Hi Cheryl. I live on the moors in England and my last house tap water was straight off of the peat moors. It was like week tea, very soft and slightly acid. My discus loved it and bred quite happily.
Have you tested your tap water to see if it's a natural brown from the environment or just mucky. If it's soft and acid then your mollies and polarities might be unhappy.
When I set up a new tank I test the local water first and then plan the environment and fish around the water. It's much easier than fighting it all the time.
Test your tap water (I never trust the local water authority water reports) and then go from there.
Hope that helps a bit. Steve.
