Diatomacious
Well-Known Member
This is what I think the culprit is. The carbonate in the lime. Carbonates seem to have an unlimited supply of alkalinity and will continue to get sweeter the longer they stay wet. Why you should never use carbonates in a "true" hydroponic setup or you will be chasing the pH constantly. Anyone with a pH meter could verify my observations. I immediately (the same day) fertilized the media after flushing, and the flush was at least the volume of the soil in runoff. True that the solution is very acidic it's just that the media contains way more than enough lime to deal with what is in the solution. No lime was added by me, just what came in the bag.
Anyway that's why I don't bother to pH my nutrient solution.