An algae bloom is a rapid accumulation of algae in the aquarium. In this article, you'll learn what causes an algae bloom and the remedies available to solve it.
It is not an uncommon occurrence for novice aquarium hobbyists to turn on the lights in their tank one day to find that the tank water has turned green overnight. In many cases, green water can be contributed to an algae bloom. Though algae blooms may go away on their own, they sometimes indicate a larger problem in the tank that needs to be addressed in order to protect the health of your fish. If your tank is experiencing an algae bloom, or if you simply want to prepare yourself for the possibility, there are a few basic things you need to know about identifying and remedying this condition. Before you can hope to treat an algae bloom, of course, you need to know what it is.
What is an Algae Bloom?
An algae bloom is simply a rapid accumulation of algae in tank water. Algae blooms can affect both freshwater and marine tanks and, in most cases, the algae consist of cyanobacteria - though a single or small number of phytoplankton species may also be involved. The presence of phytoplankton often results in a green discoloration of tank water, though the color may also be red or yellowish brown depending on the species of algae. The most common cause of algae blooms is an excess of nutrients in the tank – particularly phosphorus, though excess carbon and nitrogen can also cause algae blooms. Because algae rely on phosphorus as a source of nutrition, higher phosphorus levels in a tank can lead to increased algae growth.
What Causes Algae Blooms
It has already been mentioned that an excess of nutrients is the main cause of algae blooms in freshwater tanks, but there are a variety of ways in which this excess might be brought about. Overfeeding can result in a build-up of organic wastes in the substrate of the tank which may become a breeding ground for algae. Since live aquarium plants help to absorb excess nutrients, unplanted tanks may be more likely to experience algae blooms than tanks decorated with plenty of live plants. Algae blooms are also very common in new aquariums. In fact, the occurrence of an algae bloom is sometimes referred to as a symptom of “new tank syndrome” by experienced aquarium hobbyists. Before a colony of beneficial bacteria can be established in your tank to maintain the nitrogen cycle, the levels of ammonia and nitrate may be very high. In cases like this, the algae bloom will typically go away on its own once the parameters in the tank have stabilized.
How to Remedy an Algae Bloom
If the algae bloom in your tank is caused by an excess of nutrients or toxins, performing a large water change could help solve the problem. Even if you change 50% of the water in your tank, however, it could still take a few days for the green tint to dissipate. It is also wise to perform a water test in order to determine whether the chemistry of your tank water is abnormal. If it is, take the necessary steps to bring the abnormal level back to normal. In some cases, direct sunlight can cause excessive algae growth and remedying the condition can be as simple as moving the tank to a location where it receives less direct sunlight. If you are utilizing a high–intensity light bulb in your tank, consider lowering the wattage or reduce the number of hours you keep the lights on each day. Lights should be on no more than 10 - 12 hours a day. While there are chemical remedies for algae blooms available, these products are generally not recommended – particularly in tanks with live plants because they could harm the plants as well as killing off the algae. Some aquarium hobbyists recommend UV sterilization as a means of killing and preventing algae. UV sterilizers target microscopic organisms like algae and can provide a permanent solution for algae control in the home aquarium.
Tips for Preventing Algae Growth
The key to keeping algae growth at a minimum in your tank is to limit the amount of nutrients available for algae growth. Avoid overfeeding your fish so as to limit the build-up of organic wastes in the substrate of your tank. Adding live plants to your aquarium is a great way to limit algae growth because live plants will naturally compete with algae for nutrients. Keeping the aquarium water clean through regular water changes and adequate filtration are also important for limiting algae growth. If the water quality in your tank declines, you are more likely to experience an increase in algae growth. One of the easiest ways to keep algae growth under control is to introduce one or more algae eaters into your tank. There are a variety of algae eaters available including invertebrates like freshwater snails as well as fish such as Otocinclus Catfish, Siamese Algae Eaters and Plecostomus. Different species of algae eaters feed on different types of algae, so if you know your tank is prone to one particular type of algae growth, select an algae eater that tends to feed on that kind of algae.