Algae, that green-brown growth on your aquarium and aquarium decorations, is an unsightly annoyance. While it may be impossible to completely do away with algae in you aquarium, as it thrives in a healthy environment, there are some things you can do to control its growth.
Algae are a chlorophyll producing organisms, which means that, like plants, they need light to survive. Make sure the light in your aquarium is not too strong. Avoid putting the fish tank near direct sunlight. If you are suffering from a sudden influx of algae, lower the light level in your aquarium for a while.
The warmer your aquarium is, the more algae it will have. To control algae, keep the temperature on the low side of the recommended temperature for the fish you keep. Keep in mind that the temperature may drop at night, and do not sacrifice your fish's health for algae control.
Snails and algae eating fish are a must-have for any aquarium. Use caution with snails, as some varieties are prolific breeders. Also, be prepared to supplement any algae-eating organism's diet if algae levels get under control.
Time to Scrub
From time to time, use an aquarium scrub brush to clean the inside glass of your aquarium. If your decor is getting covered, remove it and give it a good scrub, but do not use any chemicals on it if you intend to put it back in the tank.
If these measures do not work, you can purchase a chemical algaecide. Monitor water quality carefully if you add anything to the tank, including an algaecide.