1. You should keep the temperature in your aquarium constant. Constant change in the aquarium can be dangerous for the fish in your aquarium. Keep a quality heater and accurate thermometer to ensure that the water stays stable for the aquarium.
2. 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.
3. You should never used any alcohol to clean the inside of your aquarium. Alcohol can pose health problems for the fish in your aquarium.