My tap water is Reverse Osmosis. I am having problems stabilizing tank. What can I do?

I am having major problems stabilizing my tank. My tap water is Reverse Osmosis and I just seem to get a bad "slime" over everything including my fish. I have lost all my fish including my algae eater. I need help. I have a 29 gallon tank. I had Neon's, a Betta and my algae eater and they are all dead.