Green Algae is Attacking my AeroGarden: How to solve this issue

Green Algae

Green Algae is attacking my AeroGArden have you ever noticed it starting to attack your AeroGarden? At the opening of my AeroGarden where I pour water and nutrients into the bowl, I noticed it starting to turn green. Why is this happening? How can green algae start forming without direct sunlight on the water? I needed to find some answers because I don’t know if this green growth is dangerous to the plants or us, so I started researching this topic.

What is Green Algae?

For algae to grow, it requires sunlight, nutrients and water. It occurs when light interacts naturally with water and grows. But my AeroGarden does not get direct sunlight? It uses LED lights to replicate sunlight!

Green Algae is common, but there are other kinds of algae that grows and blooms. For them to multiply they need the right conditions to flourish, such as nutrients, water and sunlight to support growth.

According to some researchers, Green Algae can be beneficial to plants, and we don’t like it because it is slimy and can become very smelly. We want it removed, and we want to prevent it from entering our AeroGarden unit, and if left unchecked for too long, Algae can cause some serious problems.


  • Archaeplastida – green or red algae
  • Kingdom: Plantae
  • chlorophyte green alga genus – Stigeoclouium

What kinds of Algae are common?

Cyanobacteria, freshwater algae:

  • Diatoms
  • Green algae
  • Blue-Green Algae
  • Brown algae

Large Group of Green algae what do they consist of?

  • Mesosstigmatophyceae
  • Chlorokybohyceae
  • Chlorophyta
  • Charophyta
  • Embryophyta

If you want to find out more about Green algae

How is Algae formed?

If Algae is left unchecked for too long, it can multiply and cause blooms. For this to occur, the water has to contain phosphorous, Nitrogen and sunlight; the conditions have to be perfect.

What are blooms?

Blooms are also known as “harmful algae blooms” (HABs) which can be quite harmful to humans and the ecosystem.

What nutrients that support the algae’s growth?

Green algae appear, green because it contains the same ration of chlorophyll as that of plants. Algae do not have a root system, stem or leaves. Algae go through a life cycle as a single-celled organism and are dependent on water temperature, sunlight and nutrients in the water, including pH level. If the conditions are perfect, algae will thrive; otherwise, it cannot reproduce. Algae needs nutrients in water such as

  • Nitrogen
  • Phosphorous
  • Co2

How does Green Algae survive?

Green Algae survives when the elements are right, it will grow. However, it will not grow in the dry. Mind you, I have seen algae dried up, and when we have had rain, it seems to come back, but this could be a different type of algae growing between garden footpaths.

Algae grow just like plants, it is tough and can be hard to get rid of once it establishes itself and causes issues. It intakes carbon dioxide, with nutrients and light helps produce photosynthesis in daylight. pH level rises.

During the night, the opposite effect occurs. Algae consume dissolved oxygen from the water to release carbon dioxide, which is released back into the water via respiration. So the issue is carbon dioxide creates carbonic acid, which causes a drop in pH levels. Plants begin to suffer due to lack of nutrients and oxygen in the water. 

Sometimes what we see can be beneficial fungi and not hurt our plants or prevent germination. Beneficial fungi grow when it finds the right conditions, such as on the top of seed pods, around the edge of your water container or even on top where water has spilled. 

Why do we call it beneficial fungi?

It’s called beneficial fungi because it helps the plants to uptake nutrients and moisture, known as a symbiotic relationship between the plant and fungi.

This type of fungi will eventually disappear as your plants grow. Many people don’t like the green mould forming and worry about the health issues to their plants and themselves.

What can you do?

  • Remove the dome
  • Increase airflow
  • Scrape off the mould with a cloth

Are green algae harmful?

Not all algae are harmful. It’s a natural process and is part of the aquatic food chain.

Which of the most common freshwater algae are the most harmful?

The most harmful freshwater algae are:

  • Red Tides
  • Blue-green algae
  • Cyanobacteria

They are most severe on the economy, aquatic systems, and health to humans.

If you have green, scummy or smelly water in your AeroGarden, you will need to clean it immediately.

Are algae harmful to my plants?

Algae is not harmful to your plants; it just looks yucky, slimy, green and starts to smell.

How do I prevent Algae from entering my AeroGarden?

Cover empty pod holes with aero gardens plant spacers, algae growth should be minimal. Algae needs a wet surface to grow, so keeping the body of your aerogarden as dry as possible will prevent algae from getting into your system.    

If it keeps occurring, there are some prevention methods I noticed in various comments on the Internet and include:

  • Determine where the algae are getting into your AeroGarden unit
  • Add 3% of hydrogen peroxide to 3 millilitres (ml) of water, twice a week! (A shot glass size), will not harm the roots of your plants or kill your plants in any way
  • Bleach non-perfumed ratio 1:100 about 1.3 oz. to each gallon of water
  • Algaecide control method to control the blooms. 
  • Grapefruit seed extract used incorrect dosages can kill and prevent algae growth dosage 5 to 10 drops per gallon of water.
  • Sprinkle a little cinnamon on the algae! Cinnamon prevents the algae from blooming, natural repellent, stops the spread of algae.
  • Clean and scrub the units between batches.
  • Use snails to keep the algae down!
  • Take the domes off of an hour a day.
  • Wipe around the surface with a damp clean cloth
  • Use Paper towel and gently scrape off the surface where the algae are growing.
  • Rinse container and refill with water and add nutrients

NOTE: Using chemical products can weaken your system, and the algae can regrow.

If I leave the algae, can it cause problems for my AeroGarden?

  • Build up
  • clings to surface
  • can cause problems to your pump
  • horrible decomposing smell
  • loves your plant’s nutrients
  • Oxygen levels start to drop
  • Plants can suffocate
  • Plant starts to become weak and unable to fight off pathogens
  • Impact on your pH levels in the water

Suppose it starts to smell empty the water and clean the bowl. Check the roots of your plants, and if they feel slimy or smelly, you can trim them and rinse the roots under fresh, clean water. Your roots should be white and healthy-looking, not brown

How do I Clean My AeroGarden?

  1. Empty the water of your reservoir to get rid of old water and nutrient mix.
  2. Remove pumps which may require cleaning of algae growth.
  3. Check for debris, broken roots, and algae growth on grow baskets.
  4. Wash your parts in Food Grade Hydrogen peroxide or bleach
  5. Wipe clean and re-assemble unit parts
  6. Add water and bleach or hydrogen peroxide.
  7. Run the system 5 mins to allow pipes to be cleaned
  8. Rinse the system with clean, clear water and allow the pump to run
  9. Drain, wipe down with clean towels.
  10. Refill reservoir with water, add nutrients, replace plants or add new seed pods.
  11. Cover any open holes not being used
  12. Do a triple rinse to remove all traces of bleach or hydrogen peroxide


Algae may not have had a chance to grow on your pumps, but there may be traces on your growing medium, and the grow baskets. Prevention is better. Remember that when you have beautiful rich nutrient water and LED lights, you will have a perfect environment for algae to grow. The best solution is to cut down on light exposure. It doesn’t matter which method you use for cleaning. Control is much better and limiting light exposure.

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This is a personal blog. Any views or opinions represented in this blog are personal and belong solely to the blog owner and do not represent those of people, institutions, or organisations that the owner may or may not be associated with in professional or personal capacity, unless explicitly stated. Any views or opinions are not intended to malign any religion, ethnic group, club, organisation, company, or individual.

All content provided on this blog is for informational purposes only. The owner of this blog makes no representations as to the accuracy or completeness of any information on this site or found by following any link on this site. The owner will not be liable for any errors or omissions in this information not for the availability of this information. The owner will not be liable for any losses, injuries, or damages from the display or use of this information.

If you are an AeroGarden lover or would like to become one, I would love to hear your feedback on the systems, plants you have grown or issues you have faced and success stories.

Yvonne’s fairy godmother

10 thoughts on “Green Algae is Attacking my AeroGarden: How to solve this issue

  1. Jongabriel says:

    Wow very interesting article my guy! I’m so sorry to hear that green algea is attacking your garden. Honestly, I can’t say I have too much experience with aerogardens. But, I can only imagine how big of a pain green algea can be to one. Thanks for the article! I think it could be very helpful if I ever get into this stuff. 

    • admin says:

      Thank you for stopping by and responding to my post on green algae attacking my aerogarden. It is quite easy to clean with a cloth dipped in a solution of vinegar or bleach. It just wipes off, and the vinegar and bleach prevent it coming back. I hope you do get one you will love picking fresh lettuce or herbs.

  2. Jamie says:

    Oh, this is very good to learn because I just want to go k to the whole concept of aerogardenning and I didn’t understand how it works but since you have been in it a whole, seems I can learn a lot from you just like I am doing now about how this algea can be a serious issue.

    • admin says:

      Hi Jamie thank you for reading and commenting on my post. I do have other post attached to my website for you to peruse on how to use an aerogarden. 

  3. Partha Banerjee says:

    Hi Yvonne,

    Well I certainly learned a few things today.

    Firstly, I myself, just like most inexperienced gardeners, view green algae as a menace and therefore immediately remove it.

    I actually had no idea that certain varieties can actually be beneficial to plants.

    However, as you’ve mentioned, I think many of us just think about the texture and the smell and want rid of it straight away.

    Secondly, and I now feel a little silly as your explanation makes perfect sense, but I always assumed that algae simply needed the presence of water.

    I had never considered that algae was also dependant on sunlight, but as I say, your explanation makes a lot of sense.

    Admittedly, I know I’m someone who’ll always eventually remove algae, plus your tips about grapefruit seed or cinnamon are absolutely awesome.

    I’d love to know how facts and tips like this first get discovered, LOL.

    A great article Yvonne.


    • Yvonne says:

      Hello, Partha thank you for your response. I never thought about algae either until I saw some green stuff growing. I wasn’t sure if it was okay to eat the herbs, but as it was not severe, I just wiped down the machine with a clean cloth soaked in vinegar and water. It wiped off so easily. Those tips on cinnamon are I think household ideas that someone has tried, but how they came up with the idea I’m not really too sure

      • Partha Banerjee says:

        Hey Yvonne,

        Thanks for the response.

        To be honest, I’m totally with you there – If I see algae near any herbs or edible plants I automtically think they are ruined, and in the past I would never have gone near them afterwards.

        However, judging by what you’ve said here, I’ve obviously been a little too over cautious.

        Thanks for the “vinegar” tip too, I definitely know that vinegar’s something that has many great cleaning and antibacterial properties.

        Just checked out the video too Yvonne – awesome.


        • Yvonne says:

          Thank you Partha for your comment. I’m glad you like the video and the tip on using vinegar. I think it is a better option to bleach, I never feel comfortable using bleach all the time. So long as the roots are not turning brown I believe it’s safe.

  4. Jason says:

    Hey Yvonne.

    My kids and I started an aero garden a few months ago so it is really starting to take shape. Its cold here in Europe so will be interesting to see how it goes through the winter. We have managed to keep it fairly clean so algae hasn’t been an issue but its interesting to note some of your suggested prevention tools – cinnamon, grapefruit speeds etc. Thanks for sharing.

    • Yvonne says:

      Hi Jason, thank you for stopping by and posting a response. I’m glad you have an aerogarden, and I would be interested in hearing about how you go through the winter months. Keep in contact to let me know. Thank You.

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