I have a 55 gallon reef tank in the making. Right now I have a Rena XP3 (yeah, I know) which moves 350GPH, a Koralia that moves 750GPH, and another Koralia that moves 1,400GPH. That is 2,500GPH on a 55 gallon, or 45X turnover
I have noticed that when all are running, it is tough to keep the sand from flying everywhere, it drives me nuts
The configuration is:
Koralia 1,400GPH:::: ::::::::Koralia 750GPH
Hopefully my hieroglyphics make sense? I am thinking that maybe I should swap the Koralia's so that the Rena and the 750GPH Koralia are on the same side, to counteract the 1,400GPH Koralia. The two Koralia's are angled up to stir and agitate the water surface for gas exchange, and both are angled toward the back glass.