How do You Adjust Runoff pH?

Growing in soil. FFHF to be precise. I checked my runoff for today’s watering and my runoff pH was 5.8.

I’m currently flushing with several gallons of 8.5 to 9.0 pH distilled. I’ve put 3 gallons through 2 of them so far and runoff is ~6.1. Seems like a slow way to adjust, but I don’t want to introduce something too acidic.

Is it the right way to go about it?

@FlxerPower. Try not to go too high on your input water for ph.
Should go in at 6.8-6.9 ph.
3 times the volume of water to pot size.
5 gal pot = 15 gal water.
Last watering ( couple gal ) should be a very light nute mix. :v:
Or if you can get some flora kleen would cut down on amount of water you would have to run through. :wink:


Thanks. Yeah, on the light nute mix - I’ve noticed my ppm are going down quite a bit as I flush.


You can’t actually get a pH reading with distilled water because it doesn’t conduct electricity very well. At the point of distillation it has a pH of 7, but it very quickly becomes acidic - around 5.8 pH. Hence your runoff pH.
You could try chasing it with some pH-up, then back down when it gets too high - eventually you will add enough outside material to get an accurate reading. But, that is rather a wasteful exercise.
Instead, you might try a 1:1 or 2:1 distilled to tap water mixture, which should then give you an accurate pH reading you can work with. (Or just use plain tap water, unless there’s something wrong with it)