reverse osmosis in a freshwater tank?

[lifeform]

Hi, is it ok to use reverse osmosis water instead of tap water when doing water changes? Would the reverse osmosis water be more beneficial than tap water or is there anything in tap water that the fish need? Thanks

[Lotus]

There are a lot of things that fish need in tapwater. The buffers (carbonate hardness) keep pH stable, and there are other trace elements the fish use. A mix of RO water and tapwater is a happy medium for lowering pH/hardness while still keeping the water stable and healthy.

[Cichlid-Man]

Agreed. Though whats in your tap water? If its something like heavy metals then using mostly or pure RO would help you out. Whats your tapwater like? pH?