ph problem in soil

[HellUvaHigh]

Hey guys ive recently been having problems with the ph in my soil grow. No matter what i water at the run off ph is always at 6. Ive been trying for two weeks to get it back on track but it just wont stabilize and its killing my crop. Im using Fox farm ocean forest and water from the tap sitting out 48 hours. An feedback would be great.

Rich

 

[buster8813]

what is the water ph'ed to? Im no expert with handling pH so ill leave that for someone who can give more solid advice but im quite certain you should say what the water is going in with and without your nutes

 

[pSi007]

If you are using anything with Ammonia Sulfate in it, it will lower the pH. Get rid of it and use something without it, flush at 1/4 strength - pH 7.

If you are using organic powders and teas, flush with pH 7 - pure water/tap water.


After flushing, let the medium dry for a week or so.

 

[mr tweeks]

Personly i never worry about ph in soil the soil usally buffers it out

 

[pSi007]

Personly i never worry about ph in soil the soil usally buffers it out

I have heard of people complaining about Fox Farm Ocean Forrest. I guess it is too dense and needs perlite, it also is very organic and acidic.. I would re-medium all of it, put in perlite and 1/4tsp of dolomite lime per 2 gallons of medium. mix it well.. This should stabilize the FoxFarm stuff.. BTW, I think the expensive potting soil is junk..

Don't let anyone tell you a run-off of 6.0pH or lower is perfectly fine.. They grow shitty/small flowers, all the leaves turn yellow and fall off, and they are only using a VERY small portion of their medium if that's what they choose to do. My run-off looks like black tea and is perfect at 6.4pH out, 6.8pH in. My roots form a perfect ball in the medium and fill the medium with 100% white roots. (none of this brown shit, which is what pH 6.0 will do to your roots.) Also, make sure your roots dry out a little after you flush. If your pH is holding at 6.0 or less, you have a high PPM of fert run-off AND your soil is constantly wet, your plants will be REAL FUCKED UP.. real fast...

..make sure your plants can survive a flush.. 6.0pH or less is nasty in soil.

Bottom line: Organics will decompose to acids, it is best to use an aerator (Perlite) + a dash of Dolomite lime. Be careful with the lime, it is not useful unless you mix it well into the soil BEFORE you put the plants in it.. BUT, it will stabilize the decomposing organics very well..

 

[Wetdog]

If you want it simple, here it is.

Go to HD or Lowes and get a 40lb bag of Dolomite lime, a whopping $4.50. Or, Calcitic lime, a bit more @~$15 for the 40lb bag. Just NOT hydrated lime.

Add 2tbl/gallon of mix, or 1cup/cf of mix. Scratch into the surface if a plant is there, but better added to the mix before use. Not sure what the 1/4tsp/2 gallons is supposed to do (from above). Not much, I'm sure. Give it a couple of weeks to get working well.

This is nothing but ground up limestone rock and is not going to burn or harm anything. It will correct your low pH though and supply Calcium and Mag to boot. I've grown things in crushed limestone. Drainage sucked, but nothing got burnt.

I haven't used my pH meter in well over 2 years and haven't pHed anything going in (water, nutes, teas, whatever), in close to 4 years. No need with a well limed soil.

You can do it the simple way by adding lime, or the hard way by pHing everything. Which still doesn't work as you've noticed. The soil will buffer whatever's added to the soils pH, but the pH of whatever's added has at best only a temporary effect of the soils pH.

Wet

 

[SpicySativa]

A pH of 6 in soilless mix absolutely WILL NOT kill your plant (it's well within range for organic soil). What WILL kill your plants is trying frantically to fix a pH of 6.

 

[max420thc]

A pH of 6 in soilless mix absolutely WILL NOT kill your plant (it's well within range for organic soil). What WILL kill your plants is trying frantically to fix a pH of 6.

a ph of 6 will not kill your plants.But he is pouring in water with a ph of 7 and it is lowering it to six on the run off and that means his PH is lower than 6
Always add garden lime=the term they will know at lowes or mennards. They will be clueless if you ask cor dolomite lime.
No matter how good you think the soil is you are using..lime the shit out of it.Some will tell you it will harm the plant if you use to much.Lime is high in calcium and is good for the plant it maintains the soils PH.Everyone is steering you in the right direction with the lime.Without doubt you should always start the grow with the lime mixed into the soil to begin with.
Ive seen and done some really screwed up grows because of PH being off.Top dress the soil and add lime to a FLUSH..and flush it through the dirt.2 TO 1..if you have 1 gallon of dirt use two gallons of PH balanced water with lime added.This is not going to save your plant from stress or lower production.
A marijuana plant moves so fast if it is not run (preferably to perfection)anything at all is going to effect the production and quality.There just isnt enough time for it to recover before it finish's.

soil you want to be around 7 for a ph..in hydro it is around 6

 

[pSi007]

careful with the dolomite lime, 2tsp per gallon is too much. It has a pH of 8 and it WILL base out your medium BUT it is not very mobile in water and the plant will need to use most of it up, or else it will stay in the soil and make it really alky.

The smaller amount I suggested has worked perfect for my blood, bone, guano, seaweed meals. It keeps the pH at a perfect 6.6 or so. But yea, if his runoff is 6 or lower, he is not using all of his medium. Some of those roots are turning brown and shitty if they sit in a constantly moist medium.

 

[Wetdog]

The pH of dolomite is 7.0.

Beg to differ about over doing it since I've grown stuff in straight crushed limestone and it's hard to get over 100%.

How many years have you actually used lime? All this sounds more like internet mis-information than actual experience.

I've been using lime since ~1973 or so and my experience with it just doesn't agree with your information.

YMMV

Wet

 

[pSi007]

It has many forms of carbonate in it, a neutral 7 is perfect. thanks WD..


...I hydrate my dolomite lime with organic acids, this will spike the pH to alkaline. When you add acids to the dolomite, it should change the pH to alkaline. weird, i know.. ..This is how I can use a 30-gallon pot, pH 6.8 in, 6.4 out..

I believe if you add acids to dolomite lime, it will change it to hydrated lime. I could be wrong.. too much lime seems to chalk up my soil real bad and cause some really wild pH shifts.

 

[Wetdog]

I *had* a monograph on how hydrated lime is created years ago, but have no idea where it is now. Basically, it is treated (acids?), and then cooked in a kiln. It's great for farmers who need a temporary pH adjustment without having to plow it in since it is very soluble.

The only thing I've noticed from too much lime, or any rock dust for that matter, is that it will screw with your drainage. But, never noticed any pH problems. My peat based mix (I make my own), usually hovers around 6.8 or so.

I don't check the pH of anything going in, or the run off. If the plants look happy, I'm happy and don't take it any further.

Wet

 

[Gquebed]

Geezeuz... run-off pH means nothing. If you're using sterilized peat (Promix, Sunshine) mixed with perl and verm then the only thing that matters is what's going in.