Originally Posted by land locked
... The way I have if figured it: Little Giant 700gph, and Koralia 1 400 gph
, That is just at 15.2 gph
circulation. AA folks suggested 10-20 gph
times the tank size was best in a reef tank.
The only thing wrong is that I'm assuming the 700gph out of the Little Giant is the rating of the pump, correct? That rating assumes no head. Head is the height that the pump has to lift the water from the sump back into the tank. The more the head height is, the less the pump puts out in gallons per hour. So 700 gph
is what you'd get if the output was coming straight out of the pump. You're probably running much less. If the pump came with a head/flow chart, you can figure out what that flow is.
For a 75g tank, I'd be guessing you could use two Koralia 2, or even probably two Koralia 3 in each corner of the tank. That wouldn't be too much flow. The Koralia flow rating are a little deceptive because the flow coming out of it is so much more dispersed and wider than say a MaxiJet. That 400gph flow coming out of the Koralia 1, in my opinion, is equivalent to maybe the flow coming out of a Maxijet 400 or 600... which is around 100gph.
But it's nothing to worry about. Adding flow later on is an easy thing. Once you start adding corals, my bet is you'll adjust your flow (quantity and direction) several times, so you'll have plenty of opportunity for change in the future!