How to Manage Algae in Aquaponics

Algae growth is a common problem for aquaponics systems that can confuse new aquaponics growers. Algae growth is normal when raising fish, but it can get out of hand if preventive measures are not taken. If left unmanaged, algae can cause problems to your aquaponics system because they can impact the pH and nutrition of your system

Preventing and managing algae problems in your aquaponics system is not a difficult thing to do. Simple measures which we will discuss in this article can help prevent and manage the growth of algae in your aquaponics system.

Algae Problem in Aquaponics Systems

Algae can grow anywhere in your aquaponics system, including in or on the grow bed and in your tanks. When unprevented and unmanaged algae can cause problems in your aquaponics set up, and here are some of them:

  • If left, unmanaged algae will cover the sides of your tanks, the roots of your plants and prevent them from getting thenutrients they need.
  • Algae also consume the nutrients that your plants need.
  • Algae can clog your hoses, pipes, and pumps, which can stop the flow of water and nutrients.
  • Algae need oxygen to flourish, and because it lives in the water, it may remove the dissolved oxygen from the water, reducing the oxygen for your plants.
  • Algae can also reduce the amount of oxygen for your fish, which will affect their health and your entire aquaponics system negatively.
  • Algae can cause pH swings that can negatively affect your system's health. 
Algae in Aquaponics System

How Algae Grow in Aquaponics Systems

Algae are a form of plant life that comprises several types of plant-like organisms. There are different types of algae, and they can appear slimy, bubbly, stringy, and in an array of colors. Algae can multiply quickly if the places they are growing have light, air, and nutrients. An aquaponics system has all that algae needs to grow, making it an ideal home for them.  

Preventing Algae Growth in Aquaponics Systems

Prevention is better than cure. The same goes for aquaponics. The best practice is to prevent algae growth in your aquaponics system. Here are a few things you can do to prevent algae growth in our system.

1. One way to prevent algae growth in your aquaponics system is to deny it any light. But, this can be difficult because fish and plants need light to survive. What you can do is to exclude light from your system as much as possible to keep the algae from growing. You can do this by avoiding the use of light-colored or clear grow beds and clear tubings. If you already have a transparent grow bed, paint the outside with black color or line your grow bed with black plastic to keep out the light.

2. Another way to prevent algae growth in your aquaponics system is to deny algae the nutrients it needs to grow on top of the grow bed, where it can cling to the grow media. You can do this by adjusting the flow of your water pump so that the water will not cover the top of the grow media. Don't let the water rise higher than about 1 inch below your grow media's top. This level is high enough to allow plant roots to reach the water but low enough for the grow media's surface to stay dry so algae can't grow on it.

Aquaponics Systems

Methods of Removing Algae in Aquaponics Systems

If you fail to prevent algae growth and have algae trouble, then you must deal with it. Below are the methods of managing algae growth in your aquaponics system.

1. Covering the Fish Tank

Covering your fish tank will not affect the fish in your system, but it will deprive the algae of the sunlight needed for their growth. Covering will prevent any spores from multiplying and stopping algae growth before it becomes a problem.

2. Algae Eaters

You can also use algae eaters to manage algae growth in your aquaponics system. The most common algae eaters for aquaponics are shrimps and other fish species. However, this type of fish species only eats algae when they are small. Once they grow bigger, they prefer to eat plants, so you need to watch their growth. 

3. Humic Acid

Humic acid can be added to the system to reduce algae growth. It is very effective in darkening the water, thus depriving the algae of sunlight which prevents it from growing. Humic acid is an excellent addition to your system because it is great for your fish and plants, and it can help chelate several essential plant nutrients.

4. Mechanical Filtration

Mechanical filtration plays a significant role in removing algae. A mechanical filter can be installed in the system, and it will remove the algae and spores. The mechanical filter includes filters, screens, settlement tanks, and other mechanical means of removing algae from the solution.

5. Physical Removal

Another method of removing algae in aquaponics systems is by removing it physically. 


Getting the right balance for your aquaponics systems can be challenging, especially if some unwanted enemy, like algae, can start growing and establishing itself. However, preventing and understanding the best way of managing algae can help succeed your aquaponics system. Being vigilant and taking notes on the changes you noticed, and acting on the problem as soon as you see them, can really help. Read our aquaponics maintenance tips for more ideas on how to maintain your aquaponics system.



Leave a comment (all fields required)

Comments will be approved before showing up.