Runoff pH technique

So this is most likely my OCD kicking in, but help me with details of how you check/adjust pH… (Goal 6.5)

For example: (does this sound right).

Week1 water with distilled (pH not adjusted, as it is usually in that 6 - 7 range).

Week2 collect enough distilled runoff
(Hypo) pH is now @6.1
Now I water adjusted to 6.9 to bring up to the goal of 6.5.

Week3 collect runoff with the straight non-adjusted distilled or the 6.9 from previous week? (This is the confusing part to me, does it matter?).
Runoff should now be in the 6.5 range

Rinse and repeat.

Yes this is probably my OCD being too detailed but otherwise it wouldn’t be called OCD now would it? I think i have CDO… it is when your OCD is sooo bad you even have to spell it in order :grin:

Do you check/adjust any different?

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I grow in soil. The pH range for soil is 6.3 to 6.8 with 6.5 being the sweet spot. When I test my runoff if it is anywhere within that range I am happy and do not worry about it

If you are in hydro then the range is 5.5 to 6.1

If I am just watering I adjust my water to 6.5 before going in .

If it is a feed then I mix my nutes and test the pH which in my case is always in the above range for soil. Then I test the runoff and if it is in that range all is well.

Hope this makes sense.


I am probably “picking nits” here but I was more concerned with checking the runoff in subsequent weeks after an adjustment…

Specifically Do you use the previous weeks’ pHed water to collect new runoff or do you use straight 6.5pH? Am i making sense?

I know the desired numbers goals and to adjust water after adding nutes (im not there yet).

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Okay, every time you water or feed nutrients, you take a runoff reading, let’s say it’s 6.0 immediately following a watering. The next time you water you want to compensate for 6.0 up to 6.5, yes. Let’s say this time that your reading is 6.3. The third time you water now, you will use 6.3 and try to get it to 6.5, yes.

Is that clear? Hope it helps.

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I think i got it… Sounds to me like use the previous (leftover water) to get your new runoff… Then up or down the pH of (any clean water) then that water is ready to use for next watering.

Works for me, that’s the way I’ve been doing it.

Im just exiting the seedling stage and was under a humidity dome and little water was needed and my girls were complaining (typical woman huh? j/k).


I love Brock! I just noticed that. Lol

Wait, are you using your runoff water to water your plant? No, that is not what you want to do. Always start with fresh water.

Yeah Brock can bust some heads…
NO NEVER watered with the runoff water… Who do you think I am “the monarch”? :joy:

I think we are on the same page except my book had the cover ripped off, let’s see…

  1. New seedling watered at 6.5 pH…

  2. When thirsty water with 6.5 pH/collect the runoff…

(the runoff is hypo 6.1)

  1. Prepare new clean water @6.9 pH

  2. When thirsty again use the newly 6.9 pH’d water. And collect runoff which should now be in the range of 6.5.

  3. A couple of days later when thirsty again water with the 6.9 pH created in step 3 again collecting the runoff.

  4. If this runoff is (hypo) 7.1 pH then create and water with 6.4 pH

Continue until harvest?



Excellent! You got it! Have a great grow, Brock.