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The Best UV Sterilizers for Aquariums in 2022

best uv sterilizer for aquarium

Partly due to the global pandemic, people are now somewhat familiar with UV sterilizing equipment. You will be using UV light to kill unwanted bacteria, viruses, and other microorganisms. What you might not know is that you can also use a UV light on your aquarium to keep the water clear and free of bacteria and algae blooms.

If you want to get the best UV sterilizer for aquarium, and not just a product that claims to sterilize the water, this guide might help you. You might be wondering why you would use the best aquarium UV sterilizer on your aquarium. Would it not also kill the beneficial bacteria that is in there?

The reason why UV sterilizers are viable is their placement. Most of these products do not directly shine light into the tank. Not only will doing so kill all the microorganisms, beneficial or not, it will also kill the fish, plants, and all living things.

You can typically install these sterilizers in line with the filtration system. This will allow the UV light to kill the bad bacteria that usually hang in the water while leaving the beneficial bacteria alone because those usually hang around the surface.


Best UV Sterilizer for Aquarium Reviews

1. Fluval in Line UVC Clarifier

fluval in line uvc clarifier

My aquarium had a rather serious case of bacterial and algae blooms before I used this product. It was so bad that even complete water changes did not help make the water look even halfway clear.

I tried this UV water sterilizer and after just one day, I saw a dramatic improvement in water quality. After a week or so of using the UV light for a couple of hours a day, the water was crystal clear.

Aside from the pesky bacteria that cause the water to become cloudy, this product also prevents the growth and spread of the deadly cyanobacteria. I had a tank that unfortunately got hit badly with cyanobacteria. Thankfully, this product was able to fix the problem before all the fish and plants died.

I have a Fluval filtration system set up in my tank, so getting this inline UV sterilizer aquarium to fit was a problem. The outlet hose is the same size as the inlet of the UV sterilizer so I did not do any modifications. The installation was also quite straightforward. I also like that this device comes easily hidden in the aquarium cabinet.

Supposedly, the UV bulb can last for at least 30,000 hours of use. If this is accurate, you will be using this best nano UV sterilizer for a very long time. I use mine for around 2-3 hours every day for maintenance purposes. If this can last for 30,000 hours, that means I can use this UV sterilizer for at least 27 years.

Now, it would be great if this ultraviolet sterilizer for fish tank could last almost 30 years, but we all know that it won’t happen. The problem is that in case the bulb gets damaged for any reason, you can’t replace it as it is completely sealed and cannot be opened. You will need to buy a new one in case a component gets broken.

  • Effectively kills algae and bacteria in the water column
  • Prevents the growth and proliferation of deadly cyanobacteria
  • Should easily connect with Fluval canister systems
  • The UV bulb can supposedly last for 30,000 hours
  • Keeps tank water clean without using chemicals
  • Comes in a completely enclosed system that does not allow bulb replacement

This best submersible UV sterilizer should supposedly be easy to install in all Fluval systems, but it only fits most of the 07 and 06 series. So, if you don’t have any of those systems, you will need to purchase additional fittings to make this UV sterilizer work for you.

2. 5W UVC Aquarium Clean Lights

5w uvc aquarium clean lights

One of the things that I liked about this device is that this does not require any kind of installation. I have a sump system installed in one of my tanks, and I placed this UV lamp in one of the compartments, two spaces away from the biological filter. I can say that it works as expected.

You cannot tell how durable this UV sterilizer for planted aquarium is just by looking at it, but believe me when I say that this is one tough UV lamp. The glass housing is thick, and it would take a hard hit to crack it. I haven’t dropped mine, but just holding it in my hand, I can tell that it is quite durable.

This UV light is quite potent. It helped clarify my aquarium water in just a couple of days. I overfed my fish one time and it resulted in a bad case of bacterial bloom. Even partial water changes did not help. I tried this as a last-ditch effort before using chemical methods and it helped quite a lot.

Another neat thing about this UV sterilizer is that the installation process only requires you to stick the suction cups against the glass of the sump or filter. You do not need to do any plumbing or anything like that. Just position the lamp, plug it in, and turn on the light.

Now, the problem with this device is that your result may vary from that of others. I use this device in two of my tanks, and the rates at which the water cleared up are different. Don’t expect your bacterial or algae bloom to go away as fast as some fish tank UV sterilizer reviews say. Still, I can say that it will work, that is for certain.

  • Submersible and will fit most sump systems
  • Robust construction, which means that it will not break that easily
  • Efficiently kills bacteria and algae without using chemicals
  • Easy to install and comes with suction cups and brackets
  • Works for both freshwater and saltwater aquariums
  • Results may vary, though, you can still expect water clarity overall

The one thing that you need to avoid is to have any of the UV light leaks out. Most importantly, do not expose your aquarium directly to UV light. You need to have a filtration system that has a chamber where you can place this device.

3. SunSun Hw303B Canister UV Sterilizer Filter

sunsun hw303b canister uv sterilizer filter

The best thing about the SunSun Canister Filter kit is that it is the only thing that you will need to keep your aquarium clean and clear. This top UV filter for aquarium is a biological filter, mechanical filter, and UV sterilizer all in one device.

I use one of these to keep one 70-gallon tank clean. There is also another one in the garden to maintain a small koi pond. It has several purposes even if the SunSun UV sterilizer is not that large it can contain quite a lot of filter media.

When you buy this canister filter, it will already come with a pound of filter carbon, a pound of ceramic rings, and a whole bunch of bio balls. There are also several filter pads. This means that even the smallest bit of debris will not be able to go through.

The thing I liked the most about this canister filter is that it has a built-in ultraviolet lamp. This allows the filter to not just remove solid waste in the water, but also kill floating germs and bad bacteria. I turn on the UV light for a couple of hours every other day whenever the tank gets cloudy because of bacteria or algae blooms.

I have this filter hooked up to a 70-gallon tank, but it is strong enough to handle up to a 100-gallon tank if needed. This has a pump that is capable of up to 370GPH flow rate. This allows the water to circulate and get oxygenated properly, thereby resulting in healthier fish.

Aside from being a bit expensive, which is subjective, there is nothing to complain about in this UV sterilizer freshwater aquarium. Ever since I started using this device, my aquarium has always been clean and clear. The fish and other aquatic creatures are all healthy and happy. If ever this filter fails eventually, I will surely buy another one.

  • Comes in an all-in-one filtration system
  • Capable of holding a lot of filter media
  • Has a built-in UV light sterilizer
  • Comes with free bags of filter media
  • Can work for aquariums as large as 100 gallons
  • There is nothing to complain about – This is one of the best canister filters that you will ever find

Although this all-in-one canister filter is a bit on the expensive side, it will be a good investment on your part. Aside from the fact that this device does a great job at cleaning the water, it is also very durable. I have read a lot of reviews saying that their devices lasted for years without any repairs.

4. Coralife BioCube UV Sterilizer

coralife biocube uv sterilizer

As its name suggests, this is a small UV sterilizer aquarium, which allows it to fit perfectly in small aquariums such as the BioCube. This sterilizer comes with a 5-watt UV bulb, which might seem small. However, it is just the right size for small aquariums. Anything bigger than that will just be overkill.

A nice thing about this sterilizer is that it is not technically proprietary for BioCube. You can use this device even if you own another brand of tank or filter system. This comes with a universal adapter and extra bits of tubing to make it fit on any kind of water pump that you may be using.

This kit comes with a long-lasting, 5-watt UV bulb. Aside from the bulb being able to last a long time, it is also nice that you can easily replace the bulb if ever it gets damaged, or burns out because you forgot to turn off the light and you let it run for an entire day.

I am quite happy with this device because ever since I started using it, I have yet to experience any bacteria or algae blooms. It also killed all the harmful parasites, thereby keeping my fish and plants healthy.

Although it is possible to just replace the damaged or burnt-out bulb, it is more cost-effective to just buy another unit. The replacement bulbs are hard to find, and they cost almost as much as an entirely brand-new UV sterilizing kit instead of trying to salvage your old one.

  • The compact size makes it perfect for small aquariums
  • Comes with a universal adapter so it can work with other brands
  • Features a long-lasting UV bulb that you can also replace when necessary
  • Easy to install
  • Effectively kills bacteria, algae, and parasites in the water
  • Replacement bulbs are almost the same price as a new unit

Even if you don’t own a BioCube aquarium, you can still use this filter attachment thanks to the universal adapter and extra bits of hose. It is unfortunate, though, that replacement bulbs cost almost the same as a complete unit.

5. GRECH CBG-800 UV Sterilizer

grech cbg-800 uv sterilizer

This HOB filter is perfect for 20- to 50-gallon aquariums, but it can also work with smaller tanks – up to 15-gallons I suppose. I use this on a 20-gallon tank and I am loving its compact design.

Another thing I liked about it is that it already comes with a built-in UV light. This HOB comes with a 5-watt UV light, which is strong enough that it can kill most of the bad bacteria, algae spores, and parasites suspended in the water.

I also liked that you can set the parameters of this filter any way you like. I have a 20-gallon tank, so I need to dial down the flow rate almost to the lowest point because the pump is stirring up the water too much. The telescoping water intake is also a plus. I adjusted mine to almost touch the bottom to greatly reduce the water disturbance.

This filter also comes with a surface skimmer, which is handy if you use a water conditioner that contains aloe. Although I rarely use this feature in my tanks, since surface film rarely happens in freshwater aquariums, it is nice to know that it is there if I ever need to use it.

The makers tried so hard to innovate this device that it became complicated. For instance, if you need to clean the filter, you will need to remove the entire filter basket. You will then have to remove the filter media carefully. After washing them, you need to align them perfectly; otherwise, the bag will not go back into the housing.

  • Has a compact design
  • Has all your filtration needs covered
  • Comes with a built-in 5-watt UV lamp
  • Adjustable flow rate and telescoping inlet tube
  • Features a surface skimmer
  • The over-engineered design makes it complicated to maintain

Although this filter can be quite tricky to maintain, it works quite well at removing all the nasty stuff in the water. The built-in UV light also worked in preventing algae and bacterial bloom. I highly recommend this for all aquarium owners.

6. Polar Aurora Canister UV Sterilizer Filter

polar aurora canister uv sterilizer filter

For such a powerful canister filter system, I was quite surprised at its compact size when I first got it. The base is just 9” by 9”, which makes it easy to stow away inside the cabinet of the aquarium. However, don’t be fooled by its size. It is powerful enough to circulate the water in a 75-gallon tank efficiently.

I also appreciated that Polar Aurora already included all of the filter media this canister filter will need to get started. The kit comes with a couple of fine and coarse sponge filters, a 1-pound bag of activated carbon, a pound of ceramic rings, and 40 pieces of bio balls.

Another quality of this device that I liked quite a lot is that it is so quiet. When I first used this cartridge filter, I thought I got a defective item because aside from the indicator light, I was not able to tell if it was working. It was that quiet. I placed my aquarium in the living room, so having a quiet cartridge filter was important for me.

This UV lamp is so strong that it can instantly kill bacteria and algae spores that are floating in the water. I used this canister filter system on one of my tanks that had a serious case of algae bloom. The water was so green that you cannot see the other side of the tank.

After using this filter for around 3 days at 3 to 4 hours a day, the water got much clearer and the green tinge was gone.

I have no complaints about how the device works, but I do wish that the plastic fittings were a bit more robust. I accidentally cracked one of the bolts that held the inlet hose in the tank and finding a replacement was a bit difficult. I just used an aquarium-safe superglue on it and hoped that it would hold.

  • Compact product – It barely uses a square foot of space
  • Comes stocked with filter media
  • Operates quietly and without any noticeable vibrations
  • Features a strong 9-watt UV bulb
  • Has a respectable flow rate – It is powerful enough for a tank 75-gallons in size
  • The plastic fittings are flimsy

There is nothing much to complain about regarding this canister water filter. It has a decent flow rate, a large capacity for filter media, and a powerful UV lamp that can kill all kinds of unwanted microorganisms in a split second.

7. TAISHAN UV Sanitizer Submersible Light

taishan uv sanitizer submersible light

The Taishan submersible UV light bulb for aquarium is one of the smallest UV sterilizers that I have used as of yet. It is small enough that it can fit in a HOB meant for 20–gallon to 30-gallon aquariums. You just place this light in the compartment that is the farthest away from your biofilter – that is if you already have one.

Aside from its miniature size, this little gadget also comes with a bracket and suction cup. This means that you can place this device securely against the wall of the water filter chamber. Make sure to secure this device as the glass housing is quite fragile.

Another thing I liked about this submersible UV sterilizer aquarium is that it comes with a built-in timer. I liked it because I could just turn on the light and set the timer for an hour, and it would turn off on its own. This is quite unlike other UV lights I have used where I have to set a timer to remind me to turn them off.

The best thing about this UV sterilizer, in my opinion, is that it uses UV-C light. It is much more effective at killing harmful microorganisms. Unlike other UV lights that needed to be on for a couple of hours every day, my UV-C light only required 30 minutes every day for a significant increase in water clarity.

I have nothing to complain about regarding how this gadget worked. However, if I need to point out even just a minor issue, it would be that the instructions that came with the device were hard to understand because they were written in severely broken English.

  • Miniscule size makes it perfect for small tanks
  • Easy to position for maximum effect
  • Comes with a built-in timer
  • Uses UV-C light, which is more efficient at sterilizing compared to regular UV light
  • Can kill not just harmful bacteria but also algae spores and microscopic parasites
  • Quite hard to understand and comprehend instructions

If you always had problems with bacteria and algae blooms, you need to check out this rather simplistic device. This tiny light was able to turn my once algae-infested tank into one that looks almost crystal clear in less than a week.

8. VIP UV Sterilizer Aquarium Filter

vip uv sterilizer aquarium filter

This water filter/sterilizer has a rather strong flow rate, up to 200 gallons per hour, so it is not advisable to use this in a tank with small and light fish. On the other hand, this works just great for my 75-gallon planted tank. The water circulates quite well, but it is not strong enough to uproot my plants.

The reason why it is one option for the most suitable UV sterilizer for saltwater aquarium is that it is both a filter and a UV sterilizer. This means that there is no need for a separate UV sterilizer for your aquarium setup. This does not just catch the solid waste particles in the water but also kills harmful bacteria and other microorganisms.

Unlike some of the other UV sterilizers that I have used before, this one was quite easy to take apart for cleaning. There are no screws to undo. There are only a couple of pieces to keep track of. The UV lamp is also easy to remove and replace when needed.

Speaking of the UV lamp, this device comes with a powerful 9-watt bulb. Any undesirable microorganism exposed to UV light will instantly die. I was worried that it would also affect my fish and shrimps but I am glad to say that there is a proper shield for the lamp. I haven’t seen any evidence yet of the UV light leaking out into the tank.

This UV light sterilizer for aquariums is at least a foot long, so you may not be able to use this properly if you have a small or shallow tank. It is also quite bulky for a submersible filter, so hiding it within the tank decor will be a challenge.

  • Excellent flow rate, making it ideal for tanks 50-gallons and above
  • Serves as an all-in-one device – It filters the water and kills all harmful microorganisms
  • Easy to dismantle and maintain
  • Has a powerful 9-watt UV light for purifying the water
  • Aerates and circulates the water
  • Much bigger than it looks in the pictures, which means it is not ideal for small tanks

This is an option for the most beneficial UV sterilizer for reef tank if you have a large tank (50-gallons and above) and you are not keeping small fish because the pump might blow them away. If you have a small aquarium, like a 20-gallon tank, then it might not be deep enough to submerge the device completely.

9. OXYFUL UV Ultraviolet Clarifier Lamp Filter

oxyful uv ultraviolet clarifier lamp filter

One thing I liked about this UV light sterilizer is that it does not disrupt any current filter setup. It was years before I learned about UV sterilizers and how they prevent algae blooms. It was nice to know that I could just install this one in line with my filter system and that I don’t need to replace everything.

Another benefit of using this brand is that you can use it on any aquarium filter system that you have. It has plenty of adaptors so it can fit on any rubber hoses that you may be using. You can also set it at any position you want. The cabinet of my aquarium is already quite cramped so I had to mount this device vertically and it still worked.

This filter attachment can also handle quite a lot of pressure. I have a large 100-gallon tank, so the water pump needs to be quite strong as well. This device has a rating of 792 gallons per hour, so the strength of the pump was not even a problem.

Also, even if water is passing through this device at a fast rate, the included 18-watt UV light ensures that every trace of bacteria, algae, and other nasty stuff will be rendered lifeless as soon as they get exposed to the UV light. I have not experienced algae blooms since I started using this device, and I bet that you won’t as well.

The device itself worked quite well for me, but I did have a minor issue with the included O-rings. The ones that I got were quite weak and brittle – two broke in half and the others were leaking. It is a good thing the manufacturer was gracious enough to send me a lot of spare O-rings when I sent them an email detailing my problem.

  • Installed in line with the tank’s filter system
  • Comes with lots of different fittings for all hose sizes
  • Can handle high flow rates
  • Has a strong 18-watt UV bulb
  • Ensures water clarity and health
  • The O-rings are not durable and flexible enough

The only issue that I had with this UV water sterilizer is that it has weak O-rings. It would not even be that big of an issue if the parts were easy to find. Thankfully, the manufacturer has excellent customer support and aftermarket services. I highly recommend this UV filter for any aquarium that uses a sump.

10. SunSun HW-304B External Canister Filter

sunsun hw-304b external canister filter

If you have a large aquarium, like something over 100-gallons, get this canister filter for your setup. This filter has a water pump that is capable of 525 gallons/hour, and it had no problem circulating the water in my 150-gallon reef tank. I positioned the intake pipe low, almost touching the substrate, to make sure that the water circulates properly.

This canister filter uses 5-stage filtration, so you can bet that it can remove almost every bit of debris floating in the water. This will keep your water clear and greatly reduce the chances of ammonia and nitrate spikes in the water. However, even though the water is still clear, I make it a point to test it every week, and so should you.

Aside from the solid waste particles, this canister filter also comes with a strong 9-watt ultraviolet lamp to kill bacteria and other harmful microorganisms that float in the water. If you are having trouble with green water due to algae bloom, then you need to try using this product.

For something that circulates water at a high rate, I liked how quietly this filter worked. Even in my quiet living room and with the cabinet door open, you can hardly hear it running, aside from the gentle trickling of the water in the tank. The sound of the water pump even goes away when I close the cabinet door.

I like this canister filter a lot, but I would have liked it even better if the instruction manual that came with the device was written clearly. It was a good thing that the manual came with illustrations because the instructions were written in broken English and were quite hard to understand.

  • Has a high flow rate
  • Compact design, making it easy to stow away
  • Quiet operation
  • Comes with a built-in 9-watt UV bulb
  • Already comes with all the filter media needed to get started
  • Quite hard to understand instructions

Just like its smaller variant, this canister filter can also move a large volume of water despite its rather small size. However, if you have a tank that is smaller than 50 gallons, I suggest using the smaller model instead of this one. This might be too powerful for a small tank.

What to Look For When Buying a Uv Sterilizer for Aquarium

best submersible uv sterilizer

There are lots of brands of UV aquarium sterilizers in the market today, but not all of them work the same way. Some of them do not even work at all. To make sure that you will not be wasting your time and money on the wrong products, here are some of the factors you should consider when shopping for a UV sterilizer for aquariums.

Strength of the UV Lamp

This will depend on the flow rate of your water pump. If you have a fast flow rate, then you need a stronger bulb. I would recommend anything 9-watts and above. It is often the case when you have a big tank. On the other hand, if you only keep a small tank, like a 15- or 10-gallon aquarium, a 3-watt bulb will suffice.

Built-in or Needs Installation

If you will be starting a new tank, consider getting a filtration system with a built-in UV lamp. It will save you a lot of time and space. On the other hand, if you already have a filtration system in place, you can get one of those submersible UV lamps, or those you install in line with the filter system.

Ease of Use

The built-in UV lamps are the easiest to use. It is mainly because you do not need to position them where they will not hurt the bacteria in the biofilter, but will still be treating the water going through the system. However, most filters with built-in UV lamps do not have timers, something which submersible lamps have.


If you have a very limited budget and you cannot afford to replace your entire filtration system just for the UV sterilizing capabilities, then you should get a submersible or inline UV lamp. This should work the same way, but without breaking the bank.

Frequently Asked Questions

best uv sterilizer for planted aquarium

What Size UV Sterilizer do I need for my Aquarium?

If you have a large tank and your water pump has a high flow rate, you will need a UV sterilizer that has a 9-watt or stronger UV lamp. For a small tank, you can make do with a 6- or 3-watt bulb.

Where to Place UV Sterilizer in Aquarium?

The one place where you should not place your UV sterilizer is inside the tank, or anywhere that the light from the lamp can get into the tank. This will kill your fish. The best place to place your UV sterilizer is inside the box filter.

It may also be in a compartment that is away from the biological filter. If you have a sump, get an inline UV sterilizer and connect it to the return hose.


Sometimes, mechanical filtration is not enough to keep your aquarium clean and clear. Despite how many stages of filtration that your aquarium water goes through, bacteria and algae will still pass through them.

If you want clear and healthy water for your aquarium and its denizens, you will need the best UV sterilizer for aquarium that you can find. With this device, you will no longer need to use harsh chemicals to clarify the water in your tank. The UV light will do it for you naturally.

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