PH to high in my coco ( runoff )

Hello im having trouble with the ph, i think my plants are having nutrient deficiency related to the ph being to high in my rootzone i was usually watering with PH 6.3 and TDS of 900ppm.
My medium is 50%coco 30%perlite 20%wormcastings.

Temp and RH
Lights on is 27C 50-60%
Lights off is 21C 50-60%

Then i noticed the deficiency so i testet my runoff.
I watered with ph5.9 and 900ppm the runoff was 6.6 and 1900ppm.

In order to lower both PH and PPM i stardet to water with lower PH and no nutes.

I watered 3 times since then here are the outcommes :

  1. input: ph5.8 200ppm runoff: ph6.8 1800ppm
  2. input: ph5.5 200ppm runoff: ph6.9 1000ppm
  3. input: ph5.1 200ppm runoff: ph7.0 1800ppm

So as you can see its really weird no matter how much i lower the input ph the runoff ph still raises.
Has anyone ever seen that or even heard of it ?
I dont really know what to do.
Thanks, Happy Growing :slightly_smiling_face:

Some pictures:


This is your whole problem: worm castings are full of N which you are dissolving into solution every time you water. Worm castings IME raise the PH to near 7.0.

What you have frankly, is crappy soil. Neither soil nor soilless. It will be almost impossible for you to do anything with.


Ignore your PH run off, it’s also not very accurate.
If you want an accurate ph reading then YouTube how to do a soil slurry test and do it from below surface. Close to the middle as possible.

This is only addition to what is said above of course.


I would add that at 27*C anything under 55% RH is causing the plant to over transpire regardless of growth stage the plant is in. Therefore it is pulling nutrients from the soil at a faster rate than it should. This could be compounding your high soil N levels.

At 21*C 50-60% RH is healthy for a plant in late veg or early flower.

Lowering nutrients for your lights on condition is probably well advised. At 27*C in late veg early you should aim for 65-75%RH

27C in late veg early flower is a great place to be as 25-30C is considered optimal …but you should aim for 65-75%RH to get your vapor pressure differential in check.

Im sorry i dont agree with what you are saying im using coco coir with peat moss with perlite as a organic grow meduim it is great for doin organic grows as long as you mix in ur organic ingredients like bat guano and volcanic rock dust and superworm frass and worm castings and organic compost and quite frankly i would rather use this then ffof or ffsf most of the ff products are to rich in nitrogen and other fertilizers which make the soil to hot ,and if top dress coco coir with superworm frass and bat guano theres no problem also if you make a nutrient tea or a banana and super worm frass tea it works great ive had nothing but good results ,also if this person is having problem with soil ph being to high a teaspoon of coffee in two to three ltrs of water will do the trick and the coffee with give the plant some of the minerals that it needs

None of that was listed so I stand by what I originally said.


His mix is coco perlite and worm casting not peat. Makes a difference. So I’m with my friends on this might have a point about the rh and temp deal up there too. I’d cut the nutes til it start looking back on track again. Good luck.


What you are describing is a more balanced ‘soil’ medium. What was listed above was NOT. Without PH buffers his PH is going to be out of whack. Volcanic rock dust will do just that as will the addition of powdered gypsum and dolomitic lime. Mixing coco, perlite and worm castings guarantees problems.


Each to there own on this u have ur views i have mine ,i had a look at the npk rating for worm castings its only 5.5.3 which really isnt much nitrogen to what most bottled nutrients have in them i really wouldnt think that little bit nitrogen was cause that much problem since its only rating 5% nitrogen i could see it being problem if it was around 8-10% nitrogen but hey im still learning with this whole organic growing

Go back and read the title. It has NOTHING to do with N excess. It DOES have to do with PH. 20% worm castings in coco/perlite will overdrive the media towards PH 7.0. Do you not get this? Seriously.

I personally have experienced this: have you? Thus the reason for my response. Yes; you can build soil diy but you need more than 3 ingredients if you want to grow cannabis.


Like said im still learning about the whole organic growing and yes i have made a mistake with this one im too tired and stoned so i didnt understand it properly ,i have had a battle with high ph in my soil thats all the highest my ph has been in the run off is 5.9

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Imo easiest path to most success with coco is to treat as soilless and feed daily to good amount of runoff.


Once you add that many ingredients, why even start with coco? Just build an organic soil. Coco works best as an inert medium that is fed daily to runoff. It’s for people that want to know exactly what their plant is getting every day, and not guessing if they get a deficiency if they added too many worm castings or too much bat guano. You know what it’s getting so you don’t have to guess. That’s the beauty of coco IMO


Jack’s in hydro… just sayin!…:wink::v::sunglasses:


You know it @HappyHydroGrower :call_me_hand:t3::v::bear:


My 2 cents. Mind you, it is only worth 2 cents.
This and other of your postings tend toward I know better or more than I actually do. It may be the way you say things but that is how I interpret many of your replies. I suggest asking for confirmation if what you are thinking is correct. Or for more information to better understand the issue.
Everyone here is trying to help those that need help, want more information etc. etc.
Rather than confront, ask " why this if this is true" . Why do worm casting increase pH when the N is only?
If I am off base, then follow Gilda Radner’s character Emily Litella recommendation “Never Mind”.


No its not like that at just a miss understanding on my behalf thats all

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I did not know that, i heard this ratio would work good if you want to use some organics but also mineral nutrients.
I like to listen to TheDudegrows podcast they mention this ratio too, could it be anything else i might be doing wrong?
Or what could i do to still get most out of this grow would you keep feeding only water for a bit or should i go back on the nutes?

Thanks a lot

I will look that up, thanks