Please Help,ph of run off high

grow medium half coco half perlite in 3gal smart pots,water every day with 2cups,get about half cup of runoff.Using distilled water with 2ml cal-mag ph to5.8 for first week of transplant,then use 2ml cal-mag and flora micro,and bloom at guarter strength also 1.5ml rapid start,and 2.5ml flora blend for a week,and my run off this morning ph7.0,have run a gal of distilled water with only 1ml cal-mag nothing else ph to 5.8 through plant and run off still at 7.0.ANY ADVISE!

check your pH meter

Check it with plain water before mixing and 6.4 everytime,ran gal of 5.8 through and still 7.0,maybe flush more,the young lady is a auto w.w. dont want to upset her she might not give me none!

That was my best guess, someone will weigh in with more ideas…
I don’t blame you not wanting to stress the auto!

Yeah,was thinking ph pen out of wack as well,but believe distilled water is right near the 6.4 I am getting.Do have calibration solution on the way.Strange that running a gal. of the ph5.8 water through the plant didnt change run off from 7.0 I poured the gallon through half chesked it 7.0 then theother half gallon and checked it and still 7.0,going to flush more through and see if I get a change.Thank you much for your input,and yeah I hear autos need perfection for best results.

Well as I said,run off was 7.0 flushed 1g of dastilled water with 1ml cal-mag ph to 5.8 and run off 7.0-flushed 1more gal through ph to 5.8 with no cal-mag and run off still 7.0-flushed another gal through no cal-mag phed to 5.8 and run off went up to 7.4 I dont know is this run off from coco normal,thats three gal fushed through and ph actualy went up.Right now I am stuck,and dont know what to do or think and am worried.

@MacGyverStoner and @latewood and @Donaldj need to look in

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Yes,their knowledge,and any other is needed.Seems like ph would have gone down.For now shes back in the tent,The plant looks fine,I just want to correct this asap if its a problem.

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I found a post where they talk about the ph of water, soil, and run off.

Hope that helps. Its backward from yours. In the topic his is low ph run off.

What type of coco coir are you using?

Some need to be thoroughly flushed before use.

If the coco is the type that is pre flushed, then it might also already have been treated with garden lime which would bring the pH up to closer to 7.0 in your run off and adding cal-mag would be redundant and this might be part of the problem, but it sounds strange for sure, it shouldn’t be going up.



Thanks JJ.chronic.clones,Ihave to run some errands will check those links soon as I get back!

Well Well,

The problem you are having when trying to flush is you are not flushing correctly. In order to flush a 3 gallon pot; You have to use at least 9 gallons of water.

The formula is Flush with 3 times the water as the capacity of your pot. :slight_smile:


Listen to these guys, they know. . . :grinning:
Thanks guys always :grinning:

Thank you everyone,I just got home,and macg I need to look back on details on coco purchaced,and I did not realize if coco not pre flushed need to do so,that may be problem.
Latewood I am going to flush six more gallons with distilled water ph5.8 until ph is down.Again thank you!

Wow! Flushed 9gal of water through plant and ph of runoff hasnt changed,it is 7.3 looked back on order details and the coco is kempf sold by WilliamKempfandsons.I called them and spoke to a guy about the coco,he said it is washed,but I dont know the guy had a heavy middle eastern accent,and it was hard to comunicate.The runoff water is very clear,and would think ph would have come down.This is only plant potted in cocoandperlite,others are in half soil-coco 7of them,only 2wks old and watered 3 times,I checked runoff on them last water,and 6.5 went in,and 6.5 ran out,going to water tomorrow,and hope runoff is good.Hope I havent ruined my chance for a succesful harvest I put alot in this,and am worried.All plants look very good so far,at 2 days shy of 2wks they are about 5in tall and maybe 9in wide 4nice sets of leaves,I hope they dont get ruined because of my ignorance,and damn coco from India.If problems start is there any thing I can flush with to remove impurities because 9gal of distilled water ph at 5.8 did nothing,runoff is clear though ha! ha! I have a small chunk of coco left going to soak it in phed water and aee what water reads tomorrow. Is going to be hard to sleep tonight,the plants look so good! Thank You All

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I know nothing about Coco coir except I’ve read that it seems to cause certain pH issues.

I use hydroton because it’s neutral and there’s no pH issues with it, but that’s just me, I like things simple cuz I’m kind of lazy

  • hope it works out for you!


I have noticed one thing that you are doing over and over again with you getting the same P H
Leave the Cal- Mag. out. Dont use it
And then do your test. I lbetr you get a better p H reading



Only used cal-mag in first gal of the nine,other eight gal just distilled water ph to 5.8,and nothing.Have to water my other seven that are in half F.F.-O.F.and half same coco as the one,and I will water enough to get runoff.Last water of those seven had runoff of 6.5

Before I tried to go to sleep lastnight,I soaked a piece of coco in distilled water ph5.8,checked after 7hrs ph6.4,also put sand at bottom,and top of pot when planted,it is desertsand for soil cover for house plants by MosserLee bought at my local just do it big chain store,used same 5.8water,and after about 7hrs ph7.3 I checked the runoff of last gal of flush runoff from lastnight it was 7.3 after 7hrs is 7.7

awe dude, it’ll be ok. Plants are alive and not showing signs then just be patient. If the roots didn’t like it they show you problems in the leaves. Let them recover from flushing.
Be patient :grinning: first soil i bought was not really soil, manure mix for yards. LOL