How to Keep Pond Water Clear Without a Filter [10 Tips]

You don’t need a filter to keep your pond water clear if you do the following:

  1. Place bundles of barley straw in the water to naturally clear it.
  2. Use an aerator to increase oxygen levels in the water.
  3. Grow beneficial aquatic plants in your pond.
  4. Stock no more than 2 small fish per 100 gallons of water.
  5. Change out 10–30% of the pond water each week.
  6. Use a pond vacuum to clean debris off the bottom of the pond every 2–3 months.
  7. Treat your pond with algae-killing beneficial bacteria.
  8. Add lava rocks or other biofilters to give beneficial bacteria a place to reproduce.
  9. Give your pond shade with a tree, small plants, or an umbrella.
  10. Clean debris out of the pond weekly.

It is not always necessary to use all of these tips to keep your pond clear, but they are all helpful. Start with the small, inexpensive tips and continue gradually adding more to your pond care routine until the water stays clear.

How to keep pond water clear without a filter

Can Fish Live in a Pond Without a Filter?

Small fish can live healthy lives in a filterless pond as long as the pond is not overstocked and is maintained regularly. The main problem with stocking fish in an unfiltered pond is that the waste produced by the fish will build up, creating an environment that smothers plants and leads to unhealthy water. To prevent this, stock 1 to 2 fish for every 100 gallons of water.

  • A few small fish can remain very healthy in a pond without a filter.
  • Know the size of your pond.
  • For every 100 gallons of water in the pond, stock 1 or 2 fish.
  • Opt for small fish like Rosy Red Minnows—koi are too big to thrive in an unfiltered pond.

If you are raising fish in a pond without a filter, do not stock large fish, such as koi. These big fish need a filter. Rosy Red Minnows are a great alternative to koi in a filterless pond. They provide a similar color at a smaller size.

10 Strategies for Keeping Pond Water Clear Without A Filter

If you’ve been having a hard time keeping the water clear in your backyard pond, use the tips from this list to correct the problem. Start with one tip, see the results, and then move to the next tip until your pond is clear.

Use Barley Straw to Clear Your Water

Barley straw is an inexpensive way to clear green pond water fast. As the barley straw decomposes, it releases a chemical compound similar to hydrogen peroxide. This naturally kills algae and keeps the water clear. Simply place one of these bales of barley straw in the water for every 1,000 gallons of water. It is best to put the bale of barley straw in a mesh bag to keep it from breaking up and making a mess. Then, simply allow it to float on the surface of the water. Replace the barley straw every 4–6 months to keep your pond clear.

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Aerate the Water

Instead of using a filter to keep your pond water clear, invest in this high-quality aerator for your pond. Aerating your pond adds dissolved oxygen to the water. This keeps the water clear by preventing algae formation. It also leads to healthier fish and plants, prevents mosquitoes from breeding in the water, and reduces bad smells produced by stagnant pond water.

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Add Beneficial Pond Plants

Pond plants work as a natural filter for your water. They use fish waste and sediment to fuel their growth. These nutrients would otherwise be stolen by harmful algae that will turn your pond murky. Water lilies, American pondweed, fanwort, water lettuce, and even beneficial reeds like cattails will lead to a healthier pond. Consider planting some in order to keep your pond clear without a filter.

Stock Fewer Fish

To maintain clear water in an unfiltered pond, make sure to stock fewer and smaller fish in the pond. Filtered ponds can support 1 fish for every 10 to 30 gallons of water. Without a filter, stock a maximum of 2 small fish per 100 gallons. 1 fish per 100 gallons is even safer. Opt for small fish. Colorful minnows are the best choice for ponds with no filter. Koi and other large species can only survive in filtered ponds. If you have too many fish in an unfiltered pond, the waste they produce will overwhelm the pond and leave it murky.

Change Your Pond Water Often

To keep pond water clear when there is no filter, you must change a portion of the pond water every week. Each week, remove 10 to 30% of the water with a bucket or a siphon hose. Then, replace the old water with fresh water. This will get rid of particles and contaminants that cloud your pond. It may seem wasteful to change the water so often, but you can use the old water to irrigate your garden or lawn.

Try a Water Vacuum

You can prevent cloudy water in a filterless pond by using this pond vacuum to clean the sediment and debris off the bottom of the pond. This will result in clear water because you are removing fish waste, dead leaves, and sediment. To maintain a clean pond, vacuum the bottom of the pond once every 2 to 3 months.

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Add Beneficial Bacteria

One reason your pond is struggling to remain clear may be due to a lack of the proper bacterial life in the water. Beneficial bacteria chokes out excess algae by consuming oxygen that would otherwise fuel the growth of algae. Follow the directions on this beneficial algae packaging to introduce more healthy bacteria to your pond. Your water will remain much clearer.

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Use a Biofilter

A biofilter isn’t a pond filtration system but it provides some of the same benefits, including clear water. Biofilters are artificial or natural objects placed in the water that provide nooks and crannies for beneficial bacteria to thrive. This bacteria then destroys algae growth, resulting in a clearer pond. Lava rocks are an excellent biofilter. So are these biofilter balls that encourage helpful bacteria populations in your pond.

Add Some Shade

Ponds that are exposed to direct sunlight all day often have murky, foul-smelling water. This is due to the fact that algae growth accelerates in high sunlight. Too much algae results in a filthy pond. Try planting a tree, reeds, or shrubs that provide shade to the pond for half the day. If you don’t want to wait for a plant to grow, try placing a large outdoor umbrella beside the pond, to give it shade in the afternoon. Your pond water will stay clear when you provide enough shade.

Clean Debris Out of Your Pond

Keeping your pond water clean of debris, fallen leaves, dead plants, and grass clippings will lead to clear water and healthy aquatic life. If you notice any debris floating in the pond, use a pool skimmer to clean it off the surface of the water. Allowing debris to sit in the water will cause it to rot and break down. This can turn a healthy pond dark and clouded. So, a debris-free pond is a clear pond.

Will Baking Soda Clear Pond Water?

Baking soda is not useful for turning murky pond water clear. Even large amounts of baking soda won’t kill off much algae or improve the water quality, even in a small pond. So, it’s best not to use your time and money on a baking soda treatment. In a larger pond, baking soda will have no noticeable effect.

  • Baking soda does not turn murky pond water clear.
  • Bad-smelling pond water will not be improved by adding baking soda.
  • A small bale of barley straw can naturally turn pond water clear without harming fish.
  • Consider adding beneficial bacteria to algae-choked pond water.

You will get much better results by treating your water with beneficial bacteria or bales of barley straw. These natural choices deoxygenate the water safely to kill off algae without harming fish. Since natural pond-clearing products are inexpensive, there’s no need to try out baking soda.

How Do You Clear Pond Water Without a Filter?

You can keep a filterless pond clear by placing bales of barley straw in the water to naturally kill algae. You can also add an aerator to the pond for healthier fish and plants, as well as less algae and odor. To naturally boost water clarity, grow aquatic plants in your pond. Changing 10 to 30% of the water each week helps maintain a clear pond. It is also very helpful to use a pond vacuum to remove buildup from the pond bottom every 2 to 3 months. Beneficial bacteria is essential to keeping pond water clear. Add store-bought beneficial bacteria as well as a “biofilter” that gives the bacteria a breeding ground. Make sure your pond gets shade for half the day to encourage clearer water. Always clean debris out of the pond promptly to prevent the water from turning cloudy.

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