Preventing and Removing Algae in Cannabis Hydroponics

Algae are an integral part of our ecosystem and life. However, they do not go hand in hand with cannabis! If you see algae in your hydroponic system, it is sometimes dramatic. We explore what this phenomenon is and how to prevent it.


When we talk about algae, you might immediately think of the sea. However, you may be surprised to learn that you sometimes encounter them in hydroponic systems as well. How is this possible? Let’s find out. Algae are a kind of “simple” plants that live in water. In doing so, they have no stems, leaves or roots. To flourish, they only require water, nutrients, heat and light. Unfortunately, your hydroponic setup is a great location for algae, especially your reservoir.


By now you may be wondering what the problem is. Algae seems harmless, but something is definitely happening under the surface. Know that this is a plant growing in the same nutrient solution as your cannabis plants. As a result, algae is competing for oxygen and nutrients with your cannabis. They may not absorb much, but they do prevent your cannabis plants from being able to achieve peak performance. The problem worsens when the algae dies. At this stage, microscopic fungi appear and degrade the plants. This attracts your cannabis’s deadliest enemy: the sciarid fly. This little glutton makes countless holes in the roots of your plants. This creates vulnerable spots where pathogens deal the final, deadly blow.


Now you know how much damage algae can cause. It’s time to get rid of them. First of all, you need to know how to recognize algae. After that, don’t just focus on fighting them, but also do your best to prevent future ones.


Algae generally has a green, fluffy appearance. However, it is also not strange to see red, black or brown variations. The simplest approach is to look for these physical signs, although algae sometimes hide themselves as well. To find them without visual indicators, you often only need to use your nose. Do you notice a moldy, earthy smell? Then you’re probably dealing with algae. Also pay close attention to your plants Do you see yellowing leaves and roots that clump together? If so, there is little you can do, but if you stop this at an earlier stage, it can be prevented.


If algae is already in your system, cleaning with hydrogen peroxide is most common. Make this solution with one part hydrogen peroxide and ten parts water. Then put small amounts in your reservoir regularly. In this way you not only destroy algae, but also give the roots an oxygen boost! However, it is advisable to do this only with older plants. Younger specimens are sometimes damaged, even by a small amount of peroxide. After cleaning, replace all transparent parts of your grow with opaque materials. If this does not work, find a way to make the existing components opaque.


From here on out, it’s all about prevention. Fortunately, you have a number of options. Since it’s not possible to cut out nutrients, heat and moisture, turn your attention to light. This starts with setting up your system. Prevent light from reaching wet areas, the reservoir and other parts where you store water. That way, if all goes well, you’ll never have to contend with algae. Don’t worry if you already have transparent equipment. In fact, it is also possible to wrap it in aluminum foil. If you install UVC lamps in your air filtration system, you also prevent any microorganisms before they reach your system. Algae are also not fans of moving water. So make sure you also have a pump to avoid stagnant water.


We hope this article helps in setting up your hydroponic setup and solving problems. Keep in mind that algae may not be a big danger at first, but they do damage faster than you think. So take the proper steps to prevent them. If they do appear, act quickly. Also read the rest of our blog to learn more about the ins and outs of growing cannabis.