I'm converting an old fresh water 10 gallon aquarium into a reef tank, and i'm wondering on the necessity of having a filter on it. I have a hob aquatech 5-15 gal filter. but i'm thinking of potentially removing it all together and using a powerhead like the hydror koralia nano 240 instead as that would allow me to control where the flow goes and build the scape i want (i can't do that with the hob filter cause my aquarium's lid only allows for it to be attached to the back of the aquarium). would that be ok (not having a filter). from my understanding right now the biological filtration would come from the substrate and the live rock as well as the soft coral in my aquarium (xenia and mushrooms). would that provide enough filtration for keeping inverts like sexy shrimp and boxer crabs? Also any recommendation for a low flow power head woulf be appreciated.