Here's what I think is an excellent article on community fish and plants for those of us affllicted with very hard water. http://www.aquarticles.com/articles/management/ranson_african%20cichlids%20and%20plants.html It's a combination of rainbowfish and relatively peaceful African cichlid species, plus plants that will do OK in the hard water and the Africans don't like to eat. I guess livebearers would work in this tank as well. Maybe bigger ones. Synodontis catfish would be a good bottom feeder. Do you guys have any critique of the suggestions here or additions based on your experience? Thanks!