My Buckeye unit just came in yesterday. I have not hooked it up yet because I'm not sure where it's going. For me, initially, it wasn't worth it on my 29 since the amount of water required was minimal. Now that I am moving to a 210, it's necessary. However, even with my 29, if I didn't have RO ready to top off, I would end up using tap water, which would in turn raise my phosphates and result in algae. When I had RO on hand, I never had that issue.