A filter like a Brita is not going to remove much of the stuff we need removed from water, they are basically a carbon filter which removes chlorine, taste, etc. Using distilled water may be a good alternative for you. You don't want spring water or artesian well water or anything like that because of high mineral content, it may be good for us but it is bad for our tanks. The only thing a dechlorinator is good for is if you were using tap water, the only exception would be to neutralize bleach used if you were trying to sterilize something and then you would use it to neutralize the bleach (at a higher than normal dose).