Runoff water at 3.7 pH - Help please

Ok guys,
So I’m posting this topic to get some help on correctly changing the pH of my soil. Currently, my runoff is at 3.7 pH. I’m watering with ph 6 water. I flushed them with ph 8 water, and runoff came out at ph 4. I didn’t want to keep flushing with the ph 8 water, so I’m coming here to ask you guys for help! I don’t know how this happened, but all my soil plants are affected. Any help would be appreciated.

I’m using peat and perlite, 50/50. Started last month with watering with 5.8-6 pH water. Everything was great. I noticed discoloration in plants, so I flushed and checked runoff and pH and TDS etc. Discovered this was the problem, and need help. I use distilled water from the store, and correct the pH and use it. Weekly I was giving nutes as well. Thanks guys!

@pigsquishy got any helpful thoughts?

So I did some research and found a lot of people had problems with low run off in peat, but can’t find any definite answer on what causes it besides it could be old peat.

Have you done a soil test to determine the root zone pH?

Dolomite lime add some to your soil it will raise and help stabilize ph

Verify meters first … what was your tds ?

I’m doing a soil test now, started soaking earlier today so tomorrow I’ll have an answer.
And yea, I remember reading somewhere that peat moss is acidic and breaks down after time.
I doubled checked my meters. I calibrate my pH pen every time I use it (if it needs it, I leave it in 7.0 pH solution when I’m not using it). PPM was at 800 at start of flush, got it down to 100.
I’ll continue to flush with correctly pHed water and see if this fixes the problem.

Now, my other question here; Can I take those plants, shake off as much old soil as possible, and transplant into new soilless media? (I’m buying the pro mix tomorrow and hydro store) Would this work?

You can transplant preferably done well prior to flower expect your plant to take some time to recover

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Ok so I did a soil test yesterday, and checked it’s pH today, after 24 hours.
The soil came out to be 6.2 pH
But that conflicts with the 3.7 pH water runoff.
I’m wondering if maybe the soil in the actual pot is just breaking down and became more acidic, or if maybe I had watered with low pH water before I had got my pH pen delivered.

What would you recommend I do?
My thought is to get off as much soil as possible from the plant, then re plant her into fresh media (the 6.2 pH soil I just tested).

Sometimes it feels like you just can’t win, lol.

This is why it is important to have those pH and EC/TDS/PPM testers and the knowledge of the various techniques to monitor what is happening in your soil or reservoir or even the root zone. Like measuring the run-off throughout the growing process, especially during flowering, as flowering itself, because of the way the ion uptake/exchange occurs at the root zone when the plant is happily taking up tons of nutrients during bloom and trying to create dense nuggets, will create an acidifying situation.

Hope this info helps,


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I used to use peat and Perlite (75%, 25%) and my Ph of runoff was always real low. I fooled around with the Peat Moss and found it to be very acidic. I have since changed to Coco-coir and perlite and the Ph problem went away. I have since changed to Fox Farm Ocean Soil and it is worth the small added price. Remember, I could always be wrong. Good luck. Keep it green.


Is the Fox Farms Ocean Soil a soilless media? Or is it a soil product? I was thinking of getting the pro mix hp, but if you recommend FF ocean soil, I can get that easily as well.

And now I need to ask, why do you think FF Ocean Soil is the best? Is it easy to maintain pH?