1. 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.
2. Cichlids tend to be very intelligent fish. You should do your best to interact with them as some species will respond positively to you arriving home. These fish are very active and if you interact with them, they can develop much better.
3. Goldfish can live incredibly long periods of up to 25 years. You should plan accordingly when you purchase a goldfish.