I ran a gallon of RO water through my tank. Outside of leaving a light film of white powder inside the tank, there were no other negative effects. I prefer distilled water, as I dislike too frequent cleaning. Where does your fish tank water come from? If it is safe enough to drink, it is OK in your...

I’m pre-CPAP (first trip to the DME on Tuesday), but wondered about using RO/DI instead of distilled. If mineral deposits are the main concern, then the water I use in my reef aquarium (before adding salt that is) should work just fine. Cool, one less thing to worry about (where am I going to keep a...