it helps you out.

 

[aeviaanah]

i use cal mag...i think i will just flush with ph balanced water until runoff reaches 6.5...i will then water using calmag...how does this sound?

 

[jawbrodt]

^I think that'll work fine. You're well into flowering, and your PH isn't that bad, so I'd say "go for it".

 

[SouthernWeed]

i use cal mag...i think i will just flush with ph balanced water until runoff reaches 6.5...i will then water using calmag...how does this sound?

You can pour cal/mag on it until the cows come home, but if you're locked out it'll do you no good. If memory serves correct cal starts locking out at 6.1 in soil...mag locks out a little lower...about 5.9...so if your soil is borderline/used up you may get runoff up to 6.5, but it'll never stay there and the lockout issue will reoccur...within a feeding or two.

 

[aeviaanah]

You can pour cal/mag on it until the cows come home, but if you're locked out it'll do you no good. If memory serves correct cal starts locking out at 6.1 in soil...mag locks out a little lower...about 5.9...so if your soil is borderline/used up you may get runoff up to 6.5, but it'll never stay there and the lockout issue will reoccur...within a feeding or two.

i dont quite understand what you mean by used up. do you mean used up as far as calcium/magnesium? or used up as no longer able to buffer? i do agree that if you are locked out you are locked out. but if one would flush the salts and begin watering with proper phd water wouldnt this fix the lockout? adding calmag would then fix the deficiency correct?

 

[SouthernWeed]

i dont quite understand what you mean by used up. do you mean used up as far as calcium/magnesium? or used up as no longer able to buffer? i do agree that if you are locked out you are locked out. but if one would flush the salts and begin watering with proper phd water wouldnt this fix the lockout? adding calmag would then fix the deficiency correct?

Sorry, I was not clear at all on that. All commercially available soil is PH buffered with varying amounts of lime...some more, some less. Once this lime has been used up, soil PH will drop quickly and continually. If this is in fact the case, the addition of 2 Tablespoons of dry pelletized dolomite lime per gallon of planter size, added 5-6 weeks into the grow and worked into the soil with a claw, will assist greatly with keeping PH steady through the latter portion of the grow. Caution must be used not to over apply pelletized lime, as a heavy dose can over calcify the soil and cause problems with nutrient uptake, especially Phos., which is critical for flower formation. 2 Tablespoons per gallon is widely recognized as the appropriate dosage, and I've never had an issue using that amount.

Once the PH problem has been resolved, the addition of cal/mag will clear the problem right up, but you have to get it under control first or you're just wasting money on the cal/mag.

Hope that clarifies things a bit.

 

[aeviaanah]

I have never added any lime to this soil. What if soil is not 'used up' will the addition of lime harm the plants? Not sure how to tell if soil is used up. Should i test runoff water? Is runoff testing an accurate way of testing soil ph?

 

[Serapis]

If you have a Ph meter, measure the PH of the fresh water and record it. For example, my rain water is 7.2 ph When I water a plant with that, the soil will increase or lower my water's PH as it runs through the soil, depending on whether it is acidity or alkaline. If the run off were to measure for example 5.5, that would indicate my soil is extremely acidic and needs to have the PH raised. If my run off had been say 8.0, then I know that I need to use PH down on my fresh water to reduce the PH in my soil. (just examples, you can also adjust PH with some ferts that make soil go up or down, it's a learning process)

I have my plants numbered and I record run off each plain watering. I also have a battery operated soil tester that while not as accurate as my PH meter from Milwaukee, comes close. I try to do my ph adjustments on non feed watering days, because I just don't have the experience of adjusting and feeding at the same time yet.

To answer your question, run off gives you an idea where your soil is at. If your water is 6.5 and the run off is 6.5 then your soil is near neutral 7.0 If you pour in 6.5 ph water and get back a lower or higher ph, the soil is off accordingly. in most cases, you'll find that you'll have to use PH down with soils, but near end of soil life, you may need to adjust up. The improtant thing is to know the ph of your water and adjust accordingly to bring your soil in line. Ideal soil is 6.5 -7 Under 6.0 and some nutrients get locked out. Over 7.5 and you lose some others....

I hope this helps rather than confuses.

 

[aeviaanah]

this is a great help thanks. i just watered 6.5 and runoff was 6.5. which tells me i should be ok? i wonder why i am getting magnesium lockout symptoms? i just noticed a bunch of caterpillar looking larvae in the runoff water. anyone know what this is? i may flush with permethrin now.

 

[Serapis]

Plant's PH is fine then, keep monitoring.... as for larvae in run off, that can't be good. I'm not sure caterpillars lay eggs in soil as opposed to in sacks or webs on leaves and stems. Got any pics of that runoff?

 

[doc111]

this is a great help thanks. i just watered 6.5 and runoff was 6.5. which tells me i should be ok? i wonder why i am getting magnesium lockout symptoms? i just noticed a bunch of caterpillar looking larvae in the runoff water. anyone know what this is? i may flush with permethrin now.

Probably fungus gnat larvae.

 

[allnaturalgrow.com]

I would use this liquid lime that is sold by aggrand it always brings my ph down and down quick, being in the liquid formula it can work faster,
check it out at allnaturalgrow.com, its like $11.00 shipped

I have been adjusting ph to 6.0 in soil lately! I dont believe it. I am a pretty established grower and I guess i mixed up hydro ph with soil. Looks like i may have been locking out magnesium and calcium. I have been feeding calmag but with pH in this range may have locked it out. I do show symptoms of magnesium lockout but not evidence of calcium lockout.

I am week 3 of flower and plants do look real healthy in some spots and show signs of mag lockout in others. Any advice to the best way to rid of possible build up of salts or cal/mag in the soil? How would an advanced grower attack this situation?

I can think of two ways that might be beneficial...

1. Water 1-2 times with plain ph balanced water (6.5) continue as is at this ph.

2. Bring all plants to bathtub and flush with ph balanced water (6.5) and feed.

 

[aeviaanah]

would u use this even tho ph of runoff is testing fine? this late in flower also.

 

[doc111]

would u use this even tho ph of runoff is testing fine? this late in flower also.

Testing runoff isn't the most accurate way to test soil pH. What kind of soil are you using? I'm pretty sure those are fungus gnat larvae. Not that big of a deal but if you want to you can get some mosquito dunks and put on in your water over night before watering. They use a beneficial type of bacteria that kills mosquitoes and fungus gnats.

 

[aeviaanah]

are you sure all are safe for marijuana plants? arent these usually used for pools and standing water? i couldnt find an image that was closely related to the fungus gnat, and i havent seen any flying gnats around.

 

[doc111]

are you sure all are safe for marijuana plants? arent these usually used for pools and standing water? i couldnt find an image that was closely related to the fungus gnat, and i havent seen any flying gnats around.

I've been using mosquito dunks for over a year now with no ill effects. They are usually used for standing water but you can crush them up and add them to your water or I take a half a dunk and put it in a container of water the night before I water. They don't get rid of all of the gnats but it cut the population down dramatically. What kind of soil are you using?