The wet/dry is probably the most effective filter available for a FO
tank with no LR
. If you have LR
in the tank, you really don't need any other biofiltration. The LR
will take care of it. The advantages to a sump: adds water volume to the tank; provides a place to put heaters, skimmers, and other equipment which keeps the tank from being so cluttered; adds flow to the tank...always a plus; good place to dose additives, run carbon, ect...
The disadvantages of a sump: increased evaporation...not a lot, but some; increased chance of flooding the floor if you use an external type overflow.
If you're willing to buy a "reef ready" tank with internal overflows, you reduce the chances of a large spill to nearly zero. Make sure your sump is large enough to contain all the water that will flow down from the tank if the return pump quits for some reason. I think you'll have a more stable system and easier maintenance if you go with a sump, but it'll cost you a bit more to set up initially. JMHO