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. Purchasing fish that feed off of algae is a good plan to take care of an algae problem in your aquarium. You could also try cutting back the amount of lighting in the aquarium or get an algae treatment chemical to take care of any algae problems.
3. Having a quarantine tank on hand is a very good practice to use if you frequently buy new fish. The quarantine tank will weed out any sick fish that could possible get into your aquarium and cause harm to the other inhabitants.