Best Aquarium Sterilizers in 2021

Best Aquarium UV Sterilizer Guides
By Garrison Hickles Updated

Fishkeeping is a highly dedicated hobby since you are dealing with actual living beings here.  To ensure their safety, installing an aquarium UV sterilizer is essential. However, buying an aquarium UV sterilizer can seem to be a complicated process.

This can be solved when you have detailed knowledge of its functionalities and the pros and cons of the various UV sterilizers available in the market. This is exactly what we are going to do today as we present before you a list of the best aquarium UV sterilizers. But before we do so, you need to understand what they are and how they can help your aquatic pets and plants.

What is an Aquarium UV Sterilizer?

An aquarium UV sterilizer is a water filtration gadget that kills harmful microorganisms (virus, bacteria, and parasites) in the tank water with the help of UV (Ultraviolet) light bulbs. It does so by altering the cell structure or DNA of these microorganisms. This, in turn, means that you have to change your tank water less frequently.

When the water goes through the in-line cleaning unit, the UV bulbs eliminate the various types of microorganisms present in it.

In addition, it also takes care of one of the most frustrating problems that all aquarists face to varying degrees- algae bloom. Yes, you heard that right! With a UV sterilizer in your aquarium, you don’t have to worry about algae infestation ever. It also helps in keeping the tank water clean, thereby making sure it never gets clouded and cause discomfort to the living beings inside.

Let’s move on to review the best aquarium UV sterilizers you can get today.

5 Best Aquarium UV Sterilizers – A Review

After conducting extensive market research and getting experts advice on the concerned subject, we have finalised our list to the following five aquarium UV sterilizers. Please note that this is not a ranking.  The following products have been listed in random order.

Coralife Turbo-Twist UV Sterilizer

Starting our list of the best aquarium UV sterilizers is the Coralife Turbo-Twist UV Sterilizer. Having the tremendous ability to deal with tanks as large as the ones that have the capacity to hold 500 gallons of water, this can be used both in freshwater and saltwater aquariums.  

Its 18-watt UV light is highly efficient in eradicating bacteria, viruses, parasites and algae from your tank. It is also extremely durable which is evident from its quartz glass sleeve which secures the light and prevents water from coming into its contact. Moreover, it is extremely easy to install and lasts long, thereby proving to be a worthy investment on your part.

It has sections for in-line applications and you can also mount it by hanging it on the side of your aquarium.  To derive the maximum performance from this sterilizer, you need to buy a pump (with a flow rate of 300-900 gallons per hour) separately and attach it to its rear end.

It also features an indicator light that tells you whether the unit is operating or not.


  • Suitable for both freshwater and saltwater tanks
  • Durable
  • Affordable
  • Can be installed by hanging as well as through in-line
  • Efficient bulb
  • Strong quartz glass sleeve
  • A great buy for large tanks


  • Needs an additional pump for reaching its full potential
  • The bulb doesn’t tightly fit in the socket

AA Aquarium Green Killing Machine Internal UV Sterilizer

The AA Aquarium Green Killing Machine Internal UV Sterilizer is one of the most highly-efficient UV sterilizers that specialize in eradicating microorganisms that are responsible for algae bloom in an aquarium.  

It does a great job at making sure the water of your tank remains clean which helps both your aquatic pets to swim freely without suffocation and also helps you in getting a clear transparent vision of the aquarium. Operating with the help of a water pump, it provides a disinfecting radiation with a wavelength of 254 nm.

This 9-watt UV sterilizer is suited for aquarium up to 50 gallons with a flow rate of up to 60 gallons per hour.  In order to increase the dwelling time without decreasing the flow rate, the motion of flow takes place in a zig-zag fashion in the UV chamber.

Another interesting aspect about this product is that it comes with a sealed bulb, which means that you won’t need to wear gloves while changing the bulb since you wouldn’t directly touch the bulb itself. There is also an LED on the control box that will notify you when it is time to change the bulb.

It is also very is easy to install this product and since it comes with suction containers, you don’t have to worry too much about its setting up process.  It doesn’t have to be connected in-line in your aquarium system. Instead, you have to hang it inside your tank. The sterilizer in itself comes pre-assembled. It comes with a 3-year warranty, which is a bonus.

However, it is a bit on the expensive end of the spectrum and we believe the quality of the plastic on its body could have been better.


  • Easy installation
  • 3-year warranty
  • Powerhead included
  • Comes with suction cups


  • Expensive
  • Quality of plastic could have been better

AquaUltraviolet Advantage 15-Watt Aquarium UV Sterilizer

Next up on our list of the best aquarium UV sterilizers is the AquaUltraviolet Advantage 15-Watt Aquarium UV Sterilizer. Have you ever stressed yourself out over the way algae discolour the tank water and no matter how frequently you replace the water, you are back to square one? Well, in that case, you need to buy this product because it does an excellent job of clearing the tank water and making it transparent.

Despite a strong built, it is extremely lightweight and doesn’t take too much space in your aquarium.  It can serve well in tanks of up to 75 gallons in size with a flow rate of up to 240 gallons per hour. You can even use it for small ponds, although it would take a couple of days before showing its result in a pond.

Since the exterior tube is made from heavy-duty PVC plastic, you can rest assured that it will be durable.  The company also has a great customer support system. However, finding the hose size for the pump filter can be tiresome.  


  • Long-lasting
  • Can be functional even in a small pond
  • Excellent customer care support
  • Easy installation


  • Finding the right hose size for the pump filter can be difficult
  • The seal is not strong enough and needs to be secured by double-checking

SunSun 13W UV Sterilizer Adjustable Pump Filter

Suitable for freshwater and saltwater tanks as well as small ponds, the SunSun 13W UV Sterilizer Adjustable Pump Filter can support up to 75 gallons tank size.

A great aspect of this UV sterilizer is that it doesn’t need any additional pump or hardware. It already comes with a water pump with a flow rate of 132 gallons per hour. You can either mount it horizontally or vertically based on your preference. It uses suction cups to stay connected to the interior walls of the aquarium.

In addition, you will also find a filter sponge with it which wipes off the debris from it before the water moves to the UV light section. Since the chamber has a large length and diameter, the sterilization is highly effective. However, this large size is also responsible for producing a lot of suction. This means that the water will be slightly turbulent and it may not be suitable for the fish species that are accustomed to living in calm waters.

Among the downside, the suctions cups don’t stick perfectly on unbalanced edges, although this problem only rises when you are using it in ponds. Also, its body is not the strongest of the bunch and is a bit delicate. So, be careful while handling it.


  • Built-in water pump
  • No extra hardware required
  • Easy to mount
  • Can be mounted both horizontally and vertically
  • Suitable for both freshwater and saltwater tanks as well as small ponds
  • Features a 13-watt UV light


  • Built is not strong enough
  • Not ideal for fish that prefer calm waters
  • Suction cups don’t stick properly on rough or unbalanced edges of ponds

Brother123shop 9W UV Sterilizer

Next on our list of the best aquarium UV sterilizers is the Brother123shop 9W UV Sterilizer that has the ability to clear the green water of tank within a week.

In sharp contrast to the chemical water treatments, this UV sterilizer does its job of killing microorganisms and cleaning the tank without harming your aquatic pets. It is suitable for small to medium-sized tanks. So, a 75-gallon tank with a maximum flow rate of 211 gallons per hours is its upper limit. Besides, it is very easy to clean and maintain.

Like most sterilizers, it will also kill off beneficial bacteria. So, if you want to restore them, we suggest you make preparations with some other medium so that beneficial bacteria can still grow. Also, the instructions about the setup of this product are not in English which might cause some difficulties. Other than that, this is a worthy buy.


  • Features an 8-watt pump power
  • Comes with a 9-watt UVC light
  • Equipped with a 9-watt UV power (G23 base)
  • Doesn’t harm your aquatic pets with any chemicals


  • Setting up can be difficult since instructions are not in English


We are almost at the end of it. But before we conclude our buying guide for aquarium UV sterilizers, there are a couple of things that you must know.

Usually, the bulbs of your aquarium UV sterilizers need to be replaced every six months. Whenever you replace the bulb, try and not look at it directly when the switch is on since it can severely damage your vision. In addition, inspect the quartz sleeve on a monthly basis. You can clean it by removing it and rubbing alcohol on it before placing it again. Some expensive sterilizers come with their very own wiper mechanism units that can be set up for general sailing maintenance.

However, one concern with UV sterilizers is that it doesn’t discriminate between beneficial and harmful microorganisms and kills them both. A new tank requires beneficial bacteria for setting up the environment for your aquatic pets and plants. This is why it is suggested to avoid running the VU sterilizer when you are cycling your tank for the first time. This will allow the beneficial bacteria to settle down at the bottom of tanks in gravels and corals, thereby, protecting themselves from the UV rays of your sterilizer.

All in all, you must provide a UV sterilizer to your aquatic pets and plants so that they can live a safe and healthy life. They need your protection and you must do everything in your power to give them a safe home.  Whenever you make your purchase, keep our buying guide in mind so that you get your money’s worth.

Similar Fishkeeping Articles

As an aquarist, we are certain that the following articles would be useful for you:

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