I have a 30 gallon tank... One small angelfish, 5 rummynoses, 4 pearl danios, and 3 BN plecos... all about 3-4 inches. I have a Fluval c-4 HOB, which pumps 264 GPH, a Fluval c-3 which pumps 153 GPH, and an AquaClear 30, which pumps 150 GPH, for a total of 567 GPH... I do weekly to bi-weekly 30ish percent water changes, sometimes a little more. I do regret not buying the AC50, but I would have to cut a space in my hood, and the current is already pushing it for the angel... Is my filtration adequate? I could buy a new filter to replace one at my birthday soon... but I think I would like a more reliable, newer heater instead...