10 Best UV Sterilizer for Aquariums

I am sure:

You want your aquarium to stay clean and bright all year round.

and If you have a lot of fish, this can be a problem.

It can also be hard to keep it clean in an area that has higher humidity or temperature fluctuations.

And this is where a UV sterilizer for aquariums can help.

It attaches to the side of your aquarium and helps to keep it free of algae and bacteria.

Check out the list of the 10 best UV sterlizers for Aquarium below:

Contents show

Best UV Sterilizer for Aquariums

AA Aquarium Green Killing Machine Internal UV Sterilizer


This UV sterilizer helps to remove bacteria, cloudiness, and impurities from your aquarium’s water. This leaves it clear and healthy for your fish. It’s designed to handle aquariums up to 53 gallons. The LED bulb will signal when you have to replace it as well.


  • It comes with a step by step installation guide that is very user-friendly.
  • The UV sterilizer works on a variety of aquariums up to 53 gallons.
  • It cycles through the water at a rate of 200 liters per hour.


  • It may take up to a week to clear up your aquarium.
  • The unit may only work well for a few months before it slows down.
  • The cord connects to the top of the device at a weak point.

SUN 13W UV Sterilizer Adjustable Pump Filter


The sterilizer comes with an eight watt pump built in. It’s suitable for both freshwater and saltwater aquarium setups. This small sterilizer works for aquariums up to 150 gallons. You get a 13 watt UV light included with the unit as well. There is an adjustable water flow regulating nozzle attached for your convenience.


  • This unit can work in several different aquarium sizes up to 150 gallons.
  • It’s very slender and easy to attach to your aquarium.
  • You get an eight watt pump with a 13 watt UV light.


  • It might not be powerful enough to keep up with a 150 gallon aquarium.
  • The sterilizer may corrode quicker in a saltwater aquarium.
  • The inner tubing is made out of glass and prone to breaking.

Aqua UV 15 watt Advantage UV Sterilizer


This UV sterilizer works well for a variety of spaces including ponds, aquariums, and various water features. It is made in the United States following strict quality control guidelines. It works to remove bacteria and algae that can cause your tank to turn green or discolored.


  • This unit works very well in several different size aquariums and ponds.
  • It’s very compact and sleek so it fits into smaller aquariums easily.
  • The UV sterilizer is made in the United States following strict guidelines.


  • The transformer may burn out and stop working after a year or two.
  • It can be difficult to keep it upright and stable when it’s running.
  • The locking screw for the supply tubing tends to loosen by itself.

Coralife Turbo Twist UV Sterilizer


Coralife’s UV stabilizer is designed to remove any free floating bacteria, algae, or contaminants from your aquarium. The twist flow design allows for a higher amount of UV light. You get mounting brackets included that make it easy to install. It works in aquariums up to 125 gallons.


  • The unit comes with an indicator light to let you know when it’s time to switch the bulb.
  • You can use this UV stabilizer with freshwater and saltwater aquariums.
  • It works with a variety of different aquarium sizes up to 125 gallons.


  • The twist design can stick and be difficult to turn.
  • The plastic housing doesn’t stand up to saltwater corrosion well.
  • The inner walls are metal and prone to rusting.

COODIA Internal UV Sterilizer Filter Aquarium Tank UV Light



You’ll get up to 8,000 running hours on a single UV bulb. This UV stabilizer controls mold, algae, pathogens, bacteria, and yeast. This leaves you with a clear tank to keep your fish healthy. It has a protective casing that allows you to submerge it without damage.


  • You can get up to 8,000 hours of use out of a single UV bulb.
  • The device uses suction cups to attach to the tank for easy removal.
  • It can handle tanks up to 130 gallons without a problem.


  • The suction cups may not stick to the side of the tank.
  • The light indicator is hidden inside the compartment.
  • The air intake feature can be sluggish or stop working.

rOXIN 7W 11W Submersible UV Light Sterilizer


This UV light sterilizer is slightly larger at 13.4 inches long. It’s suitable for larger tanks up to 500 gallons. You get around 10,000 hours of light from a single bulb as well. It comes with a 30 day money back guarantee. You also get a lifetime support guarantee.


  • It works in larger aquariums and ponds up to 500 gallons.
  • You get up to 10,000 hours of use out of one UV light.
  • It works to clean the water in just three or four hours per day.


  • If you’re not careful with it, it could harm your fish.
  • This sterilizer isn’t recommended for smaller tanks because it’s too powerful.
  • The slightly larger design can be difficult to place securely.

SunSun JUP-01 9W UV Sterilizer


This UV sterilizer has a flow rate of 210 gallons per hour. It is suitable for aquariums 75 gallons and smaller. The nine watt UV light helps to clear your aquarium’s water up by getting rid of algae and bacteria. You can submerge this device in water without any issues.


  • This UV sterilizer is very easy to setup, use, and maintain.
  • It works great for smaller ponds or smaller aquariums.
  • You get thousands of hours of use out of a single bulb.


  • It might take up to a week to see noticeable differences in your water.
  • This unit can’t keep up with the demands of a larger aquarium.
  • It may get too hot and damage the plastic housing unit.

AquaTop In-Line UV Sterilizer


You’ll get three different sized barbed fittings with this sterilizer. These three different options allow you to secure it to the side of your tank quickly and easily. The 10 watt UV bulb works great in aquariums up to 450 gallons. It has a slightly larger design that comes with five foot connection cable.


  • You get three different fittings with each UV sterilizer you purchase.
  • This unit works great in larger aquariums up to 450 gallons.
  • The connection cable is longer and easy to adjust to the perfect length.


  • It is almost a foot long and too powerful for smaller aquariums.
  • The bulb is fragile and it prone to cracking or shattering.
  • There are a few spots that leak from the housing or outer casing.

Flexzion UV Sterilizer Light


This compact and durable UV sterilizer comes with an integrated on and off switch. It is outfitted with rubber seals to prevent leaking at the attachment points. The indicator light warns you when your UV light is going dim so you can replace it. It works on larger aquariums and ponds up to 550 gallons.


  • The device comes with a flow meter built in so you can monitor it.
  • It has a more compact and durable design than other choices.
  • You get an 18 watt UV bulb with an indicator light.


  • This device may only work well for a few months before it slows down.
  • You can’t submerse this UV sterilizer in the water.
  • It may trip your fuse box if you have several things plugged in at once.

Bivisen Submersible 10W UV Sterilizer Light



This unit comes with a 10 watt UV light that is designed to run for two or three hours a day. It works to remove any bacteria, algae, or germs from your aquarium’s water. This light attaches easily to the side of the tank with suction cups. It works well in aquariums up to 350 gallons.


  • You only have to run this sterilizer two or three hours per day.
  • It works to remove any bacteria, germs, or algae in your aquarium.
  • This device has a user-friendly design that attaches to the tank with suction cups.


  • It’s powerful enough to harm your fish if you run it constantly.
  • There is no indicator light to warn you that the light is dying.
  • This UV light can damage your eyes if you don’t pay attention when you install it.

What is a UV Sterilizer?

A UV sterilizer is a device that uses UV light to destroy algae, bacteria, and other free-floating microorganisms in your aquarium water. They run continuously or for a few hours a day depending on the model and strength of the UV light.

Important UV Sterilizer Factors

Aquarium Size

Your aquarium size is one of the biggest factors when it comes to buying your UV sterilizer. Some are too powerful for smaller aquariums and they’ll damage your fish. Other sterilizers are too small. They won’t be able to keep up with the demands of a larger aquarium.

Attachment Points

Do you want your UV sterilizer to attach to the side of the tank with suction cups? If not, do you have the space you need to hang part of your sterilizer over the side of the tank? Your attachment points will anchor your UV sterilizer to your tank. It’s important that they’re secure and durable.

Submersible or Non-Submersible

There are UV sterilizers that you can submerge into your aquarium’s water. They actually run better this way. However, many units are designed to run without being completely submerged. You have to find on that suits your aquarium’s needs, and that will run how you want it to without breaking.

Frequently Asked Questions

Does the UV light kill the good bacteria in the aquarium water?

Yes. The UV light will effectively kill all of the bacteria in the aquarium water. The UV light won’t kill the good bacteria that live in the filter.

Do you run the UV light all the time?

Some UV sterilizers are meant to be constantly run. Others are more powerful, and you only run them for a few hours a day. Check the manufacturer’s instructions to ensure you’re using it correctly.

Does the UV sterilizer work right away?

No. It can take up to a week before you notice any significant changes. Aquariums with more severe buildup will likely take longer to clear up.

Can you use a UV sterilizer with live plants in the aquarium?

Yes, you can use this tool with live plants. However, you may only want to run it for a few hours a day. This will limit the plant’s exposure to the light.

Can you use these sterilizers in saltwater aquariums?

You can use more of these UV sterilizers in saltwater and freshwater aquariums. If it doesn’t say so right on the box, you may want to check the manufacturer’s website or call into double check.

Does this help with algae that are growing on the sides of the tank?

It will help with algae growth on the sides of the tank to a point. However, the main focus is to get rid of anything floating in the water itself.

How does this sterilizer get rid of algae?

When the UV light hits the algae that are floating in the water, it makes it unable to reproduce and bloom. This effectively kills it off and prevents it from returning to your tank’s water.

Are there different size sterilizers for different aquariums?

Yes. Some UV sterilizers are more powerful than others. The more powerful ones work best in ponds and larger aquariums. Small sterilizers can keep up with smaller aquariums better without harming the fish.

Do they work with different filters?

You can use your new sterilizer with your existing filtration setup without a problem. They’re designed to be universal and fit a variety of filter types and brands.

Can you use the same sterilizer for ponds and indoor aquariums?

It depends on the size and brand. Some UV sterilizers are meant for indoor use only. Other ones do well in ponds or indoor aquariums. Again, be sure you check with the manufacturer before you use it.

Does a UV sterilizer replace the filter system?

No. You hook your sterilizer up to the aquarium or pond’s filtration system. This helps to eliminate free-floating algae and bacteria. Your filter system will catch and hold it to keep your water clear.

Do they all come with indicator lights?

Having an indicator light is nice because it tells you when the UV bulb is dying. However, not all UV sterilizers come with an indicator.

Do these sterilizers run quickly or slow?

A lot of the sterilizers are designed to run very slowly. They cycle through your aquarium’s water at a very slow pace. Larger sterilizers can cycle through quicker.

How do you attach them to your aquarium?

Most UV sterilizers come with suction cups that you simply stick to the side of your tank. Others feature a lip that hangs over the tank’s ledge and anchors the sterilizer to it.

Can you submerge all UV sterilizers?

No. Some UV sterilizers work very well when you submerge them completely. However, there are others that require it not to be submerged for it to work correctly.

Can these devices overheat the aquarium?

It depends on the size of the tank, the size of the sterilizer, and how long you let it run. Normally, this won’t cause your tank’s water to heat up because it only runs for a few hours a day or it runs slowly.

How often do you have to clean the sponge?

It depends on how dirty your aquarium is. You do want to clean it at least once a month. You can give it a quick rinse under water to clean it.

Can you place the devices horizontally and vertically?

As long as the UV sterilizer isn’t completely submerged, you won’t have a problem putting them horizontally or vertically.

Can you adjust the gallons per hour?

Yes. Most UV sterilizers have an adjustable gallon per hour switch or button. You simply turn it until you get the flow rate you want

When the bulb burns out, do you just replace it?

Unfortunately, when the bulb burns out, you’ll most likely need to replace the whole internal bulb and casing. They’re usually not too expensive or difficult to replace, however.



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