Probably me. I never really change up anything from gnats, because if the soil dries out decently they die off. Never been a prolonged problem. Sorry bout that.
Again sounds like me. Promix is diff cuz as u said, u keep it wet. Mediums are important to know ya know. Im in soil, and let my plants go 4 days without touching or looking at them.
All that said, im elated u got them this close to harvest. Excellent researching and grow so far!