The growth of algae is a fact of life that all aquarium owners will face sooner or later. Some algae growth is normal and healthful, but an overgrowth of algae is ugly and can be dangerous for fish and plants.

Algae can appear as a brown, greenish, reddish, or film residue that drags over tank glass, gravel or substrate, accessories, and plants inside the aquarium. There are ways to prevent this overgrowth and, in many cases, reverse it as well.

What Causes an Overgrowth of Algae?

Like all plant life, algae thrive on three basic needs: water, light, and nutrients. If there is an excess of any of these variables, then algae can grow as fire, as well as herbs that grow in a garden.

Your aquarium can’t go without water, but it can control the amount of light and nutrients in the water. Some common reasons for overgrowth of algae are:

• Lights left in a long time
• Aquarius in direct sunlight position
• Fish overfeeding
• Spending a lot of time between water changes
• Maintaining the water environment with a high level of nutrients

Avoid Ingesting Excessive Algae Growth

Knowing what causes an overgrowth of algae is the first half of the battle. Then work to prevent or rectify an overgrowth of algae.

• Reduce lighting: Don’t place the tank where there is direct sunlight, even during part of the day. Sunlight can, and will, promote algae growth. When using artificial light, make sure it isn’t stronger than necessary and is not in more than eight to 10 hours each day.
• Fewer foods: Most owners feed their fish, which increases phosphate levels in the water. Feed small portions and look the fish eat. If you don’t eat all the food in five minutes, you’re eating a lot. Always remove foods that are not eaten promptly.
• Water changes: The only most crucial way to avoid algae is to carry out regular changes in water. Switch from 10 to 15% of your aquarium’s water each week to keep nutrients in low water. This will eliminate nitrate that accumulates in aquariums, one of the main fertilizers for plants!
• Know your water: Try your water source. If you are high in phosphate, you should consider using the phosphate removal chemicals available in your aquarium warehouse, or find another water source, such as filtered water. In addition, it is advisable to test for nitrate, because some water sources have high levels of nitrate. It does not do much good to change the water if you’re adding nutrients back to the aquarium with tap water!
• Clean it up: If you see algae start growing on glass, rocks, or other hard surfaces in the tank, remove them. Scrape the glass, remove the stones, and rub them. Clean the gravel when making water changes.
• Keep plants alive: Plants alive will absorb many of the nutrients that algae thrive on top. Less nutrients in the water mean there is less fuel for the overgrowth of algae.
• Keep algae-eating fish: Keeping the sacseous flying fox, Plecostomus, Otocinclus, or another algae eating fish will help reduce some of the algae in the tank.

Types of Algae

If you notice an accumulation of algae in your aquarium, then you need to get rid of it. To do this effectively, you need to know what kind of algae you have. Knowing that the algae will help determine the cause and the cure. Take a look at common types of algae and how to handle with them.

Brown algae: Also known as gravel or silica algae, these algae are common in new tanks and will coat the tank in leaves, which are easily cleaned. It is usually harmless and will eventually disappear as the tank matures.
Blue algae: Also known as sludge or algae smear, can be caused by an excess of nitrate and phosphate in the water. In most cases, this is not really algae at all, but cyanobacteria. It can spread quickly and can be hard to control. Good water care will help, but if your water supply has phosphate, you may need to use special treatments to remove excess nutrients. Erythromycin is effective against blued green algae, but using it judiciously, is likely to damage the colony of beneficial bacteria in its biofilter, too.
Red or bearded algae: this is the hardest algae that can be eliminated, and usually appears on plants. A drop in a weak bleach solution (5 to 10%) for a few minutes, often kill this type of algae.
Green algae: This is also known as flat hair, yarn or algae. It’s a healthy type of algae that each tank will likely experience to a certain extent. As long as the tank is kept well, it won’t grow excessively. This is the seaweed you eat with algae-eating fish, so try using some of them in your aquarium for control.
Green water: Also known as flowering algae, this is caused by the growth of tiny algae that are suspended in water. It is one of the most frustrating types of algae to remove, as it can not be cleaned or scraped like other algae. Changes in water are generally ineffective because the remaining algae will grow back quickly. The use of a diatomic filter or the complete block of all light for several days is usually necessary to conquer the green water. Try the water to make sure it doesn’t contain ammonia, nitrite, nitrate or phosphate because they will all promote algae growth.