RO/DI & Freshwater

[terrymr]

Now I have my RO/DI system for my reef tanks - I was wondering what I'd need to add to RO/DI water to use it in my freshwater tank.

 

[Hop]

For topping off, nothing. For filling up a whole tank or running a large water change, I used to use RO right and adjust my pH for my discus tank. But that was a long, long time ago

And PS... RO is sufficient. No reason to run the DI for the FW tank.