Pump for a closed loop?
 

I'm going to use melev's example of a closed loop, but I want more returns. The tank is a 33L (48x13x13). If I used a mag 5, on paper, it would turn the tank over 15 times an hour. Do the spread out returns slow that down, though? Would a mag 7 do it or would I just be better off with two seperate pumps, one at each end?

Also, is the Mag my best choice here? The tank's going to be in my living room, so I'd like it to be as quiet as possible.


I hope that all makes sense, because I have no idea what I'm talking about. Any help would be much appreciated!

I would use an OceanRunner 2500 or Eheim pump before the Mag. Both are much more efficient meaning less watts per gallon pumped and create less heat gain in the tank, not to mention being much quieter. OR pumps are on sale at Drs Foster & Smith for less than half waht Eheims go for and are actually more efficient. I have 4 of them and swear by 'em.
Something you need to answere is are you going to include something like a SCWD for current switching? If so plan on about a 25 to 30% flow loss. If you use something like an Oceans Motions Squirt two way it does not cause a flow loss like that and gets you better current switching albiet for more money. I recently made the switch from SCWD to Squirt and love it.