Algae eaters - make sure that you always have a varied population of algae eaters in your aquarium. The different kinds of shrimps, snails and algae-eating fish prefer different kinds of algae, and the more different kinds you have, the less the risk of a specific kind of algae taking over your aquarium.
Water change - one of the most efficient mediums against algae. The water change ensures that a surplus of nutrients does not accumulate in the aquarium.
Light control - Tropica recommends that you do not have more than 10 hours light over your aquarium per day. Use a turn on/off clock, so that you need not remember each day to turn the aquarium on and off - and remember to check regularly that it actually works.
Moderate feeding - cause no. 1 for algae problems is overfeeding or a too big population of fish. Tropica recommends that you have no more than 1 cm fish per L water in the aquarium and preferably less.
Avoid a too high temperature - temperatures above approx. 26°C almost always give cause for algae problems. Especially thread algae likes the heat, so if you have problems with algae, try to lower the temperature to 22°C or less.