I would not try an 8g with tap water. That is your problem. You keep adding phosphates, silicates, heavy metals and other garbage. It's just too nasty of water for an 8g feasibly.
that's assuming you are using tap.
Well, it should be easy to fill 8gal of ro/di right. I still carry jugs...ever walk by your tank and decide to sacrifice your bottled water?
HERS 120 gal, 2 X 400w + 4 X actinic HIS 45 gal, 250w + actinic RIP mixed reef , started 5/04