I have had three in the past. I kept marine fish at one and fresh at all. Also, full supply of pet supplies and grooming. Best money maker still though was fish tank maintenance, which I started 10 years before buying a store. After I sold the stores, I got out of the hobby for several years, then...........my wife saw a reef tank. The rest of the story you can probably guess. It's fun though because I feel like I'm learning all over again. Things have changed in the last 15 years.