1. If you use your tap water, you should make sure to remove the chlorine from the water before you add it to the aquarium. Chlorine can be very harmful to some of the fish in your aquarium. You can purchase kits to remove the chlorine from your aquarium at many retailers online.
2. In larger aquariums, you should put a few scavenger fish in the tank. Scavenger fish will help to clean up left behind food and wastes from the other fish in the aquarium. This is a good eco friendly way to keep your aquarium clean.
3. You should never add uncured live rock to the aquarium. Doing so can release harmful levels of ammonia into your aquarium.