I have a rodi system for my reef tank. My daughter has a 10 gallon beta fish tank, would you recommend just RO or RODI and then add the needed minerals back to the water?
@Hillam - DI is much more common in reef tanks and generally unnecessary in freshwater. Both RO and RODI will bring the TDS well below what your Betta will want. Ultimately, RO is all you need for a Betta but if you already have RODI, just use that and remineralize so the minerals your Betta needs will be there.
