The mechanical filter attachment is a screw on attachment with pads that fits on AquaClear models. I've used it in freshwater and although you have to change the pads often, it keeps the water crystal clear.
For my 29 gallon, I would need 290 to 435 gph
(per the calculations above).
The Remora skimmer will give me 85 gph
I have 2 powerheads, one is rated for 350/400 gph
and the other is rated for 250/270 gph
. The Magnum is rated at 350 gph
I see many people using 2 powerheads, a canister filter and skimmer (in small tanks like mine), but this would give me way to much flow and I don't want to stress out the fish or critters. BTW, I haven't set this up yet, but I have all the equipment already, so just trying to see what would work best.