The Best Pond UV Clarifiers of 2021


An outdoor pond is one of the best ways to elevate the aesthetics of your garden. Unfortunately, ponds are more challenging to maintain than ordinary aquariums. A very common issue about outdoor ponds is the growth and proliferation of algae. These microorganisms can turn pond water into a greenish mess that it would be impossible to enjoy the view of Koi and other colorful fish. Unchecked algal growth can also make the pond unhealthy for your fish. Pond UV clarifiers solve these issues. In this article, we’ll share with you 7 of the best pond UV clarifiers on the market.

What is the Best Pond UV Clarifier

See also:

Top 7 Best Pond UV Clarifiers Reviews

1. TotalPond UV Pond Clarifier


TotalPond is perfect for homeowners who have ponds that max out at 2,000 gallons. The UV element is durable that it only requires replacement every 11 to 12 months. The device is very easy to install and can fit to most water fittings, including ½-, ¾-, and 1- inch tubing. There is an indicator light that eliminates guesswork whether the unit is operational or not.

This UV pond clarifier works to reduce algae and bacteria in pond water. It allows you to enjoy your pond fish a lot better, while also maintaining water quality. Unfortunately, it often takes a few weeks of continuous operation before you see noticeable results.

Regardless, the TotalPond UV Pond Clarifier works like a charm.


  • Good for large ponds
  • Lasts up to 11 months
  • With indicator lights
  • Works with major water fittings
  • Easy to install


  • Takes some time to notice results

2. TetraPond GreenFree UV Clarifier for Clean Ponds


You’ll never go wrong with Tetra products. It is one of the trustworthy brands when it comes to aquatics pet supplies, including UV clarifiers. The brand’s GreenFree UV Clarifier is one of the most popular devices on the market. It can treat up to 1,800 gallons of water and its UV element can last up to 11 months.

GreenFree is easy to install because of the addition of three sizes of adapters. Its green-colored casing should also make it easy to hide the device in the vegetation surrounding your pond. While the unit can begin clarifying pond water in as fast as 5 days, the results were far from consistent.

Despite this, the TetraPond GreenFree remains a good UV clarifier choice for pond owners.


  • Efficient in keeping pond water clear
  • Easy to install
  • Durable UV element
  • Comes with tubing adapters
  • Fast results 


  • Inconsistent results

3. Jebao Submersible Pond UV Filter


Pond owners who prefer a submersible unit should always get the Jebao UFP-2000 System. This is not your ordinary submersible UV clarifier. It does not only kill bacteria and algae. It also gets rid of viruses and protozoa. This provides a healthier environment for your pond fish, while also making water as clear as possible.

The UFP-2000 has a UV element that can last up to 12 months. You will also never have to worry about installing a mechanical and biological filter because the Jebao already has these elements. The only issue is that it takes about 2 weeks before you notice your pond water clearing up.

The Jebao UFP-2000 Submersible Pond UV Filter is the best sterilizer-filter combination you can ever get.


  • Works as a UV sterilizer
  • Comes with fountain features
  • Combination of sterilizer and filter
  • Fully submersible design
  • Powerful UV treatment


  • Takes a long time to clarify water

4. SUN Aquarium UV Clarifier


With its unbelievable 9,250-gallon capacity, the SUN Aquarium UV Clarifier is just the kind of device for people who own large decorative ponds. It does an excellent job keeping algal growth at bay, while also improving the overall quality of water for your pond fish.

This UV clarifier features a UV element that can last up to 11 months. SUN already includes adapter fittings to make installation a breeze. Maintaining this UV clarifier does not entail a lot of elbow grease, too. The only downside to this product is that you will need to protect it against the sun’s rays. The casing degrades easily.

The SUN Aquarium UV Clarifier remains a good buy, especially for those with large garden ponds.


  • Large capacity clarifier
  • Durable UV element
  • Comes with 4 sizes of adapters
  • Easy to install
  • Durable construction


  • Requires protection against natural UV light

5. Jebao STU Stainless Steel UVC Clarifier


One of Jebao’s signature offerings is the STU Stainless Steel UVC Clarifier. This is a device that offers up to 35% greater UV treatment efficiency than other clarifiers on the market. Its design is perfect for ponds as large as 8,000 gallons. The addition of a stainless-steel interior amplifies the algae-killing capabilities of its UV element.

While the Jebao STU is very easy to install, you will need to unleash your creative spirit. Its stainless-steel body requires creativity in blending it with the rest of the outdoor pond landscape.

Nevertheless, the Jebao STU Stainless Steel UVC Clarifier is perfect for homes with large ponds. It is also ideal for those whose who want efficiency over anything else. It is a very durable unit, too.


  • Large capacity UV clarifier
  • Long-lasting UV element
  • More efficient UV treatment
  • Easy to clean and maintain
  • Durable construction


  • Requires creativity to install

6. Pondmaster Ultra Violet Light Pond Water Clarifier



Pondmaster’s Ultra Violet Light Pond Water Clarifier is an exciting device for homeowners with medium-sized outdoor ponds. The clarifier can handle up to 6,000 gallons of water without impeding adequate water flow. It works well with very powerful pumps to help clear your pond of algae and bacteria.

What makes the Pondmaster quite unique is its use of a vortex flow design. This feature allows the clarifier to increase the exposure of water to UV light, ensuring greater efficiency. Unfortunately, the Pondmaster is quite big. It measures 23.5 inches long and 4 inches in diameter, which can be tricky to install if you’re not creative enough.

The Pondmaster UV Pond Clarifier is still a good choice. It clears water of algae to keep your pond as healthy as possible.


  • Submersible clarifier design
  • Good for medium-sized ponds
  • Unique design for better UV treatment efficiency
  • Easy to install
  • Durable


  • Quite big

7. Aquagarden Fountain Pump 5-in-1 for Clear Beautiful Ponds


If you’re just starting with your outdoor pond, we recommend the Aquagarden Fountain Pump. This has everything you need to create a masterpiece. It has two kinds of filters – biological and mechanical – and a powerful pump. The integrated UV clarifier also works like a charm in keeping your pond water as clear as possible. On top of that, there is a decorative LED light to make your pond stand out at night. And when you run the fountain, it should be an awesome sight.

The only downside is that the installation instructions are not that clear. However, once installed, the Aquagarden Fountain Pump can be the most amazing 5-in-1 product you will ever buy for your pond.


  • A complete pond system
  • Comes with mechanical and biological filters
  • Features a fountain and LED light
  • Powerful pump
  • Good for small-sized ponds


  • Unclear installation instructions

Pond UV Clarifiers Buying Guide

There are a few items that you should include in your checklist when buying a pond UV clarifier.

Water Capacity

A good UV clarifier should be able to accommodate the volume of water in your pond. Always pick a pond UV clarifier that has at least 20% greater capacity than your pond. For example, if your pond contains 2,000 gallons, then it would be best to get a UV clarifier that can accommodate up to 2,400 gallons. Most people will also get a 2,000-gallon unit. It is best to observe some allowance.

Service Life of UV Element

The water clarifying ability of a UV clarifier lies in the service life span of its UV element. This is the second most important consideration. A device with a longer UV element service life is better than one with a shorter service life. Take note that the rating is often in hours. You will have to do a little math to determine the service life of the product.

Submersible or Out-of-Water?

Most UV clarifiers have an out-of-water design. These devices should never be submerged. You will have to take note of your pond design to check how you can best install this type of device. If you want a unit that you can install in your pond, then choose a submersible device.

Standalone or Combo?

If your pond already has an existing mechanical or biological filter, then it is best to buy a standalone UV clarifier. This will also have an impact on how you install the device. Ponds with biological filters should always have the UV clarifier after the filter. Ponds with mechanical filtration mechanisms should always have the UV clarifier before the filter. If you don’t have a filter yet, then a clarifier-filter combo can be a good choice.

What is a Pond UV Clarifier?


Pond UV clarifiers are small devices that connect to the water filtration system of ponds. It inactivates single-celled organisms that can turn pond water into a murky green mess if these organisms can thrive. The resulting water clarity allows you to enjoy watching your fish and other aquatic life forms.

How Does a Pond UV Clarifier Work?

This small device comes with a very simple design. It consists of a chamber and several ports to connect it to the pond or aquarium’s water filtration system. Depending on the manufacturer, the UV clarifier gets installed before or after the water filter.

The chamber contains an element that discharges ultraviolet light. Ultraviolet light prevents single-celled microorganisms from multiplying. At the same time, UV light promotes the adhesion of these microorganisms with each other. They form into clumps, allowing the filter to do its part.

So, how exactly does it work? Water filled with algae enters the chamber of the UV clarifier. This promotes clumping of the algae, while robbing them of their ability to multiply. The water filled with clumped algae passes out of the clarifier and goes to the filter. The clumps of algae get filtered, resulting in a clearer and algae-free water coming out of the filtration system.

Types of Pond UV Clarifiers

There are two basic types of pond UV clarifiers. These include the standalone UV clarifier and a UV clarifier-filter combo. There is another device that some people consider as a UV clarifier. However, its mechanism of action is more appropriate for more aggressive water treatment.

Standalone UV Clarifier

Many of the UV clarifiers you will see on the market come as standalone units. These are ideal for pond and aquarium owners who already have an existing fish tank filtration system. All you need to do is to connect the clarifier anywhere along the filtration line and let the device do its job. Majority of these devices are not submersible.

UV Clarifier-Filter Combo

If you are just starting with your pond or fish tank, your best choice will be a UV clarifier-filter combo. These are devices that offer two different functions in a single design. There is a component that can filter algae and other water impurities. There is also the component that inactivates the microorganisms by exposing them to UV light. Combo clarifier-filters are more practical than standalone units. However, they are less efficient when it comes to inactivating algae.

UV Sterilizer

This device is a lot like a standalone UV clarifier. The only difference is that water passes through the UV clarifying chamber at a much slower rate. This exposes microorganisms to UV light for an extended period. This is perfect for people who may also want to kill certain viruses, protozoa, and bacteria in pond water.

Why Do You Need Pond UV Clarifier?

If you want a pond that has more aquatic plants and only a handful of fish species, then there is no need for a UV clarifier. Aquatic plants can use fish wastes and prevent algae from thriving.

However, if you are going to create a pond where Koi and other colorful tropical fish can thrive, then a pond UV clarifier is a must. The colorful nature of Koi warrants the use of aquatic plants sparingly as possible. This will allow you to showcase your Koi. Having too many aquatic plants in your Koi pond will give the fish plenty of options to hide.

The problem is that Koi do excrete a lot, too. Since the pond does not contain that many aquatic plants, the growth and proliferation of algae are certain. This can turn the pond water into a pea soup kind of green. If the algal growth is unchecked, they consume the oxygen that is supposed to be for your fish. Algae can also block sunlight, which can also have a negative effect on your fish and aquatic plants.

You will need a pond UV clarifier to prevent algal growth and improve the living conditions for your fish and plants.

Frequently Asked Questions


How do you set up a UV pond clarifier with a pump?

Manufacturers of pond UV clarifiers have different ways of setting up their products. It is best to check the manual that came with your purchase. In most cases, you connect a tube from the pump to the inlet port of the UV clarifier. You can then connect another tube from the outlet port of the UV clarifier to the mechanical filter of your pond. If you are using a biological filter, it is ideal to put the UV clarifier after the biological filter. This can help prevent clogging your biological filter with algal clumps.

How often should you change your pond UV clarifier?

Everything depends on the rated capacity of your pond UV clarifier. You should always check the service life span of the UV bulb. If it says 8,000 hours, then you should keep track of the number of hours that your pond filtration system is running. If it is running 24/7, then an 8,000-hour UV bulb should be good for about 333 days. It would be safe to assume that you need to replace your pond UV clarifier every 11 or 12 months.

What size UV pond clarifier for my pond?

The size of UV pond clarifier you will choose depends on the capacity of your pond. Manufacturers often rate their products according to the capacity of ponds and fish tanks. If your pond can accommodate 1,000 gallons, then you should pick a UV clarifier with a 1,000-gallon capacity. However, we do recommend getting a unit with a substantially higher rating. A good rule of thumb is to get a product with a maximum capacity that is at least 20% more than your actual pond capacity. As such, a 1.200-gallon unit would be more ideal for a 1,000-gallon pond.

Where to buy pond UV clarifier?

Amazon is always a good place to buy anything, including a pond UV clarifier. The main advantage is that you get to choose from many products. You also get to read reviews that can help you decide whether a product is good for your pond or not. Other e-commerce platforms can also provide such products. These can include Petco, eBay, Chewy, and others. If you prefer a physical store, then you should check your local aquatics hobby supplies store. Some pet shops may also carry a limited selection of UV clarifiers.


A good UV clarifier for ponds has a good water capacity and has a long-lasting UV element that can minimize frequent replacement of the UV clarifier. You can pick a submersible or an out-of-water unit, depending on your pond landscaping requirements. Hopefully, you have already picked one from our list of the 7 best pond UV clarifiers. If not, then you can always take the different pointers in our simplified buying guide for consideration. You can then start shopping for the best UV clarifier and getting ready to beautify your landscape with amazing and colorful Koi and other tropical pond fish.

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