I think it's Brita right? Their website claims to take out almost as much as R/O, but I doubt it's that good. I'm installing a 2 stage under sink filter system that is even closer to r/o. It does get out as much chlorine though as r/o
i use one, just the carbon kind. i know that its not as good as ro/di water, it is at least something. straight tap water is just foul stuff for a tank, a good way to get an cyno/algea breakout. i still add chlroine out to the water though.