Sorry, I don't think my question got answered. What is the difference between r/o and r/o+DI? I'm concerned about gH/kH/pH. I think DI will remove most if not all of gH&kH where just plain r/o will maintain certain levels? Right or wrong?
Using tap water for most fish is fine. But, there are some soft water fish and wild fish that would benefit by addition of r/o water to make it softer, for one thing. I am adding r/o water to my altum angel tank as I don't think keeping them at tap water is an option. I can reduce my pH with co2 injection, but softness is one thing that r/o water is good for. I also have another tank that I have some wild fish in as well, bosemani rainbows, congo tetras, clown loaches, to name a few. I have also been trying to keep some discus as well. It hasn't been going to well and I wonder if I had used some r/o water to soften the water whether that would've helped. This would mostly apply to wilds.
falcon