Best UV Sterilizer For Aquariums: Top 7 Reviews | Aquascape Addiction

Best UV Sterilizer For Aquariums: Top 7 Reviews

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We review our top 7 Best UV Sterilizer For Aquariums that we feel are worth a mention, each covered in detail with helpful information on how they can benefit your tank.

Best UV Sterilizer For Aquariums: Top 7 Reviews

Of course you want to do everything in your power to keep your fish happy and healthy. This means feeding them right, changing the water, and providing for a fun environment to live in. Doing all of this can be kind of hard, but it does not have to be, especially when you have the right tools. One of the most useful tools that helps to ensure clean water is a aquarium UV sterilizer.

The Best UV Sterilizer for Aquariums is one that can kill as many bacteria and microorganisms as possible, and that is exactly what we are going to help you find. This is our top pick.

Coralife Turbo Twist 18W 9.7/10
Aqua UV Hang On 15W 9.6/10
AquaTop In-Line 10W 9.4/10
Green Killing Machine 9W 9.4/10

How Does A Aquarium UV Sterilizer Work?

A aquarium UV sterilizer works by emitting UV rays just like the sun would. It is a small bulb that releases UV light which helps to kill off bacteria, viruses, algae blooms, and other harmful microorganisms that you don’t want in your fish tank.

UV light is harmful to small microorganisms, therefore killing them off, and keeping your fish tank water clean and clear.

Benefits Of Having A UV Sterilizer In Your Aquarium

The benefits of using a UV sterilizer are pretty clear, excuse the pun. A UV sterilizer is great for killing off a variety of bacteria, viruses, and other microorganisms that can cause water impurities.

Bacterial outbreaks, viruses that can affect your fish, cloudy water, and algae blooms will all be eliminated with the use of a single UV sterilizer. This means having to change the water less, plus it helps reduce the strain on your filter too.

What We Think Is the Best UV Sterilizer For Aquariums

If you are looking for a great UV sterilizer for your aquarium, this is in our opinion one of the better options;

Coralife Turbo-Twist Ultraviolet Sterilizer

This is a great large UV sterilizer to consider. (You can check the current price at Amazon here). One of the best parts about it is that it can handle huge aquariums of up to 500 gallons. Moreover, it can handle both fresh and salt water tanks, a very versatile feature indeed.

Moreover, this thing can be mounted by hanging it on the side of the aquarium, and it also has brackets for in line applications. This way, if you have a pump with a flow rate in between 300 and 900 gallons per hour, you can simply hook up the Coralife Turbo-Twist to the end of the filtration unit to keep your water clean and clear.

This sterlizier does a great job at killing algae and organisms thanks to the powerful 36 watt UV lamp. The lamp is covered with a quartz glass sleeve to keep water from getting in, thus greatly increasing its durability. This thing is durable, easy to install, and it does a heck of a job at cleaning your water.


  • Ideal for extremely large tanks.
  • Good for salt water and fresh water tanks.
  • Very powerful bulb.
  • Quartz casing for durability.
  • Hang on or in line use.


  • Requires a water pump which is not included.
  • Bulb fits loose in the socket.

See more info and pricing at Amazon

6 Other UV Sterilizer Worth Considering For Your Fish Tank

You may not be a big fan of the UV sterilizer that we chose as the number one pick, but there are always a few more that you can look at which might suit you a little better, here are 6 more aquarium UV sterilizer reviews from our picks.

1. Coralife Energy Savers ACL15600

This is a small UV sterilizer that can kill off algae and harmful microorganisms in the water and it can do so in fish tanks up to 125 gallons in size. Moreover, the Coralife is ideal for both salt and fresh water fish tanks.

It is rust proof, corrosion resistant and has been built with a double outer wall to make sure that it does not suffer water damage. This thing includes a powerful UV light that can keep your water clean and clear without question.

This is a fairly compact item that does not take up too much space inside of your tank, plus it is easily attached as well.


  • Ideal for up to 125 gallons.
  • Kills single cell algae and microorganisms.
  • Double wall to protect electrical components.
  • UV lamp included.
  • Small and compact to save space.
  • Easily attached.


  • Mounting system is quite fragile.

See more info and pricing at Amazon

AquaTop In-Line UV Sterilizer

Something that makes this such a great UV sterilizer choice is because it is very easy to connect.

This is an in line UV sterilizer that you can easily hook up to a water pump, the power head, or on the return line of your canister filter. It’s a versatile sterilizer that can be attached in a variety of ways to offer you with the versatility that you need. To make it even more versatile it comes with three different barb fittings too.

This particular sterilizer is intended for smaller aquariums so it's an ideal uv sterilizer for 10 gallon tanks as an example as it does have a maximum flow late of 105 gallons per hour.

However it does have a powerful 10 watt bulb that does a good job at killing microorganisms in smaller fish tanks. We do like the fact that it is a fairly small and compact sterilizer that does not take up too much space in the tank.


  • Ideal for smaller aquariums.
  • Can be connected directly to the pump or return line.
  • Powerful bulb.
  • Easy to install.
  • Maximal water to UV contact.


  • Does not have a solid case – risk of electrical exposure to the water.

See more info and pricing at Amazon

3. Aqua UV 15 watt Advantage 2000+ Hang On UV Sterilizer

This UV sterilizer is more than ideal for small and medium tanks and ponds of up to around 85 gallons in size. Something that we cannot forget to mention is that this thing is built in the U.S.A, so you know that it is a quality product. The Aqua Hang On UV Sterilizer has a fairly powerful 15 watt bulb that does a fantastic job at killing algae and other microorganisms.

We like this model because it hangs on the back of your aquarium inside of having to be inside of it, thus saving space for your fish to swim around.

Simply connect this thing to the return on your canister filter or to a separate water pump to make it work. On a side note, the pump should be able to process at least 500 gallons of water per hour.


  • Easy to mount.
  • Saves space inside of the aquarium.
  • Powerful 15 watt bulb.
  • Ideal for small and medium size aquariums.
  • Simply connect to the pump or return line.


  • Bulb life is limited.
  • Not ideal for coral tank.

See more info and pricing at Amazon

4. Green Killing Machine

The Green killing machine is a good little UV sterilizer that works well for tanks of up to 50 gallons in size. One of the things that we really like about it is that it is very easy to install and mount.

The whole thing is fully submersible and it features suction cups to easily attach to the inside of your fish tank. It’s convenient because it can be hidden behind other things to keep the aesthetic appeal of your fish tank intact.

The bulb itself is 9 watts, which is not overly powerful, but it does come in direct contact with the water, and moreover, the water flows along a zig-zag pattern to maximize UV light and water contact.

This thing is great because you can simply clip it onto any waterfall filter and let the water flow right through it. What we also like is that this thing has an LED alert which lets you know when the bulb needs to be changed.


  • Powerhead included.
  • Tons of UV to water contact.
  • Easy to install.
  • Suction cups for simple mounting.
  • No extra hardware required.


  • Fairly cheap plastic.

See more info and pricing at Amazon

5. SunSun UV Sterilizer Review

This is a convenient UV sterilizer to have for a variety of smaller fish tanks. The SunSun is ideal for tanks of up to 40 gallons in size, and it works for salt water, fresh water, and outdoor ponds too, thus making it quite a versatile choice.

What we really like about this model is that it does not require any extra pumps or hardware. The unit already includes a water pump that sends up to 132 gallons of water per hour along the UV light. Not needing extra equipment helps save you some money no doubt.

This model is also quite easy to mount. It uses suction cups to attach to the inside of the aquarium, plus it can be mounted either vertically or horizontally.

The SunSun also comes with a filter sponge do remove debris before the water gets to the UV light, thus eliminating as many harmful organisms in the water as possible.


  • Built in water pump.
  • No extra hardware required.
  • Easy to mount with suction cups.
  • Works for salt water and fresh water.
  • Ideal for small aquariums.
  • Can be mounted vertically or horizontally.
  • Submersible uv sterilizer with pump.


  • Will not work for large tanks.
  • Motor tends to burn out after prolonged use.

See more info and pricing at Amazon

6. Coralife BioCube UV Sterilizer

This is a special little UV sterilizer which is built specifically for the Coralife BioCube, but it does come with an adaptor so you can use it with other small fish tanks.

It does need to be noted that this model does only have a 5 watt UV light and is only suitable for tanks of up to 20 gallons in size, yet for small tanks it works just fine.

What we do really like about this model is that it is a free floating ballast unit that simply floats on top of the water.

All you need to do is hook it up to your filter pump’s out feed and let it do its job. This is quite an efficient and easy to use UV sterilizer.


  • Built for the BioCube.
  • Adaptor for other small aquariums.
  • Kills bacteria and organisms.
  • Simply let it float.


  • Fairly weak UV light.
  • Need a separate pump.

See more info and pricing at Amazon

What’s A Good Nano Tank UV Sterilizer?

If you are looking for a good small aquarium UV sterilizer, the AA Aquarium Mini Green Killing Machine is in our opinion a good option to consider. This particular item makes for a good UV sterilizer for a 5 gallon tank and slightly larger ones too.


One of the things that we like about this particular sterilizer is that it is fully submersible. It features a really tough shell that is sure to not let any water in, water that can cause electrical failure.

At the same time, this tough shell also helps to keep your fish safe from electrical currents.

The Mini Green Killing Machine is easy to mount. It comes with ready to go suction cups. Simply plaster it onto an interior wall of your aquarium and you are good to go.

You will know when it is time to replace this thing because it comes with an LED indicator which will tell you when it is time for a replacement.

What is quite impressive about the Mini Green Killing Machine is that it can handle up to 200 liters of water per hour. The power head it comes with pulls the water through the sterilizer for quick, high paced, and efficient sterilization.

What is pretty cool is that this filter also comes with a sponge to suck up even more debris from the water for an ultra-clean tank. The only real downside is that it can product a bit of noise at times but that’s pretty common with most Sterilizers from our experience.


  • Can handle a lot of water.
  • Easy to set up.
  • Does not require much maintenance.
  • Tells you when it is time for a replacement.
  • Solid shell – safe to use.
  • Fully submersible.
  • Comes with a filter sponge.


  • Makes quite a bit of noise at times.
  • Very hard to adjust the flow.

See more info and pricing at Amazon

Are Aquarium UV Filters Worth It?

The bottom line is that UV filters for aquariums are definitely worth it. At least, this is our opinion, but many others also share the same opinion. The bottom line is that there are tons of little organisms that can wreak havoc on the population of a fish tank.

Little viruses, bacteria, and parasites can all make your fish very sick, which is of course not a good thing. The light given off by the UV sterilizer kills off all of these pesky little microorganisms, and therefore helps to keep your fish safe and sound.

They are also extremely useful for killing algae. Algae is a big problem in aquariums because it takes up a lot of the nutrients needed by other plants.

At the same time, algae also takes up way too much oxygen that is needed by your plants and fish, There is also the fact that algae just does not look nice either.

Now, they might not be necessary for smaller tanks, but they are definitely useful for larger fish tanks, especially ones with a large bio-load with lots of plants and fish. Let's look at the overall pros and cons;


  • Kills algae.
  • Keeps aquariums clean.
  • Saves oxygen and nutrients for plants and fish.
  • Kills viruses and bacteria.
  • Keeps fish healthy.


  • Can be a little hard to operate.
  • Do not kill organisms that are NOT free floating.
  • May heat up the water too much.

Commonly Asked Questions

What is the best aquarium UV sterilizer?

In our opinion, the best UV sterilizer for aquariums would have to be the Coralife Turbo Twist 36 watt UV sterilizer.

This is a very large UV sterilizer that can be used for tanks of up to 500 gallons in size. It can be mounted right on the inside of the aquarium, or it can be mounted as an inline sterilizer using the included brackets.

It’s a large, easy to use, and durable UV sterilizer that will kill all sorts of algae and last for a long time to come.

What Is a inline UV sterilizer?

An inline UV sterilizer is simply one that is directly connected to the filtration unit. In other words, with some simple tubing, the output of the filtration unit is connected to the UV sterilizer.

This way, freshly filtered water coming out of the filter passes directly through the UV sterilizer when it leaves the filtration unit. It tends to be very simple yet also very effective.

Will a UV sterilizer kill good bacteria?

Technically speaking, if water with beneficial bacteria passes straight through the UV sterilizer, then yes, some bacteria may be killed.

However, for the most part, beneficial bacteria lives on rock, moss, on gravel, and other such places. In other words, most beneficial aquarium bacteria won’t ever make it close enough to a UV sterilizer for this to matter.

Does UV sterilizer kill ammonia?

No, UV sterilizers cannot kill or break down ammonia. In fact, those beneficial bacteria we discussed above are what kill ammonia.

A UV sterilizer, if used wrong, may actually kill the beneficial bacteria which take care of ammonia, thus achieving the opposite effect than is desired.

Will UV light kill algae in aquariums?

Yes, the whole point of UV sterilizers is to kill algae. It breaks down the algae so it can no longer absorb nutrients, grow, or multiply.

It’s specifically what UV sterilizers are designed for. That said, not all algae will be killed by UV sterilizers.

Is UV light harmful to fish?

For the most part no, UV light is not harmful to fish. The sun emits UV rays, and fish live just fine in the wild too, so there is no reason why it should harm them in an aquarium.

That said, if the amount of UV light greatly exceeds what they would normally get, then you may run into some problems, so make sure not to overdo it.

What size UV sterilizer for 125 gallon tanks?

A 24 watt UV sterilizer should be more than enough to clear the water in a 125 gallon tank of all algae, and it should only take a few days.

If you want algae to clear faster, you could turn the wattage up a notch or two, but it really is not necessary.

what size UV sterilizer do I need?

On average, for every 40 gallons of water in your aquarium, you will want roughly 7 to 10 watts of power from your UV sterilizer.

Do I need a UV sterilizer for 10 gallon aquariums?

Yes, you can absolutely get a UV sterilizer for your 10 gallon aquarium. There is no reason why you should not, especially when it comes to effective algae control.

Just remember that you only need a very small UV sterilizer for such a small tank.


If you need to ensure that your water stays clean and healthy for your fish to live in, you should definitely consider getting a UV sterilizer. They will kill a whole host of unwanted guests that have a tendency to invade fish tanks.

The best UV sterilizer for aquariums will be able to extend the life of your fish and make the aquarium look much more attractive too.