Nice grow bifta.

How many plants did u grow?What was ur yield?Clones or seedlings?

I think ur idea is pretty good caddy for maximizing ur stones t'd and eveything, but if one of ur pumps actually did go out i would guess the forced air flow from one tube to the other would seep water back and flood ur room.
Id stay with one stone per bucket from each pump.
No on the white buckets, u want dark, but if u already have um then tape some black garbage bags around them until u cannot see light penetrating into the bucket at all.lol i seen ur post in a dif thread.