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?
@MidwestGuy. 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. 
Or if you can get some flora kleen would cut down on amount of water you would have to run through. 
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)