how to measure water turnover

[kolosy]

when calculating powerhead needs for an aquarium, there's a magic number of 40-50x of the aquarium volume per hour.

however, is that a measure of powerheads going at once, or total powerheads in the aquarium?

i've got 2 koralia k4s in a 46g bowfront. they move 1200gph, but are pointed at each other and on a wavemaker, so both are never on at the same time. should i double that? so that i have 2400gph at any point in time?

this is a 9 m/o mixed reef.

 

[seapug]

Technically, it's the sum of the flow of all the circulation devices that would be on at any given time, but don't get too hung up on the actual number. One pump with 50X turnover blasting a jet of water in one spot in a tank wouldn't necessarily classify as good circulation. It's really about the dynamics of the flow and the corals you keep. Two Koralia 4's on an alternating cycle in a 46 gal. tank should be plenty.