I have a biocube 29, I had it cycled and I have about 45 lbs of live rock in it. It has been running since like November 2011. But sadly I have had some fish die off. There also seems to be alot of stuff gathering on the bottom and when I try to siphon it out I don't succeed as to I have the really small live sand. I am considering just taking all my rocks out scrubbing them off and putting all new water in. I still have 3 hermit crabs and 2 turbo snails alive. I didn't know if there is any upgrades or something I should use instead. I have an oceanic biocube protein skimmer, but it doesn't seem to work worth a hoot! Any help! I'm getting frustrated and almost want to give up!! Thanks for any help!