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Any aquarist knows the sight of algae. It’s that sort of greenish carpet that covers substrate, rocks, glass and other decorations. If it builds up too much in the tank, it can present a problem for the entire ecosystem. Plus, it can block the scenery of a planted tank.
But, it’s important to note that algae blooms are a more of a benefit for an aquarium than a problem. Many aquatic creatures love algae and it does act as its own form of filtration for the ecosystem as a whole. Sometimes, it can even look cool in your aquascape, giving it a more of an organic appearance.
Causes for Algae Growth
So, why does algae grow in fish tanks? Because the conditions are perfect for algae, especially when there are plants and other organic matter in the tank. In other words, when nutrients, oxygen, CO2 and light go out of balance, algae will begin to grow.
Various combinations can make this happen since algae can withstand a variety of inclement conditions. Poor distribution of CO2, too few nutrients and too much light are some examples that contribute to an ideal environment for algae. But there are other reasons why algae can grow.
More about Imbalances
The amount of available light affects the speed at which plants absorb CO2 and nutrients. More illumination means plants get more of what they need. Unfortunately, many aquarists provide too much light with a lack of attention to nutrients and concentrations of CO2.
This means the plants will suffer. The deficiencies in growth results in “melting” and, thus, algae blooms show up. Using a drop checker when lights are on and off will help to measure and gauge CO2 levels. Also, investing in a well-balanced and complete plant food will ensure they get the required nutrients.
When organic waste builds up in a tank, it results in ammonia saturation within the environment. This is a sure way for algae to thrive. It’s also why having a regular care and maintenance schedule is important. Cleaning out all filter media and vacuuming the substrate will mitigate organic waste.
Decaying leaves from plants contributes to organic waste too. Trimming and pruning the leaves and stems helps to remove the source of ammonia and promotes growth. Always use a clean and sterilized tool to do this. Also, weekly partial water changes will dilute waste product concentrations, which is what algae thrives on.
If there isn’t a strong current flowing through an aquarium, CO2 and nutrients won’t circulate well enough to reach all the plants. Filters and powerheads should range 10 times more than the volume of an aquarium for proper circulation to occur.
The filter should have the right flow rate in conjunction with the size of a tank. It may be necessary to add extra pumps to ensure proper water flow. When plants have adequate CO2 and nutrients, algae has little chance of taking hold.
In order to prevent an oily, scummy film from building on the surface and to bring oxygen into an aquarium, surface agitation must occur. But, too much agitation encourages injected CO2 to escape. Using an air pump when the lights are off for about six hours will allow for proper oxygen to diffuse in the tank.
This is because plants only use oxygen when the lights are off. When illumination is available, the plants breathe CO2 and it decreases the levels of oxygen. This makes other life in the tank, including fish and plants, fight for available oxygen. Also, it causes beneficial bacteria to die, which increases ammonia and the proliferation of algae.
Higher temperatures also deplete oxygen in an aquarium. This means more oxygen and CO2 may require an increase during the summer.
A Note about New Tanks
Newly planted tanks always have a buildup of algae in the beginning. Brown algae is almost always the first to show itself, forming brown patches on leaves, rocks, glass and other surfaces. Because ammonia is excessive at this initial stage, brown algae is unavoidable.
Until the tank matures, frequent removal is imperative. A toothbrush can easily clean this off from all elements affected by it in the tank, including glass, plants and décor. But, to rid the tank of it entirely, water changes will be necessary.
Performing water changes regularly helps reduce organic waste in the tank. About three to four changes within the first week are essential. Then reduce the schedule, bringing it down to once a week after two months.
Lack of Beneficial Bacteria
Any time a new aquarium goes into operation, there’s a lack of the nitrification cycle. This means there are not enough good bacteria that can convert ammonia efficiently. The excess ammonia causes algae to bloom, which will suffocate plants, block light and deprive the environment of CO2 around the leaves.
When large amounts of algae are present, the plants will die. To fight rapid algae growth, weekly water changes must take place until the tank is mature enough. Aquariums heavy with plants will allow for a faster maturation process.
Reducing Algae with Animals
One of the best ways to control algae growth is to have plenty of aquatic creatures that love to eat it. Depending on the type of water in the tank, Amano Shrimp, Siamese Algae Eaters, Catfish and Assassin Snails are all good choices. But, you should do some research and investigation in the various species available as cleanup crews.
This is because some creatures can become invasive, like snails, and present a whole other issue altogether. But, animals like shrimp, can consume uneaten fish food along with algae, thereby helping to maintain the tank’s ecosystem and reducing waste.
Controlling Algae Growth
Algae are part-and-parcel to having a planted tank. It’s unavoidable and can become a problem, but also necessary to a healthy ecosystem. It’s important to maintain this delicate balance to ensure all living things can thrive and survive.