Yeah, the primary reason that I wanted the RO unit, is to provide pure water for the fishies, but now I read that the unit does remove some things that the fishies would need. Another reason is that pure water = no alage. I do not have alage yet, but I know it will come some day. I guess that tap water should be fine. I saw people saying on this forum that the brown alage are caused by lack of light. If thats true, then why do WalMart easily get brown alage in their tanks, since the lights are all on 24/7/365. I've always thought that the brown alage are due to excess light.
Thunder