One thing I forgot to ever mention is me dosing kalkwasser in my ATO reservoir. Right now I'm at 1tsp per gallon. I've noticed with the Apex is the Ph is staying around 8.02 or so. I'll continue with this batch and maybe up of to 1.25tsp per gallon. My reservoir is a 5 gallon water jug with the neck cut off. I rest a bag over it with a pebble to keep contaminants out.