I have decided to try an experiment. I normally use RO/DI water that I make. It is such a hassle to make it though. When I first got into saltwater tanks over 9 years ago, I used tap water with conditioner. I had no problems at all but eventually went to RO/DI water. I have decided to go back to the tap water with the conditioner. I have been doing this over a month now will no ill effects that I can see. All my water testing is fine and TDS is fine. Does anyone else do this? I have had to scrape algae off the glass even less when using the tap water with conditioner vs the RO/DI water.