Hello last week I flushed twice using 3 gallons slowly and I have also tried changing the light intensity and ph a little bit from 6.0-6.3 possibly I went the wrong way but I know her ec was still fin the 800’s so that’s when I did a second flush.!!!
I'd say growing in a mix of Coco/Promix may be playing a factor here, considering they have two different optimal PH points. Coco is a pseudo-hydroponic medium, promix is just soil.
I'd up the PH and see if that does anything, as you can't really change the medium at this point.