Algae in Fish Tank

Algae in Fish Tank
Algae growth in fish tanks is normal, but in excess, these aquatic organisms can be detrimental to the fish and plants. This article provides some information about the various aspects of this condition.
Like other plants, algae need sunlight, water, and nutrition for a healthy growth. Small amounts of algae in a fish tank is considered beneficial, as the fish feed on them. In large amounts, algae can be detrimental to the life of the fish as well as the aquatic plants in the tank. Excess algae growth in a fish tank is like overgrowth of weeds in a garden. Both algae and weeds ruin the appearance of the otherwise beautiful fish tank or garden respectively. While weeds can stall the growth of garden plants; algae is not good for the health of fish in the tank.

Types of Algae in Fish Tanks

When it comes to algae in fish tanks, the most common ones are brown algae, green algae, red algae, and blue green algae. Knowing the type of algae in your aquarium may prove beneficial for choosing the right way to check its growth.

Brown algae: Otherwise known as gravel or silica algae, the brown algae are commonly seen in newly set up fish tanks. Usually, these algae disappear, once the fish tank matures. It is said that brown algae growth in a new fish tank is due to the high levels of silicates, nitrates, and phosphates. Brown algae are mainly linked to the presence of high levels of silicates that leech from the new glass of the tank or the new sand or gravel. Once the amount of silicates is reduced with water changes, the growth of brown algae slows down and they disappear eventually.

Green algae: With a decline in the level of silicates, brown algae disappear; but, it may be replaced with green ones. Green algae are normally found in almost all fish tanks, in small amounts. They can be in the form of spots or hairy filaments. These algae are consumed by algae-eating fish; and can also be removed manually. Green algae may not be a problem, in aquariums with routine maintenance, but care must be taken to prevent their overgrowth.

Red Algae: Otherwise known as brush or beard algae, red algae are the toughest types to be removed manually. They are typically seen in fish tanks with high carbonate hardness and high pH level. You can curb the growth of red algae, by tackling these problems. Otherwise, get some Siamese algae eaters, which feed on red algae.

Blue Green Algae: Though known as algae, blue green algae are cyanobacteria, which are capable of photosynthesis. These bacteria flourish in fish tanks with low nitrates, and high levels of other nutrients, like phosphates. Seen as a slimy coat of different colors, cyanobacteria are harmful for the fish and plants in the fish tank, as they release harmful toxins. These bacteria are not eaten by fish, but can be removed manually, as they are found in the form of sheets. Care must be taken to prevent their regrowth, by improving the aeration of the tank. This problem can also be prevented by using erythromycin.

Causes of Algae Growth

Small amounts of algae can be commonly seen in fish tanks. Only when it becomes out of control, that algae growth poses a serious threat to the ecosystem of a fish tank. So, it is necessary to understand the causes of algae growth, and the measures to control the same. One of the key components for algae growth is water, which is abundant in a fish tank. Others are nutrients, sunlight, and absence of predators.

Light: Direct sunlight can offer a favorable condition for algae growth in fish tanks. Other sources of light can also contribute to algae growth, if the fish tank is exposed to such light for very long hours. Too little light is also not advisable, as it is can promote the growth of brown algae.

Nutrients: Like other plants, algae too need nutrients for growth. They need nitrates and phosphates, which are abundant in a fish tank. Excessive nutrient level could be due to the high levels of nitrates and phosphates in your tap water, which is used in the fish tank. If your tap water does not show high levels of nitrates and phosphates, then the possibility is that you are overfeeding your fish, or the fish tank is overcrowded. The reason why this happens is, left over food and fish waste can also lead to high levels of nitrates and phosphates in the water.

Algae-eating Fish and Aquatic Plants: Absence of algae-eating fish and aquatic plants in a fish tank is also a favorable condition for algae growth. While algae-eating fish feed on algae, aquatic plants use up the nutrients in the water and starve the algae.

How to Get Rid of Algae in Fish Tanks

There is no need to remove algae from the fish tank, in case of a small growth. If they are growing at an alarming rate, adopt relevant control measures. The following are some of the methods to get rid of the algae growth in your fish tank.
  • Never place your fish tank in direct sunlight. Exposure to other sources of light should also be reduced to eight to ten hours a day; and a maximum of twelve hours, if you have live plants in the tank. Too little light can also cause trouble, as it could contribute to the growth of brown algae.
  • Another cause for algae in aquarium is the high level of nutrients, like nitrates and phosphates. In such cases, care must be taken to avoid overfeeding, and to remove the left over food and fish wastes regularly.
  • In case of badly affected fish tanks, you can use a gentle scrubbing pad (for acrylic tanks), or a razor blade (for glass tanks) for cleaning.
  • Aquatic plants are good for curbing the overgrowth of algae; as they consume the nutrients in the water, leaving very meager amounts, which will not be sufficient for the algae to survive.
  • Aquarium care must include regular water change, at a rate of 10% per week.
  • Get some algae-eating fish. There are many types of such fish, which feed on algae and prevent their overgrowth.
  • Clean fish tank accessories, like filter, on a regular basis.
Most cases of algae overgrowth can be tackled or prevented with the above said methods. Don't provide favorable conditions for algae growth, by adjusting the key components, like nutrients and light.

Minor algae growth is normal and inevitable; and often enhances the natural looks of the fish tank to some extent. However, take care that the algae in the tank do not overgrow, and cause harm to the fish and plants.
poisonous algae in the Red Sea
Colorful aquarium background