Rodi

[Nanonut]

I just set up an RO/DI unit to use for my saltwater tank. Is the RODO water okay to use with my freshwater? I've just been using tap w/ amquel but would like to use the RODI water if its possible.

[ChicoRaton]

To prevent major ph swings, I'd add something to raise the KH, like baking soda.

[Nanonut]

what ratio do you recommend?

[PumaWard]

Why do you want to switch to RO?
Are you having problems with your tap water in your tank?
It would probably be best not to use pure RO water in your tank, you would want to use a half and half mixture (half RO, half tap) for water changes as well.

If you aren't having any problems, it would be easier to stay with your tap water. Your fish are also used to your tap, so switching over should be a slow process.

EDIT:
What fish do you currently have in your tank?

[Nanonut]

I'm really not having any sort of trouble with the tap water. I just figured that I was using the RO water for my marine tank and knew it was best RO water for marine and din't know if the same was true with freshwater. I'll stick with the tap I think than.