The Best Clear Pond Water Treatments (Top Methods)

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The Best Clear Pond Water Treatments 2022 (Ways to Get Clear Pond Water) 

Note: You should regularly test your water quality before, during, and after any treatment to ensure water condition remains within safe parameters. Testing water quality can also help you identify any underlying issues which may be causing the reduction in clarity. 

1) Activated Carbon & Zeolite Treatments

Recommended for: Removing tannin, dyes, brown water, cloudy water, chlorine, fertilizers, medicine, and heavy organic pollutants.

What is it?

activated carbon to clean pond water
Activated carbon is very useful in removing heavy pollutants that biological and mechanical media cannot remove.

Activated carbon is a very popular method of providing a third stage of water filtration, sometimes called “chemical filtration”, on top of regular mechanical and biological media. Activated carbon, or activated charcoal, works via a process called “adsorption“, which causes organic molecules to stick to the carbons surface from the surrounding water. This strong attraction of particles is why activated carbon is so effective at neutralizing a wide range of organic pollutants, including those that may cause unclear water, such as fertilizers and tannins. Biological filter media cannot break down these heavy organic substances, and in some cases the only way to remove the effectively is with carbon-based filter treatments. Zeolite functions in a very similar way, neutralizing molecules via adsorption, but works best for removing fertilizers or inorganic substances, such as perfumes and pesticides.

Why use it?

Activated carbon is an effective and safe method for neutralizing a range of organic substances which can cause water discolouration, including tannin, proteins, and fertilizers. The most common cause of brown water problems is the leeching of organic color, called tannin, into the surrounding water from decomposing organic matter (i.e., leaves). Although carbon can’t remove the debris itself, it can help improve clarity by reducing the free-swimming tannin which gives the water a brownish appearance. Likewise, cloudy or milky water is often caused by excess fertilizer substances, such as phosphates, or excess proteins which can leech from fish feeding. Both these types of substances are organic in nature and activated carbon works very well for reducing the quantity in water with continued treatment.

Similarly to activated carbon, zeolite is also an effective treatment for removing a range of pollutants and works via the same process of adsorption. Zeolite is particularly effective at removing fertilizers, such as phosphates an nitrates, which can cause milky and cloudy water. However, zeolite is better suited to the removal of inorganic compounds, and can also cause some issues with water chemistry due to how it interacts with molecules. For this reason, we’d recommend activated carbon over zeolite in most situations, especially if your problem is tannin-laden (brown) or cloudy water.

2) Beneficial Bacteria Treatments

Recommended for: Clearing murky water, improving water quality, reducing organic waste (ammonia), and enchaining bio-filtration.

What is it?

beneficial bacteria clears dirty water
Beneficial bacteria breaks down waste and harmful substances which can be a cause of dirty water.

Beneficial bacteria that lives throughout your pond and filter box has the important job of breaking down harmful waste substances, such as ammonia and nitrites, into less harmful compounds – a process called the nitrogen cycle. However, under certain conditions beneficial bacteria may not be able to keep up with a ponds waste production, or there may simply be not enough bacteria present to begin with – such as with new ponds. When this happens, harmful substances will begin to rise alongside debris, waste, and pond sludge which can causes issues with both water quality and clarity over time. If you’re noticing your water is looking a little murky, or your fish seem unhappy, we recommend performing a wide range water test to determine your current water quality. If your tests happen to come back with high readings of ammonia, nitrites, or nitrates, it’s safe to assume your biological filtration may be struggling and could use some help. Beneficial bacteria treatments are a highly effective method of giving them a boost!

Why use it?

Although water quality and water clarity (clearness) are not always linked, a reduction in clarity can sometimes indicate a growing problem with water quality, such as excess waste substances. Since the majority of substance breakdown takes place within your highly optimized biological-media, one of the easiest ways to enhance water filtration is to add a concentrated beneficial bacteria supplement straight to the filter box. Beneficial bacteria treatments contain the same strains found naturally in ponds, but in highly concentrated doses, and often alongside other helpful ingredients, such as pro-biotic enzymes. More beneficial bacteria will help with the breakdown of waste, which should also lead to a reduction in ammonia and nitrites which can cause issues with both water quality and clarity.

Beneficial bacteria is aerobic in nature, meaning it requires a highly oxygenated environment to perform its job effectively. If you already have a large amount of waste, you may also have low dissolved oxygen, so we first recommend a heavy clean of sludge and muck before adding beneficial bacteria. This includes removing sludge from the pond floor, and also cleaning any muck from inside the filter media as this reduces oxygen and nutrient exchange for bacteria living inside.

3) UV Clarification Treatments

Recommended for: Clearing green pond water caused by free-swimming algae, and to reduce harmful bacteria strains.

What is it?

how to get clear pond water with UV clarifiers
Clarifiers are a safe and effective way to treat free-swimming algae that causes green pond water.

Unlike other clear water treatment options here, a UV clarifier doesn’t come in a bottle; it’s something you’ll need to manually add to your plumbing framework! As the name suggests, these range of devices make use of ultra violet light to sterilize water from harmful bacterium and free-swimming algae particles. You’ll need a pump to get the device working, which then pushes water through the main chamber which contains a UV light in various degrees of strength. As the water passes through the light, any pathogens, bacteria, or algae particles are destroyed at the cellular-level and eventually deposited within your filter media or the pond floor. For large ponds or heavy stocked koi ponds a UV strength of 25 watts+ is recommended, with a 5 watt to 25 watt range being fine for smaller ponds or lighter fish stocks.

Why use it?

UV clarification is the single most effective method of treating green pond water caused by free-swimming algae particles, especially if you have fish. Unlike chemical algaecide which can be very dangerous to the ecosystem, UV clarifiers don’t interfere with anything apart from the water which flows through them, making them a great choice for fish stocked ponds. In-fact, many koi and goldfish keepers will choose to run their UV clarifiers all year, even when there is no sign of green water problems. This is because the UV treatment which destroys algae particles also destroys free-swimming bacterium which can cause both disease and sickness in koi and goldfish. Since the majority of a pond’s beneficial bacteria is located within filter media or on the pond liner, the UV light will have little to no impact on their populations and only target pathogens that free-swim within the pond system.

In terms of green pond water, a UV Clarifier will be able to clear a pond within a week of constant use – faster if you have a fast flowing pump and high wattage clarifier. Since dead algae will start to decompose after its has been destroyed, you’ll need to keep on top of cleaning during the treatment, which includes removing bottom muck and cleaning the filter media.

4) Barley Straw Treatments 

Recommended for: Long term control of green water, string algae, and blanket weed and preventing re-growth in future.

What is it?

controlling algae with barley straw
Barley straw works as a long-term algae control method, preventing the growth of both green algae and string algae.

Barley is a widely used cereal grain found in many commercial food products across the world, as well as being a major component of many popular beer beverages. Surprisingly, barley straw has also been used for centuries as a natural algae deterrent in fresh bodies of water, including wells, lakes, and ponds. Barley by itself cannot stop algae from growing, but can produce potent substances during decomposition which work as natural algaecides. After placing barley in your pond it will slowly become waterlogged and sink to the bottom with the rest of your bottom sludge. As it slowly decomposes it will begin to release humic acid into the surrounding water; a natural product of the decomposition of certain organic material. As the humic acid enters the pond it reacts with both oxygen and sunlight, forming a super-oxide radical which leads to hydrogen peroxide. Hydrogen peroxide is a powerful algae killer, and is produced in a low enough volume from barley straw to be safe for the ecosystem, but still remain a highly effective algae deterrent.

Why use it?

Although UV clarifiers can remove green-swimming algae very effectively, they will have no effect on the growth of larger types of algae, such as string algae and blanketweed. As well as this, for those of you wanting to save money on your electricity bill, running a UV Clarifier 24/7 likely isn’t the most viable option. Barley straw extract isn’t designed to remove an algae bloom already present, and it should never be used for this purpose as it can make conditions worse. However, it’s a very effective long-term deterrent, and can be added after an algae bloom has been treated with other methods (UV clarifier) to prevent the re-growth of algae in future. Since the mechanism of action requires decomposition to occur, monitoring water quality closely and providing plenty of aeration is important when using barley in ponds.

5) Water Changes & De-chlorinators

Recommended for: Reducing tannin, muddy water, dirty water, ammonia, nitrites, and chlorine via de-chlorination products.

What is it?

why should pond water be dechlorinated
Mains water should be de-chlorinated during water changes to prevent swings in water quality and stress to fish.

A water change is simply the act of removing a certain amount of pond water (usually 10-25%), and replacing it with fresh water from your mains supply. This can be carried out when you have problems with clarity, or as a regular part of your pond keeping routine to keep harmful substances in check. However, since mains water contains a heavy dose of both chlorine and chloramine, it should first be dechlorinated before the water is added to your main pond system. Both chlorine and chloramine are potent disinfectants, and will cause severe burns to the gills of fish, as well as kill off your beneficial bacteria populations. These substances can be removed with a liquid dechlorinator product, carbon hose attachments, or activated carbon within your filter box.

Why use it?

Although water changes are unlikely to resolve the root cause of unclear water, they can help improve overall water clarity while you work towards a solution. For example, a water change will be able to reduce a certain amount of tannin (organic color) in water which may be causing a brown appearance, but it can’t solve the  problem coming back. In this case the brown color is likely caused by decaying leaves and debris on the pond floor leeching tannin, so unless you also take care of the decomposing matter, the color will simply return! However, in some instances water changes can still be very useful, such as for heavy stocked ponds where it becomes very difficult to keep on top of waste and substance levels. Fish produce A LOT of constant waste, so many fish keepers choose to perform regular water changes to reduce harmful ammonia and nitrites alongside their natural beneficial bacteria and bio-filtration.

If you’re considering performing water changes, the amount of water you replace should always be kept as minimal as possible, and the water should always be dechlorinated beforehand. Water changes are a good “quick fix” to quickly improve the clearness of water, but should be carried out alongside other methods to resolve any underlying problems.

6) Polywool (Ultra Fine) Filter Media

Recommended for: Removing tannin (organic color), sediment, and free-swimming debris that can cause muddy or brown water.

What is it?

poly wool filter wool helps remove small particles from water
Fine filter media, such as filter wool, can help remove smaller particles contributing to muddy water.

Regular mechanical filter media is useful for removing larger free-swimming debris and matter, but often can’t remove very fine particles which could be causing issues with clarity. Polywool, wool, or floss filter media is designed to trap these tiny particles and can help improve the clearness of water. They’re very common in the aquarium hobby for keeping water clear, and can also be used in ponds inside the filter box or under the filter out-take for reducing the cause of water discolouration. Most products will come in large rolls which can be cut to size to fit your filtration system, and also various sizes of thickness for optimal debris removal.

Why use it?

Using an ultra fine media material is a useful way of removing very small particles from the water without the need for water changes or chemical treatments. The material is designed with very small porosity so can trap even the finest of free-swimming debris, and will also work to absorb a large amount of tannin which causes brown water problems. If you have a non-pressurized filter it can be added to your filter box alongside your regular media, but may need to be added externally in front of the out-take for pressurized filters as the media will greatly reduce water flow and increase pressure. As the materials are chemically inert, there should be no problems with water quality and it can be used safely in ponds with fish. A useful option for adding extra polish to ponds or to help clear dirty water and tannin!

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