i use sponge filters in my minnow/crayfish breeder tanks...for a 55 gallon tank, i use 2 4" filters in each 55 gal tank + a couple air stones..
i've tried 4" and 6" clay pots, they liked the bigger one, but i got more eggs under a big flat rock propped up for them to swim under
with the sponge filters you just squeeze them out a few times in a bucket of water once a month or so
get some plants (anachris is good) and your good to go
api fresh water test kit is good to have too
