The Best UV Sterilizers for Freshwater and Saltwater Aquarium in 2021

  • By:

    Vicki Smirnova
    Vicki Smirnova

    Author: Vicki Smirnova

    Vicki Smirnova is a professional writer and editor who adores animals and helps readers get along well with their pets. She has been working in digital media for more than 5 years and has great experience writing content about lifestyle, including pets. Vicki specializes in dog health and nutrition, cat feeding, dog training. She is an aquarium lover and is passionate to write about fish care at home. Also, Vicki headed several websites and worked as a news editor.

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  • Updated on: 02/18/2021

A UV sterilizer is a device that serves to disinfect water from bacteria, fungi, viruses, algae, and protozoa, many of which are pathogenic and pose a direct threat to the health and life of aquatic inhabitants. Ultraviolet radiation (UV rays, UV radiation) is electromagnetic radiation that occupies the spectral range between visible and x-ray radiation.

This device allows you to control the number of pathogens of many aquaria and pond fish diseases due to the treatment of water with harsh ultraviolet irradiation. The principle of UV operation is that water from the aquarium under pressure created by the pump passes through the filter and is fed to the sterilizer, which is usually located outside the aquarium. Inside the sterilizer, the water is treated with an ultraviolet lamp and comes out the opposite side of the water intake, again entering the aquarium. This cycle is continuously performed [1]. It works in conjunction with a filtration system – the UV sterilizer reduces the factors affecting the fish’s immune system

aquarium uv sterilizer review

If you overfeed the fish in the water, the mass of free organic matter increases sharply – the remains of uneaten food and metabolic products of fish and other hydrations. Free-floating bacteria in the water column, including pathogenic ones that are dangerous for fish, begin to decompose and multiply organic matter directly in the water. Very soon, the amount of pathogenic bacteria can reach a critical point, after which the fish’s immune system can no longer protect the body from the effects of negative factors.

Bacteria feed on the simplest microorganisms, many of which are fish parasites. Thus, the fish’s resistance to pathogenic flora and fauna fails and it begins to get sick and die. In this situation, it is impossible to underestimate the benefits of UV water sterilization. If you choose and install this device correctly, you will prevent one of the most terrible factors affecting the organisms of your fish – the uncontrolled reproduction of pathogens in the water.

Ultraviolet rays (UV) can cause fatal damage to the cell membranes of bacteria and viruses, suppress their activity and destroy DNA and RNA. For most microorganisms, including pathogenic ones, such troubles become fatal and irreversible, even with a relatively small dose of radiation. Ultraviolet as a high-precision weapon affects living cells without affecting the chemical composition of the environment. The latter property distinguishes this device from all chemical methods of disinfection.

The UV sterilizer works in harmony with other existing filters. Treatment of water with ultraviolet rays allows it to be disinfected, destroying various undesirable microorganisms that develop in large numbers when contained in a closed aquarium system. Ultraviolet light creates a more favorable microclimate in the tank, reduces the pathogenic load on the inhabitants of the reservoir, provides water transparency, and prevents the mass development of microflora, which causes, in particular, water blooming.

The Best Aquarium UV Sterilizers Reviews

We’ve looked at a few UV sterilizer reviews and identified the best ones. Here are the most recommended, the best UV sterilizers both for freshwater aquariums and reef tanks.

Our the Best Picks for Saltwater Tanks

1. AA Aquarium Green Killing Machine Internal UV Sterilizer

This model is the perfect way to keep the aquarium and all its inhabitants clean without any chemicals.

This UV sterilizer creates disinfecting radiation and works together with a water pump. With this device, you can disinfect up to 50 gallons of aquarium water.

This device’s design allows water to pass quickly to maximize UV light, eliminating any dangerous organisms, such as mold, bacteria, yeast, etc. The product is extremely useful for cleaning algae and destroying microscopic organisms and destructive parasites present in the water.

This device works in aquarium water like internal filters and has plumbing for an easy install. Suction containers are also included for connecting a UV sterilizer [2].

Key Features:

  • There is no need for additional equipment.
  • Is fully submersible, making it versatile, easy to use, and useful.
  • Tested internal UV kit – be safe with your tank and fish!
  • Suction cups for easy mounting.



  • Sealed UV lamp.
  • Easy installation.
  • 3-year warranty.
  • Cheap plastic.

2. Coralife Turbo-Twist UV Sterilizer

This model of sterilizer has quartz protection that prevents water from getting inside. The Coralife Turbo-Twist UV Sterilizer is made of high-quality, durable materials. This is a certified model suitable for you if you are looking for a long-term installation for UV sterilization.

Unfortunately, this device is sold without a water pump (which ensures maximum performance); it must be purchased separately.

Key Features:

  • It can be used with freshwater and saltwater aquariums.
  • Up to 125, 250, 500 Gallons.
  • Very powerful lamp.



  • Inexpensive.
  • Can remove free-floating algae, parasites and bacteria.
  • Strong and durable.
  • Water pump not included.

3. SunSun JUP-01 9W UV Sterilizer Submersible Filter Pump

This high quality, UV sterilizer is well suited for tanks up to 75 gallons and can be used in aquariums or ponds with fresh or seawater, which makes this product a very versatile option.

This model does not require additional equipment or pumps. The device is already equipped with a water pump that transmits about 132 gallons of water for every hour of ultraviolet radiation. The lack of additional equipment can help you save money.

This device is also elementary to install. The model is equipped with a sucker for attachment to the inside of the aquarium. Besides, it can be installed both horizontally and vertically.

Key Features:

  • Included water pump.
  • Suitable for aquariums up to 75-gallons.
  • No additional hardware required.



  • Power – 9 watt UV light.
  • Perfect for small aquariums.
  • Can sterilize 210 gallons per hour.
  • Motor wears out after prolonged use.

4. Ecotech Marine Vortech MP60W QD Quiet Drive Wavemaker

In an aquarium, the availability of the necessary amount of clean water is crucial for the ecosystem’s health. For cleanliness in the aquarium, it is essential to install equipment such as a UV sterilizer. The technical characteristics of this model differ in quality and durability. VorTech pumps are designed by aquarists as the gold standard for providing flow in marine aquariums.

This device has more than 6 continuous operation modes, a feed mode and a night mode—less engine noise.

Key Features:

  • Can be used with saltwater aquariums.
  • 90% less motor noise.
  • Creates massive water movement.



  • Up to 40% more output.
  • Precise control of water movement.
  • Full 1-year manufacture warranty.
  • Quite expensive.

5. Aquatop Hang-On Back Aquarium UV Sterilizer Power Filter

Ensure smooth operation of the aquarium with the Aquatop aquarium filter with UV sterilizer. This device is equipped with a built-in UV sterilizer, which uses UV light to kill all algae and free-floating parasites, helping to keep the water crystal clear. This device also includes the function of ensuring a healthy gas exchange. This model is easy to install in most freshwater or marine aquariums from 15 to 40 gallons.

Key Features:

  • Great for marine or freshwater aquariums.
  • Removes algae blooms and free-floating parasites.
  • Suitable for aquarium frames up to 3/4 inch thick.



  • Includes surface skimmer and built-in UV sterilizer.
  • Helps aquarium inhabitants enjoy clean, clear water.
  • The unit is very easy to disassemble and clean.
  • Not suitable for large tanks.

Our the Best Picks for Freshwater Tank

1. Aquatop In-Line UV Aquarium Sterilizer

Experienced and novice aquarists know that maintaining a clean aquarium is a crucial factor contributing to the long life of fish and underwater plants. AQUATOP’s In-Line UV sterilizer disinfects an aquarium or other body of water.

Simply connect this device to the filter tube of the canister. When water passes through ILUV, it is exposed to UV radiation, and all bacteria and dangerous organisms die. The device works together with the existing filter, helping to destroy bacteria and keep your water crystal clear! It can also be integrated into most filtration lines [3].

Key Features:

  • Includes 3 different sized barbed fittings.
  • Can also be attached to most standard water pumps and powerheads.
  • Helps maintain the perfect health of the aquarium’s inhabitants.



  • Need the 10 watt UV bulb.
  • Easy install.
  • Easy to connect.
  • Some owners had a problem with a light bulb that stopped working after 3 months.

2. Jebao Easy Clean Bio-Pressure CF-10 UV Sterilizer Pond Filter

Keep your pond or aquarium clean and healthy with the Jebao Pressed Pond Bio biofilter with UV sterilizer. This device has a double filtration system along with an ultraviolet filter for maximum transparency of water in reservoirs with plants or fish.

This model works in three ways: a mechanical filter with foam pads removes debris; bio-balls promote the formation of beneficial bacteria that turn harmful ammonia and nitrites into healthy nitrates; a UV filter protects the water from algae. The device can purify up to 1000 gallons of water. Additionally, it has a convenient backwash function and a cleaning indicator, so you can easily keep it clean.

Key Features:

  • Includes foam filter pads, bio-balls and UV sterilizer.
  • Sterilizer promotes maximum water clarity.
  • Double filtration system.



  • Includes backwash feature.
  • Maximum filtering.
  • Supports a healthy aquarium environment.
  • Does not come with hose attachments.

3. TetraPond Green Free UV Pond Water Clarifier

The Pond GreenFree UV sterilizer is capable of producing significant algal blooms over a long period. The Tetra Pond Green Free UV illuminator is durable, easy to clean, and quick to install. The device is sold with a high-performance lamp that will last up to 11 months and a transparent quartz glass tube. The viewing window makes it easy to ensure that the UV lamp is working. It includes adapters for machines with an internal diameter of 3/4 inch, 1 inch and 1 1/4 inch, and a 15-foot power cord—UL in the list.

Key Features:

  • 3-year limited warranty.
  • Controls algae blooms.
  • UV lamp has a working life of up to 11 months.



  • 4 available sizes.
  • High-efficiency UV bulb.
  • UV clarifying light.
  • It may be difficult to find compatible tubes.

4. Lifegard Aquatics QL UV Water Sterilizer

The QL-15 watt UV sterilizer, when properly installed and used, is the most effective and efficient method of controlling a healthy environment in your pond or aquarium. This choice will help remove algae and stop unpleasant odors. It is effortless to connect and install. This easy-to-install, built-in aquarium UV sterilizer is very easy to connect and will work together with your filter to keep your aquarium clean.

Key Features:

  • Provides maximum UV transmission.
  • A unique spiral gives more efficient use of UV radiation.
  • Starts working instantly.



  • It can be rotated 360.
  • Easy installation.
  • Understandable instructions.
  • Short life span.

5. Lifegard Aquatics QL-25 UV Water Sterilizer

Most people don’t like the fact when algae make it unsanitary. The Aqua Ultraviolet Advantage can be ideal for you, as the device does not take up much space, which makes it suitable for small areas. Also, it is light, which means that it will not harm the tank or water element. It works well in various small water bodies, including aquariums and ponds.

Key Features:

  • It is very easy to connect and install.
  • The material provides the best UV transmission.
  • Ward off the emergence of cloudy and green tank water.



  • Easy installation.
  • Gasket seals quartz sleeve to cap.
  • Can help keep the tank pristinely clear.
  • Short life span.

Buying Guide

uv sterilizer for freshwater aquariumImage by @zoosnow from Pixabay

When choosing a UV sterilizer for an aquarium, you need to pay attention to these 4 criteria:


The higher the power, the stronger the dosage, and the positive effect of such a device is higher.

Gap or thickness of the treated water layer

Water absorbs ultraviolet light very quickly. Theoretically, in the water of medium transparency, which includes aquarium water, full absorption of ultraviolet rays occurs in a layer 0.1 inches thick. We can assume that this layer uses 100% of the lamp radiation, but the quality of processing is relatively low since only a small layer of the stream closest to the lamp receives a sufficient dose of radiation.

Accordingly, with a large working gap between the two flasks of the device, it is necessary to run it through the UV sterilizer repeatedly for the full treatment of water. Reducing the working gap significantly increases the efficiency of water treatment.


An essential criterion is when water is in the irradiation zone when passing through the sterilizer. That is, the longer the UV lamp, along which water flows, is in the irradiated area, the more the efficiency of water treatment increases.


There are two types of aquarium sterilizer: built-in and stand-alone. The first option implies the presence of a sterilizer in the aquarium filter. In the second case, the sterilizer is separate equipment that requires an aquarium pump for its operation – it actually pumps water into the sterilizer. The pump is selected based on the permissible performance of the sterilizer [4].

READ MORE: Aquarium Temperatures

Disadvantages of UV Sterilizers

A sterilizer is not medicine, but prevention

You can’t use it as a treatment. The UV sterilizer is disabled when using medications, in particular, aniline dyes (malachite green, methylene blue). Antibiotics and many organic dyes in it decompose, cease to have a therapeutic effect and the products of their decomposition can poison the fish.

It is better not to use UV sterilization when adding fertilizers to the water for aquarium plants.

UV treatment of metal salts-trace elements that are a necessary part of fertilizers, can transform them into a form that is toxic to fish.

Security regulations. In addition to the usual safety rules for working with electricity, the following rules must be observed:

  • Do not look at the lamp that emits UV radiation – with short-term exposure, you can get a corneal burn (and even go blind) and get severe skin burns. Ordinary sunglasses DO not protect against such radiation.
  • Turn off the UV sterilizer when using anti – and probiotics, as well as some other medications. Antibiotics and many organic dyes in it decompose, cease to have a therapeutic effect, and the products of their decomposition can poison the fish.
  • It is better not to use UV sterilization when adding fertilizers to the water for aquarium plants. UV treatment of metal salts-trace elements that are a necessary part of fertilizers can translate them into a form that is toxic to fish.
  • Do not use lamps that generate ozone unnecessarily. Uncontrolled ozone in the aquarium will lead to the death of fish (burns the gills). Also, ozone, in large quantities, is harmful to humans.
  • If the lamp is submerged in water, use a ground connection and a protective device that turns off the power when current leaks to the ground. This protective device is recommended for use in any electrical equipment that is used in the aquarium.

READ MORE: What Saltwater Aquarium Filter System Do You Need?

best uv sterilizers for aquarium


What is a UV sterilizer?

UV sterilizer for aquariums refers to a filter unit that uses an ultraviolet light bulb. This device allows you to get rid of parasites, bacteria, algae and viruses. Microscopic organisms are destroyed by an ultraviolet lamp by changing the structure of their cells. Irradiation does not significantly affect the fish. These devices are safe for use in home aquariums, swimming pools and liquid production plants.

What does a UV sterilizer do in a marine tank?

Water flows from the aquarium through a pump/filter to the sterilizer, through a unique tunnel. In the tunnel, the water is irradiated with ultraviolet light and goes into the aquarium. During irradiation with ultraviolet light, microorganisms in the water are killed.

What does a UV sterilizer do in a fish tank?

A UV sterilizer is used to fight infections by stopping the spread of microorganisms that harm fish/corals/invertebrates. If used correctly, free-floating microorganisms will be destroyed by ultraviolet radiation.

What size UV sterilizer do I need?

The unofficial rule of thumb in determining the wattage is 10 watts per 75 gallons water volume for saltwater application and 10 watts for every 150 gallons for freshwater closed systems. In pond application, this is significantly increased to 10 watts per 1000 gallons due to the sun’s natural capability of producing UV rays.

How to install UV sterilizer aquarium?

Install the UV sterilizer housing following the manufacturer’s instructions. Remember that you will have to change the light bulb and clean the device in the future, so put the sterilizer in an easily accessible place. Be careful, because the sterilizer contains a fragile sleeve[5].

How to use UV sterilizer aquarium?

A UV sterilizer is a device used in a tank or pond to remove bacteria, algae, and other nuisances, like Ich or other parasites. It’s an excellent supplement to your aquarium and prevents the death of fish.

Article Sources:

  1. Ultraviolet – Wikipedia. 28 Oct. 2020,
  2. “GKM | AA Aquarium.” AA Aquarium,
  3. HEPACART. What to Look for When Comparing UV Sterilization Devices.
  4. Ultraviolet Germicidal Irradiation – Wikipedia. 14 Oct. 2020,
  5. UV Water Sterilizers – Pure Aqua, Inc.

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