Controlling aquarium algae can seem like a never-ending quest. Maintaining good water quality is one of the most important on-going facets of maintaining a healthy tank. Excessive amounts of algae can have a detrimental effect on your tank and its inhabitants. Excess algae can have several different causes which need to be identified and eliminated, along with the water being cleaned.
Keep in mind, when it comes to maintaining aquarium water quality, the size of the tank can make a difference. Larger aquariums are often easier to maintain, especially for beginners. Because the water must be properly treated for the fish and plants to survive, having more water allows you a wider margin of error and a more forgiving environment.
Controlling aquarium algae starts with identifying the problem. Cloudy aquarium water with a greenish tint is usually a sign of algae bloom. Two common causes for this are too many nutrients (generally phosphates and/or nitrates), and too much lighting. A high nutrient level is often caused by overfeeding your fish. The excess food falls to the bottom of the tank and decays, releasing phosphates. These phosphates, in turn, lead to excessive algae growth.
An excess of light, not only from the tank light but also from room lighting and too much sunlight, can also cause algae bloom. However, don’t always assume that less light is better. In fact, having to little light can also cause algae growth, especially in tanks without live plants. In tanks with live plants, full spectrum lighting is most effective in controlling aquarium algae.
Because algae consume oxygen at night, algae bloom can quickly deplete the oxygen levels in your tank. Be sure to try to increase oxygen circulation while treating the tank to control aquarium algae, to prevent problems for your fish. Clean the tank by vacuuming the gravel, cleaning the filters, and performing a partial water change. You can also use chemicals known as flocculants, which pull together small bits of debris into larger clumps that can be filtered out. To prevent future problems, reduce the amount of food and 
determine whether changing the amount or type of light is necessary.
Controlling aquarium algae helps maintain a healthy environment for your fish. Regular water changes can help with this. Change 2 to 5% of the water in the aquarium weekly, if needed. Changing less than this will not generally have enough positive impact to be worthwhile; changing more than this can be detrimental to the aquarium. If you do not perform small water changes weekly, a monthly water change should be done. If done monthly, this change should be around 15% of the water in the aquarium. Changing the water helps remove chemicals that are not filtered out, and helps to keep the gravel clean. When algae problems are identified and treated properly, controlling aquarium algae becomes just another part of your tank maintenance.
