Originally Posted by Sillyfishies
Without water flow the rock wouldn't be filtering much. You can have a very successful tank with no real mechanical filtration. I would just use rock, powerheads, and a skimmer.
No...? The powerhead stops detritus from settling... Rocks can filter without out them.
Nor did I state that you can't have a successful without mechanical filtration.
A skimmer is also part of your mechanical filtration. It removes dissolved organics in the water, but it is a machine. Making it mechanical filtration.