Aquarium Algae

How Do I Get Rid of Aquarium Algae?


Algae growth is a problem that most aquarium hobbyists struggle with at one time or another. While some algae growth is natural, even beneficial for your tank, too much algae can have negative effects on your aquarium and on your fish. Excessive algae growth can be unsightly, coating your tank walls and decorations with thick, green slime. At the same time, algae can be an important food source for herbivorous species of fish. If you have a problem with algae growth or simply want to prevent it from becoming a problem, there are a few simple things you can do.

How Algae Grows

Like all living things, algae require certain nutrients in order to thrive. The main things algae need to grow include light, nutrients and carbon dioxide. Algae are photosynthetic organisms which means they utilize light as an energy source to convert carbon dioxide into complex organic compounds. Algae functions in much the same way as plants, using many of the same nutrients and turning carbon dioxide into oxygen. The most important nutrients algae need to grow include nitrogen and phosphorus. Decaying plant matter, accumulations of uneaten fish food and dead fish are the primary sources of these nutrients in a freshwater tank and the higher the available quantity, the more algae growth you are likely to see.

Remedying Excessive Algae Growth


There are many different kinds of aquarium algae as well as a variety of removal methods. Some types of aquarium algae can be easily removed by hand – simply wipe or scrape the algae off the walls of your tank using an algae scrubber. For more stubborn algae growths, you may need to use a razor blade or remove tank decorations and use a bleach solution to kill off the algae. If your tank is going through an algae bloom, you may need to take a different course of action. Algae blooms are common in new and un-cycled tanks – they involve the rapid growth of algae as a result of excess nutrients. An algae bloom may colour the water in your tank green or brown and it may settle as a film on tank walls and decorations. If your tank has an excess of nitrogen or phosphorus as a result of built-up organic wastes, you may experience an algae bloom.

Treatments for algae growth may vary depending on the type of algae and the cause for its growth. If your tank receives too much sunlight, the remedy may be as simple as moving the tank away from windows and skylights. It may also help to limit the amount of artificial light your tank receives to between 10 and 12 hours per day. If a sudden increase in algae growth is related to an excess of nutrients in the water, performing a 25% water change may help. In new tanks experiencing algae blooms, the algae may go away on its own once the tank has cycled. In order to speed up the process, however, you can try adding some live nitrifying bacteria to the tank. If you visit your local pet store you may be able to find a chemical remedy for algae growth, but most aquarium hobbyists advise against this remedy. Algae killers could harm the plants in your tank as well as killing the algae, and there could be negative side effects for your fish.

Preventing Aquarium Algae

If you maintain your tank properly and keep up with your routine maintenance tasks, you should not have trouble with excessive algae growth. Performing weekly water changes and keeping an eye on the water chemistry in your tank are two of the simplest ways to limit the amount of nutrients available to algae. Avoid over feeding your fish because the uneaten fish food will sink to the bottom of the tank and, as it breaks down, produce ammonia and nitrogen. If these nutrients become available in excess, you may see a sudden spike in algae growth. Keeping your tank out of direct sunlight and maintaining a stable water temperature can also help to prevent algae growth because algae are more likely to grow in warm, well-lit waters. Another easy way to prevent algae growth from getting out of control in your aquarium is to introduce an algae-eating species of fish. Chinese algae eaters, otocinclus catfish and plecostomus are a few of the most popular freshwater algae eaters and they are relatively easy to raise. If you employ several or all of these precautionary measures, you shouldn’t have to worry about excessive algae growth becoming a problem in your tank.