High ph runoff in soil less medium!

Hey guys, I have run into a bit of a problem with my runoff. Or so I think it is a problem but have read contradicting evidence about this subject.

I have got 3 seedlings...1 is 4 weeks old and growing like a runt so almost ready to toss it and I have 2 others which are 2 and a half weeks old growing healthy as hell at the moment.

I have a mix of about 35% perlite and 75% peat moss with a little bit of dolomite lime(about 3/4 tbl spoon per gallon). After reading that and later researching some people do and some dont. Before mixing I read that peat moss is quite acidic and should mix 1tbl spoon per gallon. I have gone about my grow and just started feeding nutes on friday giving about 1/3 strength for first feed.

Ph for watering now is about 5.5 before watering and runoff ends up at 7.5 or so. I have read that alot of people dont worry about runoff too much in coco and peat until the plant actually starts showing deficiencies but I just dont want this to come back and bite me later.

Before friday I was just feeding straight distilled water...no ph'ing water or runoff as didnt have a ph meter and wasnt giving nutes.

Can anyone give me a rundown on why the runoff is so high? Is it the dolomite lime acting like a buffer keeping it at a specific ph? Is there a way to resolve this like lowering my ph before watering even more?

I have just done a bit more reading and alot of people mention treating coco like hydro and not really worrying about the runoff...They mention coco but isnt peat moss similar to coco. Should I be worrying about this high runoff issue or just worry about it if a problem arises?

Over 90 views and noone got any info on runoff in soilless mediums?

I have had high ph run off in the past with pro mix. I don't remember any serious problems that I could attribute to the high ph. I did quit using lime though to try and keep the ph lower but I rarely check it when they are looking good. I don't know if this is helpful or not. I think your ph may go down after a few weeks of feedings anyway. Good luck.

Did you soak your mixture in ph adjusted water before you put your plants in? Or did you expect your medium to be the right PH out of the bag.

70's natureboy said:

I have had high ph run off in the past with pro mix. I don't remember any serious problems that I could attribute to the high ph. I did quit using lime though to try and keep the ph lower but I rarely check it when they are looking good. I don't know if this is helpful or not. I think your ph may go down after a few weeks of feedings anyway. Good luck.

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It is helpful as it just confirms that alot of people using a soilless mix dont really worry about runoff unless a problem starts showing

Kervork said:

Did you soak your mixture in ph adjusted water before you put your plants in? Or did you expect your medium to be the right PH out of the bag.

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No I didnt expect it to be perfect from the start. I did however read over and over that 1 tbl spoon of lime per cubic sq foot of peat would bring it up to a reasonible ph as straight peat moss comes out quite acidic from the bag. Through all my reasearch I never read to soak a medium in ph adjusted water. I read to flush, read to add lime but not soak it...

Anyone else got any input for high runoff in a soilless medium?

yer bro don't even worry or stress about your run off.....and don't take in to much on what u read.....u kno all the fancy shit what ever .best way to gro is by reading your plants.....what nuts are u using?

imcjayt said:

yer bro don't even worry or stress about your run off.....and don't take in to much on what u read.....u kno all the fancy shit what ever .best way to gro is by reading your plants.....what nuts are u using?

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Im using GH Flora series. First feed was at 1/3 strength on Friday and that when I took the reading...I was like wtf cos it went in at 5.5 then I figured I mustve fucked up by putting the dolomite lime in but I had read so many place that I should as peat moss alone has a ph of around 4. Then I read that most dont even ph the runoff as with soilless it can be quite misleading...

The lime does act as a buffer but Im not sure of the range it keeps the medium in. (I believe around 7?)

Im running promix which is similar to what your running. I had a heck of a time with ph
because I didn't know where to keep it. I have since found that around 6 - 6.2 has been
working well. All of the reading I did pointed toward low 6's.

Using the GH nutes I had troubles with the PH fluctuating. I suffered defs and had a heck
of a time getting it to stabilize.

I switched nutes to DynaGro and flushed the plants with a 1/4 strength solution ph'd to 6.2
and after about a week now they are looking better.

I was reading that most people don't ph their runoff either, but they seem to when problems
set in, then they flush to get it back into range.

Hopefully this helps a bit.

ricky1lung said:

The lime does act as a buffer but Im not sure of the range it keeps the medium in. (I believe around 7?)

Im running promix which is similar to what your running. I had a heck of a time with ph
because I didn't know where to keep it. I have since found that around 6 - 6.2 has been
working well. All of the reading I did pointed toward low 6's.

Using the GH nutes I had troubles with the PH fluctuating. I suffered defs and had a heck
of a time getting it to stabilize.

I switched nutes to DynaGro and flushed the plants with a 1/4 strength solution ph'd to 6.2
and after about a week now they are looking better.

I was reading that most people don't ph their runoff either, but they seem to when problems
set in, then they flush to get it back into range.

Hopefully this helps a bit.

Click to expand...

Yeh, I might just stop worrying about it until a problem does pop up. Im feeding at 5.5 hoping that it will lower it somewhat

This is why I like PROMIX...pH balanced. I wouldn't use lime..Promix and a lil extra perlite makes it so easy.

In my last two grows (when I first started to use promix) I have had the same very high pH runoff. I use reverse osmosis water, at first straight out of the filter, then after I discovered the high pH, adjusted down using vinegar to various levels to try to combat the high pH. The RO water is always supplemented with 5ml CalMg+ per gal, and I use GH flora 3 part nutrients "bunzboy's feeding schedule".

I am experiencing major plant problems that I have to believe are caused by the pH imbalance. Next grow I'm going to switch to regular potting soil, which from what I read buffers pH better.

micro987 said:

In my last two grows (when I first started to use promix) I have had the same very high pH runoff. I use reverse osmosis water, at first straight out of the filter, then after I discovered the high pH, adjusted down using vinegar to various levels to try to combat the high pH. The RO water is always supplemented with 5ml CalMg+ per gal, and I use GH flora 3 part nutrients "bunzboy's feeding schedule".

I am experiencing major plant problems that I have to believe are caused by the pH imbalance. Next grow I'm going to switch to regular potting soil, which from what I read buffers pH better.

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Im not sure cos im from Australia but isnt promix peat moss based, meaning it would be a soilless grow. That bunzboys feeding schedule is for soil grows, not soilless...

In all honesty...PROMIX is dummy proof. You can't fuck it up. Tap water, DNF nutes, and no pH balancing necessary. When Dnf nutes are added to tap water it puts it right at 6.5...where it should be for soil/soiless. I have never known anyone who checks the runoff...no need IMO. Keep it simple...PROMIX all the way!

Here's the first couple of sentences from the feeding schedule. I had assumed the super soil talked about was also a peat based medium like promix sense they talk about it being semi-soilless and containing no nutrients. But that may have been a false assumption.

This feeding schedule will help you on your new adventure of growing high quality marijuana. These ratios are based on a medium consisting of a semi-soilless mix of 1/3 Super Soil (a generic soil brand from Home Depot), 1/3 perlite & 1/3 vermiculite. Supersoil contains no nutrients, so if using a different brand w/ nutrients adjust your fert amounts accordingly.

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If that's the case, can anyone share a feeding schedule for GH flora that would work better for a peat based soilless mix?

And as far as promix being dummy proof, well, I'm glad you are having so much success. Although I am certainly a novice (less than 1 year at it and only a couple plants at a time) I don't consider myself a dummy and I am having quite a set of problems. I don't know what exactly is causing my problems, but saying if you use promix you will not have pH problems simply is not true.