How To Get Rid of Algae in Your Hydroponic System: Tips & Tricks

green and brown plant during daytime

Cultivating healthy and abundant plants can be taxing for even the most experienced hydroponic enthusiasts. Tirelessly monitoring pH levels, nutrient concentrations, humidity, temperature, and other factors to keep your plants thriving under artificial light, you may experience some hiccups along the way. We’ve put together this quick guide on removing algae in your hydroponic system to help you get back on track. 

Algae is a microorganism that thrives in moist conditions like those in a hydroponic system. While they are considered a hostile element because they tend to reduce the amount of light penetrating through the water and clog up pipes, they can also indicate that something is wrong with your setup.

What Is Causing Your Algae Problem

The first thing you should do when trying to get rid of algae in your hydroponic system is to figure out what is causing it. While its presence is never a good sign, knowing what’s behind it will help you take the best action to eliminate it. Before you jump into treating a problem you might not even have, it’s always a good idea to assess your hydroponic system first and see if there is a problem causing the algae to grow in the first place. 

For example, if the pH levels in your water are out of balance, the wrong pH might encourage the growth of different types of algae. Knowing what is causing the algae to grow can help you fix the problem and clean up your system simultaneously. 

If you notice that your plants look unwell, are growing slowly, and their leaves are turning yellowish, there might be too much nitrate in your water. This excess nitrate encourages algae growth. Since algae thrive in warm, humid conditions, you may also want to check your system’s water temperature and humidity levels. If things are too cozy in there, it’s time to check your system for leaks, unplugged equipment, and other issues that may be contributing to excess humidity.

Identifying the type of algae in your system

If your hydroponic system is home to a particularly stubborn algae species that are difficult to eliminate, you can always consult a handy algae identification chart. It will help you identify the type of algae you are dealing with, making it easier to find an effective way to get rid of it. 

There are many different species of algae, and each one comes with its own set of characteristics. Some of the most common types you might come across include: 

- Cyanobacteria: This type of algae is called blue-green algae. It forms thick, greenish mats and can quickly become visible in hydroponic systems with insufficient nutrients and light. 

- Green algae: Also known as “slime” algae, green algae are typically found on the walls of hydroponic systems. They are usually green in color and produce a thick, slimy goo that can be difficult to remove. 

- Rust algae: This type of algae is very similar to green algae. It forms on the sides of hydroponic systems and is usually rust-colored. 

- Black algae: These algae are widespread in hydroponic systems. It is usually black and can be found on the walls of your system.

If your system is infected with blue-green algae, you can try adding more CO2 to the system to promote the growth of other beneficial microorganisms that will help to keep it under control. Alternatively, you can add a small amount of hydrogen peroxide to your system to kill it off.

The quick and easy way to get rid of algae

If you are dealing with a particularly stubborn type of algae, a quick and easy way to get rid of algae in your hydroponic system is to scrub it away with a scrub brush. You can do this at the end of each growing cycle and then use a hose or a pump to clean the walls of your system thoroughly. Scrubbing your system with Hydrogen Peroxide has also been shown to reduce algae from returning as well.

Since identifying the type of algae growing in your system is essential but can take a bit of time, we recommend you take a quick and easy route to get rid of algae until you’ve identified the type. You can create a potent algae-killing cocktail using a hydrogen peroxide solution and purified water. Different algae have different levels of sensitivity to hydrogen peroxide, and this method is effective against all types of algae growing in your system. After taking drastic measures, it’s best to identify the type of algae growing in your water and devise a more long-term plan of action to keep it away.

A popular method of removing algae in a hydroponic system is to create an algae bloom. The algae will feed off of the nutrients in the water and die off, reducing the number of algae in your system. While this method is relatively effective, it will take some time to show results.

How to get rid of algae with UV light

If you are dealing with a stubborn type of algae that is difficult to eliminate, you can always turn to UV light for help. UV light harms the DNA of algae, which will cause it to die off. While you can use UV light to get rid of algae, it is essential to remember that they also can kill your plants. Therefore, placing a UV light on a timer is a good idea to only turn it on for a few hours each day. It will help you avoid killing your plants while eliminating algae. UV lights are relatively inexpensive and have the added benefit of improving the overall health of your plants. They can be used indoors and outdoors and quickly hooked up to a timer.


Algae is a common problem in hydroponic systems. While it is important to keep an eye out for it and take steps to eliminate it as soon as possible, it is also important to remember that it is a natural part of a healthy ecosystem. If your hydroponic system is nutrient-rich and full of CO2, you almost certainly have algae living in it. While it may be an unsightly element, it is generally harmless. Like any other unwanted microorganisms, the best way to get rid of algae is to maintain a clean and healthy ecosystem.