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How to Remove Algae from Ponds Without Hurting Fish: 8 Tips & Methods
By Lindsey Stanton
Updated on
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Algae in a pond can be a massive pain to try to get rid of, but it’s usually necessary to get rid of it. Low levels of algae aren’t a problem most of the time, but large amounts of algae can become dangerous to your aquatic animals, and they can take nutrients from the water that your plants need to grow. Algae is a great source of oxygen during the day, but at night, it often begins to pull large amounts of oxygen from the water, which can suffocate the animals in the pond. Finding ways to get rid of algae safely can be difficult to achieve, so here are the things you need to know about removing algae from your pond without hurting your fish.
The 8 Tips to Remove Algae from Your Pond
1. Remove the Algae
Algae can be manually removed from the pond with a garden or pond rake. It’s important to be extremely careful to not damage plants, animals, or your pond’s liner when you’re doing this. Removing as much visible algae as possible will make getting it under control and removing what remains much easier.
Image Credit: pfluegler-photo, Shutterstock
2. Remove Debris from the Water
While you’re raking the pond, go ahead and gently remove debris that has made its way into the pond. This includes leaf litter, grass clippings, and anything else that may be adding nutrients to the water or creating a healthy environment for algae.
3. Add Rooted Plants
The addition of rooted plants to your pond will help decrease the nutrients in the water. If you have fish, they are constantly releasing waste products into the water that plants use for energy. The more healthy, growing plants you have, the more nutrients are pulled from the water. The removal of these nutrients will decrease what the algae can use for energy to grow and reproduce.
4. Add Floating Plants
Floating plants exclusively pull nutrients from the water column, as opposed to rooted plants, which often pull from the water column and the substrate. Floating plants, like water lettuce and water wisteria, don’t just pull nutrients from the water, but they also create shade. Algae needs light to grow, so the more shade you’re able to create in your pond, the less algae will be able to grow.
5. Add Barley Straw
Barley straw is placed near the surface of a pond and as it breaks down, it releases byproducts that help maintain water clarity. Typically, a single small bale treats around 1,000 gallons of water for up to 6 months. Barley straw can be used to prevent or eradicate algae without adding chemical algaecides to the water.
Image Credit: bernswaelz, Pixabay
6. Support Beneficial Bacteria Colonization
A healthy pond has healthy levels of beneficial bacteria, which help break down waste products from fish. As waste products are broken down and removed from the water, the algae lose the extra nutrients that would be in the water otherwise. Beneficial bacteria can be purchased in liquid or tablet form, but it will also develop on its own over time, living on surfaces and within the pond’s filtration system.
7. Try a UV Light
Image credit: TIPAKORN MAKORNSEN, Shutterstock
The addition of an in-line UV light can safely and effectively kill free-floating algae in your pond. This won’t work for algae that is growing on surfaces already, though. UV lights can be purchased independently of other equipment, but many pond pumps also include a built-in UV light.
8. Use Algaecide
Sometimes, chemical algaecides are necessary to quickly eliminate the algae in your pond. If overdosed, these can be dangerous to the health of your aquatic plants and animals, so following instructions carefully is important. Algaecides rapidly kill off algae, which can decrease water oxygen levels to dangerously low levels, so it’s important to ensure that all filtration and aeration is running around the clock when using chemical algaecides. As the algae dies, it will need to be removed from the pond manually.
This two-pack of barley straw bales treats up to 2,000 gallons of pond water. Each bale lasts up to 6 months and can safely eliminate and prevent algae in your pond.
Barley straw does require some babysitting because the bales won’t work if they sink to the bottom of the pond. Using this barley straw extract can help you get the benefits of barley straw without the extra work.
This floating weed lake rake is a great option for raking algae from your pond. It’s not too sharp and the floating aspect means that if your rake gets away from you, you won’t be trying to fish it from the bottom of the pond.
This is a fantastic in-line UV pond clarifier. It can be installed in the tubing for your pond’s filtration system, helping to kill the free-floating algae in the water as it runs through the filtration system.
This chemical algaecide is possibly the best on the market. It’s safe and effective when used properly. Within three days, the algae in your pond should be dead or dying. This can be used as a preventive algaecide as well.
Formulated to help remove potentially dangerous debris and organic sludge
Registered with the Environmental Protection Agency
Available in three sizes
Cons
Algae may grow bak after several applications
This is a bacterial algaecide, which means that it works to kill the algae in your pond while simultaneously supporting the beneficial bacteria colonies. It is safe for pond life and effective against algae.
Safe for most pond fish and live ornamental plants
Cons
Not safe for use with snails, shrimp and other crustaceans
Another great chemical algaecide, this product stops algae growth in your pond and works to kill the existing algae. If used properly, it is safe for pond life.
8. Microbe-Lift PL Pond & Lagoon Bacteria Water Treatment
Treatment is not intended to be used with saltwater aquariums
If your pond needs a beneficial bacteria boost, then this product will help you achieve that. The bacteria in it serves as a bacterial algaecide and a boost to your beneficial bacteria colonies.
Conclusion
Killing and removing the algae from your pond can be a multi-step process. If things have already gotten out of hand, then you’ve got your work cut out for you, but there are a ton of products and methods you can use to kill, remove, and prevent algae in your pond. It’s important to stay on top of things, considering algae prevention and removal to be one aspect of your routine pond care. This will keep your fish safe and will prevent a lot of extra work for you.
Featured Image Credit: Paula Cobleigh, Shutterstock