Lax;

It's possible the water at the lfs is even worse than what you're using, unless it's tap water. Depends on the store. If I remember, Austin tap water is pretty bad. I'd do a series of big water changes, like 3 or 4 40% changes, with water you KNOW is good quality. If you get it from Jim, it'll be good quality. You're going to need to either find a good source for water or buy a filter. Either way I'd get a TDS meter to check what you;re putting in your tank. Nanos are pretty sensitive, you know.