indeed.chesterthehero;2689931; said:all the water in the tank is the same... however all the "crap" collects on the bottom.. its a wise choice to take the crap out of the tank...
if you look around the forum, or just ask around, you will notice an average of 25-30% WC weekly. this includes filter vaccuming, and for some, filter cleaning. obviously, the cleaner the tank, the happier your fish. however, as mentioned, you will need a good amount of bio-filtration if you do a lot of WC. you dont want to remove the beneficial bacteria.