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. You need to have some healthy natural bacteria to process the wastes and chemicals in your aquarium. This will take around 4 weeks to grow naturally, but you can purchase products to speed up the process.
3. When keeping aggressive species of fish, it is best not to introduce peaceful species of fish among them. Aggressive fish will tend to bully the more peaceful fish. Make sure to thoroughly read about the compatibility of the selected fish for the aquarium.