return pump question!~?>?

[jdav]

im 1 step closer to setting up a bare bottom tank!@

its gonna be a custom 92 gallon acrylic cube (30x30x24)

just curious how many gph should be returning to the tank from the sump? i got the thing with the skimmer pump being stronger than the return pump, but how many times and hour do i need to turn over the tank volume in the sump?

[gwaco]

kind of a tough question . you can;t really use the old book formula . you need whatever amount its gonna take to get stuff out of your system . if you use alot of internal flow that gets stuff up and moving around in the water column and its making it to the overflow to the skimmer than you may not need the gigantic flow . i can only tell you what works for me . i have a 180 gal and use a gen x 4 (mak-4) rated at 1190 gph , so with head loss maybe 800- 900 gph . but i have tons of internal flow that does a good job of getting junk out and to the skimmer ( a big honkin one ) that run with a 2160 g.p.h. pump . so as you can see by most examples , i would be considered running low at approx. 5times turn over rate . i know that this isn't probally the answer you were looking for , cause everyone wants some type of written number to work with .

[Fly Guy]

I wouldnt even worry about how many times you are turning your sump over. Just try to run your return near or less than the amount of water your skimmer can process in an effort to send as little unskimmed water back to the tank as possible, and all will be well.

[King-Kong]

While the above advice is all great for removing nutrients, it may not be great for microbubbles.

Sump construction and flow are greatly connected, and having too small of a sump and too much flow will result in turbulence and microbubbles getting into your display tank. A cube tank probably means that you dont have much room underneath for a long sump with a settling area, or a sump large enough to handle large amounts of flow; be careful not to go too strong with the return pump.