1. Avoid placing your aquarium near a radiator or any other form of heater. The heat given off by these devices can easily upset the temperature balance in your aquarium. Raised temperature levels can kill off the fish and plants that you have in your aquarium.
2. When starting out a new aquarium, it is best to add hardier species at first. Once your aquarium ages a bit and gets settled, you can start to add more sensitive fish to the aquarium.
3. It is a good idea to perform a frequent water change and cleaning schedule. Changing the water in your aquarium will keep it clean for the fish that live in the aquarium. Keep a full stock of the water treatment chemicals you will need for this purpose.