Last Updated on April 24, 2023 by Coral Realm

All aquarium buffs, no matter professional or amateur, understand the importance of a quality filter system to the health of both fish and plant life. 

Both freshwater and saltwater aquariums need the water to be properly treated and maintained, otherwise they can have harmful bacterial growth and the water can become cloudy and ugly. 

A regular internal filter uses mechanical cleaning methods and activated charcoal, which are very useful and work well, but can’t remove all algae and dangerous substances. Using an aquarium vacuum cleaner will help get rid of the large physical detritus and debris, but you still need to get rid of bacteria and viruses.

The best aquarium UV sterilizer is a great purchase for your tank, as it works in tandem with your filter to provide amazing water conditions for your fish. 


Top 8 Best Aquarium UV Sterilizer Reviews

Top 8 Best Aquarium UV Sterilizers

The following table lists out the top 8 best aquarium UV sterilizers on the market today t make it easier for you to see what different models are out there and where to purchase them. Keep reading on for the individual reviews and a complete guide on the benefits, how to choose the best UV sterilizer for you aquarium and how to install it properly.

What Actually is an Aquarium UV Sterilizer? 

A UV sterilizer is basically an additional element to your filter. It has a strong UV light bulb which destroys microscopic bacteria and algae that are floating in the water. 

UV light is a very effective tool for sterilizing; it has uses in many facets of life not only in aquariums. Swimming pools often have these devices, as do outside ponds to control algal growth. 

Bacteria, viruses, and parasites are all killed with a UV sterilizer, which includes all algae and wanted organisms in your tank.

Unwanted algal growth is the bane of any aquarist’s life, no matter professional or amateur. It can cause sickness in your fish and makes your water cloudy and ugly. An aquarium UV sterilizer kills any unwanted organisms and helps maintain the health of your aquarium. 

What Are the Benefits Of Having An Aquarium UV Sterilizer?

There is one major reason why you would want to install an aquarium UV sterilizer; they kill bacteria and viruses and keep your aquarium healthy. 

Aquarium UV Sterilizer

If you get a bacterial bloom or a build up of viruses they can be very difficult to get rid through normal cleaning and water changes. Bacterial blooms can make the water a very ugly cloudy color. An aquarium UV sterilizer, as you may have guessed, emits UV light which kills microscopic organisms by disrupting their DNA. 

UV sterilizers aren’t just useful in aquariums; you can use them in ponds like koi lakes too. It will help to control and manage the abundance of drifting algae which can be unsightly and harmful. 

As the rays kill bacteria, viruses, and parasites, they can be very useful in preventing and treating infections of your fish. If it is very difficult for whatever reason to catch fish to isolate them, for instance if you have lots of corals in the tank, a UV sterilizer will make life a lot easier. They will reduce the numbers of harmful microorganisms and with other treatment options will help to cure it. Aquarium filters won’t remove bacteria or viruses, so having something that will is very useful indeed!

However be careful when using a UV sterilizer as UV light can change chemicals into something else. For instance chelated copper is a common treatment compound, but UV light transforms it into ionic copper which can be very dangerous for your aquarium.

Flow rate and UV intensity can be changed on a number of models which allows for more or less thorough decontaminating. This can be useful as a slower rate helps in general maintenance and a faster rate can help if signs of infection appear in your fish.

If you have just set up a planted freshwater aquarium it isn’t advised to use a UV sterilizer as you need good useful bacteria in the tank to connect to the biomedia and gravel. A UV sterilizer doesn’t differentiate between the bacteria it kills, it will kill all indiscriminately. So wait till your tank is all set up before installing the UV sterilizer.

How Should You Decide On An Aquarium UV sterilizer?

There are many different models of UV sterilizer which cater for a huge range of flow rates and aquarium sizes. They also come in many different shapes and sizes and so while one may fit perfectly in your aquarium another might not. There are three main types you can get; tray, quartz lined tube, also called dry bulb, and non-quartz lined tube, also called wet bulb.

The dimensions of your aquarium and the UV sterilizer are quite important. Different styles of sterilizer will be better suited to different aquariums. There are inline models which can be submerged and linked to your filtration system. There are also the hang on models, which are easy set up as they just hang on the back of your aquarium.

Top 8 Best Aquarium UV Sterilizer Reviews

Best Aquarium UV Sterilizer Reviews

1. SunSun Aquarium UV Sterilizer and Submersible Filter Pump

SunSun JUP-01 9W UV Sterilizer Submersible Filter Pump
  • Suitable for tanks up to 75-gallons
  • Dimension: 12" L X 3.3" W X 3.75" H
  • Flow rate: 210 gallon per hour
  • 9 Watt UV light

This aquarium UV sterilizer by SunSun is a very versatile model that will work well with any kind of aquarium you may have, be it freshwater, saltwater, or an outdoor pool. This is perfect as you know that this model will work well in your tank.

It is very easy and simple to mount and get ready to go. Suction cups enable you to place it on the side of your tank, and it can be mounted both vertically and horizontally. 

It is suitable for tanks up to 75 gallons, and has a flow rate 210 gallons per hour. What is very useful about this UV sterilizer by SunSun is that it incorporates a water pump, so it comes ready to install and use. This is super useful as you won’t have to buy any other additional products to use this one, therefore helping you save money.

It has a built in mechanical pre filter sponge, which prevents the mechanism from becoming clogged. It is recommended to change the UV bulb every year to maintain maximum effectiveness. 

Whilst this is a great model, there are some drawbacks that you can see through looking at reviews. There seems to be some issues with how well it is manufactured, with some users mentioning that it has malfunctioned and the plastic has melted, or leaked into the water. It does seem a little too big for the size of tank it is meant to facilitate, and the flow rate is very high, so isn’t really suitable for fish that like calm water. It is very cheap, so you get what you pay for it seems. The vast majority love this product however.

2. Aqua Ultraviolet UV Sterilizer 

Aqua UV 25 Watt 2 inch UV Sterilizer
  • Fresh Water Sterilizer: 500-1,200 gallons; Flowrate - 1,200 gph for 30,000 µw/cm2SUP>
  • Fresh Water Clarifier: up to 4,000 gallons; ideal for water gardens
  • Salt Water Sterilizer: up to 150 gallons; Flowrate - 400gph for 90,000 µw/cm2SUP>
  • Dimensions: 26.25" X 4" X 2.5"
  • Inlet: 2" slip, Outlet: 2" slip

Aqua Ultraviolet is a brand known for excellent, no nonsense products. These products work very well and have brilliant functionality. The 25W model is the mid range sized model, so is most likely to fit your aquarium, though there are also 8, 15, and 40W models available too.

This aquarium UV sterilizer can be used both outside and inside, so can be used on ponds as well as indoor aquariums. It can be used on both saltwater and freshwater. The design allows for freshwater tanks of up to 1200 gallons and saltwater tanks of up to 150 gallons.

The UV sterilizer is shipped with the lamp quartz sleeve and the transformer pre-installed, so you don’t need to do any further work. It is very small, which makes it very easy to find a home for it in your aquarium. It is 20 inches long, 3.75 inches wide and 6 inches high. The bulbs will last for 14 months before needing to be replaced.

3. AA Aquarium Green Killing Machine UV Sterilizer

AA Aquarium is another company which is recognized as a leading brand in manufacturing quality aquarium products. The AA Aquarium Green Killing Machine UV Sterilizer is an aquarium powerhead and UV sterilizer combo, so you don’t need to buy a separate pump. It has a sponge and filtration pump included.

This UV sterilizer is suitable for both freshwater and saltwater aquariums, and is fairly small and compact so can be hidden from view behind plant life and other things in your tank so it isn’t an eyesore. 

There are suction cups attached to the back for ease of placement. An LED light signals the need to replace the bulb. UV lights are known to wear away plastic, so can degrade the plastic housings. When you replace the bulb in this model you replace the housing too, so the safety of your aquarium is secure.

The pump has a flow rate of 50 gph but to maximize sterilizing time the flow is reduced via a zigzag flow within the bulb. This reduced flow improves UV efficiency, as there is more contact time between the water and the UV bulb.

Be a little wary about buying this model however, as though most of the reviews are very good, some people complain of noises being made soon after purchase, and also with the bulb months before it should be due to be changed.

4. Jebao Aquarium Koi Fish Pond UV Light Sterilizer

This aquarium UV sterilizer by Jebao is non-submersible, so needs to be connected outside your aquarium or pond. Debris in the water will block the UV light and will hamper the sterilization process. Therefore you will get best results if you attach this model after the filter has taken out all the dirt and debris. The UV light disrupts the DNA or RNA of microorganisms which subsequently kills them.

If you must install this sterilizer before the filter for whatever reason, then to protect the quartz sleeve from damage from debris you should install adequate pre-filtration.

If the sterilizer is installed before the filter it should take around 7-10 days for green water to clear, whilst if it is installed after the filter it should take around 3-5 days. If the effectiveness of the sterilizer starts to wane, then the quartz sleeve surrounding the UV bulb may need cleaning, as a film can build up which blocks the UV rays.

The power cord is 22 foot long, so will reach most ponds and aquariums even if there aren’t power sockets right next to it. It can be installed both horizontally and vertically depending on what is best for you, but you shouldn’t over-tighten the connections otherwise you risk leakage.

5. AA Aquarium Green Killing Machine Internal UV Sterilizer 

The second model by AA Aquarium on this list, which shows how highly rated the company is. This aquarium UV sterilizer model uses wavelengths of 254nm to provide your tank with chemical free cleaning. It is suitable for tanks of up to 50 gallons.

The design of the UV sterilizer means the water flows in a zigzag pattern past the UV bulb, so therefore maximizing the water to exposure to the UV rays. Thus will heighten the ability of the UV light to kill bacteria, viruses, and other pathogens. 

Installation is extremely simple as the UV sterilizer is fully pre assembled right out of the box. This model is submersible, and comes with suction cups so you can attach it to the side of your aquarium. You have have it either vertical or horizontal or so can hide it behind ornaments to prevent it from being an eyesore.

A power head is attached which draws in water, so you don’t need to attach it to your filter. You only need to plug it into a mains socket and you will be good to go. 

This aquarium UV sterilizer, like the other AA Aquarium model, has an LED bulb which will signal when you need to change the UV bulb.

The reviews are very positive, and for the price you can’t really beat it. However some reviews mention that the plastic casing has a cheap feel to it.  

6. Coralife Turbo-Twist UV Sterilizer

Coralife Aquarium Fish Tank Marine Salt Water Turbo-Twist UV Sterilizer 6X, For up to 250 Gallons
  • Removes free floating algae, parasites and harmful micro organisms from aquarium water
  • Features a unique twist flow design increases water’s exposure to ultraviolet light improving the treatment of unwanted algae and microorganisms
  • For fresh or saltwater applications
  • Easy setup and installation, includes mounting brackets for hang-on or inline applications
  • Indicator light lets you know when the sterilizer is operating

Coralife is another well known brand in aquarist circles. This aquarium UV sterilizer model can be used on both freshwater and saltwater aquariums of up to 250 gallons. This is far a greater volume than many other models on this list, so if you have a larger aquarium do look hard at this model. There are also other models of this sterilizer by Coralife which will suit larger or smaller tanks. 

Mounting brackets are included which allows for side mounted and in-line applications. For side mounted, simply hang this UV sterilizer on to the side of your aquarium with an attached pump. For in line applications just install it after your filter and it will work wonders.

It features a unique twist flow design which enables water to flow more evenly through the sterilizer and past the UV bulb. The bulbs are constructed from quartz glass which allows for maximal output of UV rays. Indicator lights show when the sterilizer is working. An intense 18 watt bulb and the spiral design greatly increase dwell time which improves the units capacity to kill and treat bacteria, viruses, algae and other pathogens in the water.

This UV sterilizer by Coralife has a very powerful bulb, is very affordable for the features it offers, and is a great option. The only negative is that it requires a pump if you wish to connect it side mounted, which is not included. These can be picked up pretty cheaply and easily though.

7. AquaUltraviolet Advantage Aquarium UV Sterilizer

AquaUltraviolet Advantage 2000+ Inline 3/4" Barb - 15 Watt Aquarium UV Sterilizer
  • The Advantage Series is ideal for small ponds, aquariums and water features
  • A UV Sterilizer is a proven method to eradicate bacteria, viruses and protozoa
  • Made in United States

The AquaUltraviolet Advantage Aquarium UV Sterilizer is ideal for use in small aquariums, ponds, or water features of up to 75 gallons.  You can use it in both freshwater and saltwater tanks.

This model will clear your tank in a maximum of 5 days, often sooner. Ensure that you install it according to the manufacturer’s guidelines.

This UV sterilizer is very slim and is quite small. It won’t take up much room in the tank, which makes it perfect for smaller aquariums. Useful as it should only be used in tanks of 75 gallons or less!

A timer is included which is extremely useful. There is an issue with seals it seems, so make sure you check them thoroughly so you don’t sprout any leaks or drips. Overall if you have a smaller tank then this model will be perfect for you.

8. Coodia Aquarium Internal UV Sterilizer

COODIA Internal Green Water Killer Aquarium Filter Tank U-V Pump
  • Turns green water to clear in 3 to 7 days.
  • Suitable for Saltwater and Freshwater.
  • Clean up to 75 gallons tank
  • Built in 5 watt water pump

This Aquarium UV Sterilizer by Coodia is suitable for aquariums and ponds of up to 150 gallons. It is suitable for both freshwater and saltwater tanks. The ceramic rotator is anti-corrosive, which enables it to be used for saltwater.

The is a built in 5 watt water pump, so you don’t need to purchase anything else to install this UV sterilizer. There are four strong suction cups on the back of the unit which allows you to stick it to the side of your aquarium.

The 5 Watt UV light bulb is included, which effectively kills any bacteria, viruses, and protozoa in the water. If you have a cloudy tank it will clear it up in no time.

The water outlet is adjustable so you can choose the direction the water flows once it leaves the UV sterilizer. This is a very useful function as in smaller tanks especially as you may have certain plants which do not like to be in full water flow. There is also an air bubbler which will generate bubbles in your aquarium and help to oxygenate the water.

How Does a UV Sterilizer Work?

An aquarium UV sterilizer works in tandem with your filter to provide unparalleled clean water. While the filter will take out dirt and debris any microscopic organisms and pathogens in the water which can cause harm to your fish will remain. This is where the UV sterilizer comes in.

These microscopic organisms are killed by the UV sterilizer by being exposed to the UV rays as they pass through the unit. The UV light damages and destroys the DNA in these microscopic cells, effectively killing them. The high levels of radiation in the unit also kill these pathogens. 

The units are always dark in color as this blocks the UV radiation from entering the tank and damaging the fish and plant life.

How Do You Install a UV sterilizer?

It is fairly simple and easy to set up and install a UV sterilizer in your aquarium or pond. Always follow the manufacturers guidelines, and make sure that you put the sterilizer in an appropriate place. 

Concentrate on how you set it up and get it going, as it will make it a lot easier when you need to clean it or change the bulb if you remember what goes where and how to install it again! 

If you can, always install your aquarium UV sterilizer after the filtration system. The filter will remove dirt and debris and will make your UV sterilizer work more efficiently. Having dirt and debris suspended I’m the water will blow the UV light rays and prevent it from working at full capacity.

Conclusion and Our Recommendation 

To conclude, an aquarium UV sterilizer is a great way of getting and maintaining a very healthy tank. They kill bacteria and other microorganisms in the water which can cause cloudy water or harm your fish. 

Take the time to research and purchase the best sterilizer model for your tank, as there are many different styles and size capacities you can get. Make sure you abide by the manufacturers guidelines and install it correctly so you don’t have any issues, and clean it regularly to maintain the effectiveness of the UV sterilizer. Try to change the bulb at least once a year, or more often if instructed. 

Our recommendation for the best aquarium UV sterilizer is the Coralife Turbo-Twist UV Sterilizer. It has a high wattage UV bulb and has a unique twist flow design which allows for maximal contact between the water and the bulb.

Coralife Turbo-Twist UV Sterilizer

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