pH question I should know by now

[OlderNOTwiser]

But I don't! I just put a gallon each into my Gorilla grows. Plant "A" was water/nutes at 6.6 pH and runoff was 5.5 pH. Plant "B" was fed at 6.5 pH and runoff was 5.8 pH. With this information I need to know (or at least understand) what the pH is at the root zone. Is it halfway between the in and out pH? Some magical FM number from the sky? Should I be feeding in the alkaline range to get the runoff range more to the 6.2 - 6.5 range? I know this is important and don't want too many more grows guessing. What's the point of checking and pHing the water/nutes if I don't know what exactly it means or what way I should compensate?

[Canuck147]

That is too much to worry about - therefore - I have never ph'ed my runoff water - don't intend to start.

So I'm no help - maybe it's important or .............

[Booger789]

I have learned some strains are real ph sensitive. Others not so much. I used to ph my runoff and I have quit doing it except when I flush a plant as I am more curious then I think it’s really needed. I had a northern lights clone that no matter what ph I set the water to it would turn yellow a little after a feeding. And kept doing it all the way from veg to flower. So I did not clone that plants genetics. It was a good smoke but not what I wanted to grow again. Some plants I think are more sensitive than others and that’s just the nature of the beast. Just keep after it and keep growing.

[Farmall]

Rather than put an entire dissertation on root zone pH.... this article is long but covers a significant window of the value of pH. It’s really a good article that will either persuade you to be pH focused or pH indifferent

https://www.growweedeasy.com/ph#why-pH-cannabis

[OlderNOTwiser]

Yea, as soon as I got to the part that said it to me I was like....This is what happens when you post stuff straight!

[Rwise]

I build my own organic soil, put everything thats needed in it, and dont worry about the PH. From there the girls tell me what they want, then add that as needed. A headbanger wanted sulfur, lots of sulfur or she turned yellow.

[Toker1]

Run off = half way between input and root zone.
In the cases above, your root zone would be near 4.5 - 4.8

[OlderNOTwiser]

I was first checking on my outdoor grow this past summer. Runoff was about 5.5 pretty consistently. I was watering/feeding at near 7. So roots were near 4? I started bumping up the pH on that one but aphids cut the grow short. Now I have two Expert Gorillas going (indoors) and they're the A and B plants above. One is poorly quad-lined and the other just LST bonzai. If I'm not overthinking too much I'd need the input up to well over 7 to begin bringing the runoff up. How high of an input pH is safe? Don't want to start too basic...like giving them a lye bath. Doubt that would end well.

[Toker1]

Check with the soil manufacturer. Flush at the highest recommended ph until root zone is with in spec.