I am going to be seting up a fish only 29 gal tank. I am trying to keep cost down (i know that is hard when getting into this type of hobby), so i was hoping to get one or two clown fish. I was going to go with crushed coral but am thinking about using live sand. Is one better than the other, does one do better at providing home for bio-bacteria. Also, what is the minimum amount of live rock i could start aout with for one clown fish. And how much if i added a second clown fish. I will have powerheads pushing water throuhg the live rock. Anything else i am missing?