How to Kill Algae In Hydroponics

Algae is the term used to refer to the weeds found in any hydroponics system. They are also found in lakes and rivers as a primary food source for some wild fishes. While it has some notable benefits, it could still pose a huge problem in any hydroponics system.

Algae in Hydroponics is killed by removing it. Use Algaecide. Drain and clean the system. Scrub and flush in every corner and the tubing. Clean every component. Keep checking and repeating the process when needed.  

If left untreated, the algae will continue to build up and cling to any surfaces in your hydroponics system. It will reach the tubes to the pumps that can eventually destroy the system. Hence, your hydroponics system is unsafe when algae – an anathema – is present.

Algae produce a terrible smell when it starts to decompose. Not only will it pollute the air around your hydroponics system, but it can also serve as a barrier to your growing bed.

The algae will clog the holes that connect the plants to the water that provides the nutrients. When this happens, nutrients are depleted and there’s a dramatic drop of dissolved oxygen in the system causing the plants to suffocate and resulting in a weaker plant that hardly fights other pathogens.

Interestingly, the algae in the hydroponics system take many forms. It can be furry, slimy, stringy, or bubbly that comes in different colors ranging from green, blue-green, black, red, and brown. Since algae thrive in the same conditions as plants, that means a hydroponics system is an ideal place for algae to also grow.

How to Remove Algae from Your Hydroponics System

Unfortunately, there is no one-size-fits-all when removing algae from your system because it depends on your hydroponics setup and the severity of algae infestation.

Now that you understand how and what causes algae to emerge in your system, the next step is to control them. The following steps will help you manage the algae in your hydroponics system.

1. Know Your System

You must know your system, such as how to remove the grow beds, where the tubes are located, and other essential aspects of the system. This will help you remove algae effectively without damaging any parts of your system.

2. Establish Access To Remove The Algae

The next step is having access to remove the algae, and this is the reason why you have to know your system.

You can’t simply take the algae out from the system without being careful that you might step on important parts.

Remember, algae do not grow on dry surfaces; hence you know where to locate them and have better access to remove them.

3. Use Algaecide

A commercial way to cure algae infestation is using an algaecide. They can control the blooming of algae but this method comes with its caveat.

If you overuse or misuse the algaecide, it will ruin the root system of the plants and you don’t want that to happen.

4. Assess The Amount Of Algae In The System

This step is very important and you have to check all corners of your system to know how far algae have gone inside your hydroponics.

You are lucky if it does not reach the pump or air stones and you can easily remove them.

But if it reaches the deepest areas of your system, you need to perform a thorough cleaning.

5. Drain The System

In severe situations, you have to drain the system to give it a good clean. There might be algae spores lurking around the system that is not seen by the naked eye.

Again, hydroponics systems are different, some use pumps to drain and others use drain valves only.

It doesn’t matter how you drain your system. What is important is to remove the old nutrient from the system to ensure that no algae spores are left behind.

6. Clean The System

This is similar to system cleanup after harvesting, but you do it to get rid of algae.

You have to make sure that the smallest traces of algae, pathogens, and other bacteria will be removed. You can use food-grade hydrogen peroxide unscented bleach.

7. Get Your Hands Dirty

Part of cleaning the system is to give it a thorough cleaning by scrubbing the insides. Before this, you have to dismantle the system into several parts and give each of them a good cleanup.

Add the hydrogen peroxide or unscented bleach and scrub the channels and conduits, then run the system for a few hours to transmit the algae into the tank and drain them easily.

Do not forget to scrub the sides of the tank as well. If you are using bleach, make sure to flush the system three times to completely remove any residues. After the final draining, wipe down the tank and channels with a clean towel.

8. Do Not Forget The Components

You also have to clean the air pumps by using food-grade hydrogen peroxide or unscented bleach but make sure to triple wash it. Soak the components and give them a good and gentle scrub to remove algae spores hanging around. Do this process until they are spotlessly clean.

Understanding Algae Growth in Hydroponics

Generally, algae is a plant-like aquatic organism granting them the ability to grow in any aquatic environment.

They need the same core factors that plants require to grow such as sunlight, water, and nutrients. This is the major reason why algae emerges in hydroponics systems.

Aggressively invasive, algae will relentlessly dominate any hydroponics system if left unchecked. It will steal all the nutrients, even the small amounts, from your plants and will continue to do this because you don’t want to starve your plants.

The algae will thank you for that. The only solution left is to eliminate it completely to let your plants grow in peace.

Furthermore, algae are scarily stubborn. It means that algae don’t feel threatened with your sterile and well-contained hydroponics system.

It will find a way to enter your system one means or another. Hence, a perfect system in which plants can grow is also a perfect condition for algae to thrive and thus kill the plants – predators and victims!

You have to keep an open mind because algae will still have a chance of entering your system no matter how you set it up. Once you acknowledge the threat of algae, you will keep on thinking of better ways to protect your system. When it comes to algae,-  control being way more effective than prevention.

How to Prevent Algae from Entering Your System

Although prevention is less effective than controlling the algae, it is still helpful to take preventive measures to minimize the chances of algae infestation in your system.

Preventing an algae infestation requires knowing what causes algae to emerge in your system. Thus, it is recommended to follow these steps:

1. Use Opaque Or Colored Materials

The main reason why algae emerge in your system is light exposure. By using opaque and colored materials, it will minimize the risk of light from penetrating inside the system, and hence it will severely discourage algae to grow or photosynthesize.

2. Cover The Exposed Water

This usually happens when the holes in the growing bed are bigger than the plant itself, allowing light to penetrate.

If your system is small, you can use any solid-colored material to cover the place where the lights enter.

For larger systems, you have to use a tarp or plastic covers to conceal the system from sunlight exposure.

3. Use a UVC Light

If you want to go extra in eliminating algae growth, you can install a UVC light in your filtration system. They are effective in preventing the emergence of microorganisms including algae in the system.

Remember, running a UVC light can add to your expenses and you have to consider your financial capacity before installing it.

4. Adding Grapefruit Seed Extract To The System

Grapefruit seed extracts contain anti-parasitical, anti-bacterial, and anti-fungal compounds that effectively combat algae growth with the right dosage.

It is recommended to use 5 to 10 drops per gallon of water in your system. If you are suffering algae growth for a long time, consider using this effective method.

5. Use Barley Straw Rafts

Several studies have shown that aerobic decomposition of barley rafts releases a chemical solution that eliminates algae growth but it takes a longer process which makes this method ideal for large scales hydroponics.

However, you have to make sure that your system has enough dissolved oxygen for the aerobic decomposition to take place.

But be careful with the algae death because it decreases the dissolved oxygen in your system affecting the aerobic decomposition of barley straw rafts.

Final Thoughts

Because algae are ubiquitous and prevalent, it follows that controlling algae seems to give you a better chance than preventing it. Just follow the necessary steps to control and remove the algae in your system to keep your plants healthy.

However, you can still prevent the algae by not allowing the sun to enter your system. It might require you to spend money outside your calculated expenses which can be hurtful to some.

Yet maybe it is better to invest in eliminating algae than losing your plants – whether you have them for profit or pleasure, they’re your plants and worth fighting for!

Jenny Marie
Tribal Writer

Edited By
Patricia Godwin

Patricia Godwin

Patricia has many years of experience as a content writer on various subjects, but her first love is gardening. She’s never met a plant she didn’t like and, consequently, she writes about every type of plant you can think of. Once an avid gardener with a herb garden, a succulent rockery, and a rose garden – to mention a few. Nowadays, she’s constantly on the move searching for interesting plants to bring to your attention; and explain to you all the details you need to grow, care and maintain these plants.

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