RO/DI Ok for Betta ?

[Myka]

You could always add a couple snails to eat the algae.

[Captainhemo]

Think we';ll just run with the RODI water for now and see how it goes.
Guy at teh LFS says that is what keep their FW fish in so that is what he has been in all along

[Myka]

It will take a while to kill him anyway.

At the very least, you could do him a favor and use Aragonite sand if you're going to stick with the RO/DI so there is at least some amount of pH buffering capacity.

Fyi, in most cases you can use the waste line of the RO/DI unit for most freshwater fish.