How much flow through sump?

[drhyed]

After a year with my 75 gallon planted fresh water tank, it was torn down for a move and this time its going to be a FOWLR salt water tank. Im still deciding on a bare bottom tank (wife likes the look) or a shallow sand bed, any pro/cons of either? And for the big question, many people and places suggest 10-15 times tank volume turn over per hour. I few say only 4-6 times turn over gives the skimmer more exposure time and less water flow also equals less noise. But Ive also heard this can be bad because the skimmer removes both good and bad from the water. I will be using 1 power head on each end of the tank (probably a mp10 on one end and a 40 on the other) for circulation. This might be overkill for now but Im only going FOWLR until the price of good led's comes down or my wife surprises me with a redsea S600:lol:

Thanks
Jay

[thegrun]

The general rule of thumb is 5-8 times your DT size through your sump. The rest of the flow comes via powerheads. I would shoot for 20 times your DT for total flow, anything less tends to have low flow zones which will trap detritus. There are some slight buffering advantages to using sand, but it is largely a personal choice for looks (I like sand) unless you plan on keeping a sand dwelling fish in which case it is necessary.

[A sea K]

At the time I was researching proper set-up for my tank the reccomended flow was 3 to 5 times system volume through the sump. Take into account any headloss when you select a pump, height of return, plumbing length, # of elbows, etc.
As far as in tank circulation. Your MP 40 (3000gph) and MP 10 (1575gph) will be more than sufficient for a 75 gal FOWL. With a return pump yielding 5X turnover(375gph) and the two vortechs you will have over 65 times total flow in your display and that is alot for a FOWLR, you sure wont have to worry about detritus settling though.