well I outsed the heater, looking for a different filteration method. Its been about two maybe three weeks and I have been doing regular 1-2 gal water changes. Everything in there seems to be happy, although i did find my coral banded shrimp with one of my hermit in his mouth........ but do you really think a skimmer and sump tank on such a small tank? I understand the need to double the water amount for filteration and what not, But I thought that the point of a nano tank was to be on a desktop?? I admit i don't like the bubble sponge method at all, can't see how it would work. haven't had much luck with bubble skimmers either! Now this tank is going to be corals only no fish at all.(soon) I already stated another 8 gal reef with a fish, so far. So would there be a hang filter or canister that would do an adiquit job??