How To Get Rid Of Algae In A Large Pond {The Top 3 Essential Methods Explained}

Are you wondering how to get rid of algae in farm ponds, lakes and large fish ponds? Do you know that the methods used in backyard ponds may not work for you? In this article, we’ll go through what it takes to get clear algae from larger bodies of water.

How To Get Rid Of Algae In A Large Pond. Invest in an aerator and run it all year round. Buy plenty of beneficial bacteria and treat the water once every 2 weeks. Apply aquatic sun blocker or pond dye and stay on top of clearing debris with a lake rake or pond skimmer. 

What Makes A Larger Pond Different From A Small Pond For Getting Rid of Algae?

A large pond would be over 50 feet in size. A 50 by 50 foot pond is going to be a tougher task to maintain and clear algae compared to a koi pond in a backyard. Your tools and supplies needed will differ.

Consider how hard it would be to use a filter for a body of water this large in size. There must be another approach other than buying a filter and placing it in the pond. Aeration is going to be the best method, but this task is going to need much more than that.

What Do I Need To Get Rid of Algae In A Large Pond?

  • beneficial bacteria
  • aerator
  • skimmer
  • lake rake
  • aquatic sun blocker or pond dye
  • deicer for the winter

We’re looking to break down organic matter like leaves, dead fish and plants that will increase the nitrites which algae feed on. Treating the large pond with beneficial bacteria is a great start to staying proactive before matters get worse.

Once the algae has set in thick, tools like aerators, skimmers or a lake rake will come in handy to do the dirty work. Aquatic sun blockers or pond dyes on the market help shield the pond by reflecting sunlight to control algae overgrowth.

How Does Beneficial Bacteria Help Get Rid of Algae?

Larger ponds will pack in many unwanted nutrients that will become food for algae. Consider all the dead matter and mulch turning into an active compost heap in the water. Beneficial bacteria will compete with algae to consume these nutrients.

The healthy bacteria breaks this unwanted debris up and clears up the muck including parasites and unhealthy bacteria. They starve out the algae from obtaining the nutrients in that muck.

A large pond should be treated with beneficial bacteria once every 2 weeks at the minimum, especially when the water temperature rises above 50°F.  This is when algae thrives so introducing a fierce competitor that will break down the nutrients before the algae can consume them is important.

How Does Aeration Reduce Algae In Large Ponds?

Aeration is useful for providing more oxygen and preventing the large pond from being stagnant. Not only does algae love stagnant water, mosquitos will as well. Avoid this mess with proper aeration. Warm and shallow water with contain plenty of algae that is filamentous which looks like pond scum.

Aeration needs to run all year round without a day off in a large pond. A new aerator should not be hard to set up. Attach the air diffuser to the tubing and connect that to the compressor. Plug it in and keep it running all year round.

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Should I Use A Sun Blocker Or Pond Dye To Get Rid Of Algae?

An aquatic sun blocker will prevent the algae from getting enough sunlight to grow. It reflects the sunlight without harming the pond life including the fish who call this environment their home.

These products marketed as sun blockers or pond dyes are not full of chemicals that are found in algaecide or herbicide. They won’t kill the life in the pond or the algae, but they’ll prevent unwanted algae from growing.

My Large Pond Is Clear. Do I Need To Treat It For Algae?

Most people who look at a relatively clear large pond don’t realize the amount of activity going on inside it. The organic matter in the pond is collecting at the bottom and the water is hiding it. Sooner or later the balance of the pond’s ecosystem will be out of whack.

Pond life will become stressful and ugly before you know it. The fish will get stressed the sludge and the pond scum will start to rise. Suddenly a bunch of dead fish rise to the surface too and you will wonder what happened.

Rely on these three helpers to make sure this doesn’t happen.

  • Beneficial Bacteria
  • Aeration
  • Aquatic Sun Blocker

Should I Use A Lake Rake On My Pond?

The final step is on you to physically clean up debris that is floating at the surface or deeper in the pond with a rake or skimmer. You can actively get rid of fallen leaves, cattails and dead plants. It may not sound like fun, but you can get some help from friends by enticing them with some food and drinks.

If you haven’t dumped chemicals in your pond, the mulch you collect with a lake rake or skimmer can be added to an actual compost heap for future use.

Will Algaecides Get Rid Of Algae In Large Ponds?

Algaecides and herbicides contain harsh chemicals that will certainly kill algae. They will also kill a lot of healthy bacteria and possibly the life that lives in your pond as well. This is a quick fix solution, but you will need lots of it to cover your pond and turn it into a chemical dump.

We’re being negative towards chemicals in algaecides because there’s nothing in it that will prevent the algae from coming back. Sure, you’ve killed off your algae and harmed the ecosystem of your pond, but the result of having it cleared is only temporary.


Using beneficial bacteria, an aerator and sun blocker solutions are going to work out better for you and this large body of water in the end. Your fish and the ecosystem as a whole will thank you for it.

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.

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