We used tap water that was treated and sat before being put in the tank. The way they transported the fish was by putting them in a large pitcher with their own tank water. Because all of the tank water was new I left the old (disgusting!) filter in for the first few days so all the good old bacteria could grow, and when I finally added the last fish (I did it over a short period of time) I added all the old tank water the fish came in. I'm not sure what all the fish are but there is one HUGE placastamous(sp?), 3 neons, 1 silver dollar, some fancy tailed guppy, and 3 others. It was a well established tank before it was moved. My In-laws (where the tank was) live about 30 min north of us, but definately at a higher elevation.