I have a BFS RO/DI system that I got from Aquarium Design when I lived in San Marcos. It needs a new membrane and all new media. I found it to be a little inadequate for my 55gal tank, but I think it's because I'd hook it up, use it to make enough water to do a change, and unhook it. I've heard that not having it plumbed to allow water to continuously circulate is bad for the membrane. I plan to fix this in the future with a bigger system that is plumbed to a water line. Sound good?