1. Clownfish do not always need to be with a sea anemone. Clownfish use anemoneís in the wild and they are not completely necessary in the home aquarium. If you insist on owning an anemone, you need to have plenty of experience to take care of it as they can be difficult to manage.
2. When adding particularly aggressive fish to your aquarium, it is a good idea to move around the rocks and such in the aquarium before placing the new fish into the aquarium. Moving the rocks in the aquarium will allow the fish to go back and stake out their own territory.
3. Make sure to always keep your aquarium level when placing it. If your aquarium is uneven, the weight of the water can press against the seems and this can cause major problems in your aquarium.