Yes that is what I did out on Siesta Key - tap water with prime - no problems. But when we got Discuss - RO water only. Recently we have moved in to a home out by the celery fields in Sarasota and the ammonia in the tap water here is over 4ppm. I came home at lunch today to find 3 of my 22 new tropical fish dead in my 65gal tank. I have always used RO water from my RO system to do water changes but we have since sold our Discuss fish and decided to go with just some Tetra's because it's easier to maintain. Well after seeing 3 of my fish dead at lunch today, i started testing the tap water and sure enough the ammonia is over 4ppm - crazy high. I'll do a water change of 40 gal tonight and again tomorrow until the ammonia drops.
Anyone else experience this?