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Best submersible UV sterilizers – 2021 Reviews & comparison

Last Updated: 29.11.21


Top Submersible UV Sterilizers Reviewed & Buying Guide


If you are in need of a submersible UV sterilizer, you might realize that it is pretty difficult finding the perfect item for your needs, given the number of different products available on the market. In order to help you make up your mind, we have analyzed some of the top-rated devices and taken professional opinions and product specifications into account. We have come to the conclusion that the SUN Microsystems 9Watt is the product you should consider. This is a high wattage version, with an output of 9 Watts, so it is more efficient and productive. The integrated UV lamp ballast and single power cord design make it easy to use and compact as well, while the fluorescent lamp encapsulated in the quartz sleeve allows a 99% transmission rate to neutralize pathogens. Available at a very attractive price, the machine might be quickly sold out. In this situation, you might want to consider New Unbrand Pump Filter.


Finding the best submersible UV sterilizer implies knowing some important features they should have, before starting the actual search. Understanding how these aspects influence performance is important, and therefore knowing them will make it easier for you to decide. Learn what to look after by reading our comprehensive buying guide. And while we’re on this topic, you might also want to consider taking a look at our information on a reliable lab glassware washing machine or a high-quality ultrasonic jewelry cleaner.

Maximum capacity

Submersible UV sterilizers are devices that use ultraviolet radiation to eliminate germs and potentially harmful pathogens which might contaminate aquarium water or small garden ponds. These are highly effective in eliminating microorganisms such as algae too and are particularly useful if the fish you own have a weaker immune system.

Usually, they are characterized by the maximum capacity of the tank they can efficiently keep clean and sterile. Buying a product meant for a very large aquarium but using it inside a small tank will occupy precious space and will raise the water level, while, on the other hand, having a low-power UV sterilizer and using it for large quantities will reduce its efficiency.

There are products available for sale for all types of aquariums, no matter how large, professional items which can treat large quantities of water and disinfect it with great efficiency. These are recommended for big tanks, such as those found in biology museums or professional breeders. Pricier than the average household variants, these are rather bulky and might even be too large to fit your aquarium.

Usually, products for the everyday capacities belong to two categories: 75 gallons and 150 gallons. Both are pretty much similar in price, the main difference between them is how much water they can treat per hour. It is common to find 13-watt lamps in the larger and more powerful variants, while those for small tanks only use a 9-watt lamp. However, both are equally effective for their category.

You might also want to find out more about some tools that would allow you to take samples of water from the tank and have them analyzed, things such as small and accurate pipettes, reliable dropping pipettes or a versatile multichannel pipettor.


What is included in the sterilizer?

The sterilizer is only responsible for eliminating the pathogen agents from the water. It does this by using UV light, which effectively destroys them. In order to obtain an efficient sanitization, you have to recirculate the water and to also provide enough exposure to make disinfection powerful enough.

For this, you need a water pump and the subsequent tubing. Furthermore, to eliminate the debris that might reduce exposure, a mechanical pre-filter for trapping them should be installed to purify and clear the water before passing through the UV area. This would imply extra tubing and quite a headache.

This is why a modern good submersible UV sterilizer includes all these elements in the same product. Water is absorbed through the lower part, and the bars prevent debris from being sucked into the system. It is then circulated through a mechanical filter which traps larger particles, and only then does it pass through the front of the UV lamp, which sterilizes it.

Once the process is over, the water is pumped back into the tank, entering it through the nozzle. Adjustable flow sterilizers are a good choice too because they allow you to efficiently specify the amount of water to be processed in one hour.


Other features and budget

Other features which might be included with some products are suction cups to help you install them inside the aquarium, spare parts, and some tubing if it is required. Sometimes, spare lamps are included – these should be changed yearly, in most cases

Lock-on clips for easy filter removal and change, as well as for surface cleaning, are also provided sometimes. These make maintenance easier but do not influence the overall performance of the machine, as long as regular cleaning is done.

Professional sterilizers, however, used for large aquariums, can cost a lot more but these also include a lot of extras which might be useful in certain scenarios. It is recommended that you buy the product most suitable for your needs, in accordance with the capacity of your fish tank.



5 Best Submersible UV Sterilizers (Reviews) in 2021


It is impossible for us to pick up an item that will satisfy all your expectations and needs. In order to give you a helping hand, we have compiled a list of products, and wrote some reviews of submersible UV sterilizers which take into account customer feedback as well as product specifications. As objective as possible, these treat important aspects of these devices.



1. Sun UV Sterilizer Adjustable Pump Filter 


One of the products that came up most often while we were compiling our list is this useful and efficient water filter and sterilizer for larger aquariums of up to 150 gallons. It is compact and comes with an adjustable water flow regulating nozzle, making it pretty versatile too. It is a popular product amongst aquarium owners who want to have clear and sanitized water.

Suitable both for freshwater and saltwater, this device is fitted with an 8 Watt water pump and a 13 Watt UV light which sterilizes the water and eliminates most pathogens causing diseases. No additional tubing or circulation pump is therefore required, meaning that it can also be used in a small garden pond.

Controlling microorganisms and free-floating algae, it provides clear and sterile water which improves the health condition of your fish. It includes UV ballast and suction cup mounting brackets used to attach it to the interior walls of your aquarium. Installation can be done in a vertical or horizontal position.


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2. SunSun JUP-01 UV Sterilizer Submersible Filter Pump


Simple and effective control of harmful pathogens that might be found in the water inside your aquarium and of free-floating algae and other microorganisms can be achieved with the Sun Sterilizer. It includes everything you need to start operating it straight away, and it is affordable too.

The compact design of this unit is a feature which makes it attractive to most customers, being easy to install and fit inside a tank. Furthermore, it requires no additional tubing or circulation pump since everything you need is included in the product.

It features a large mechanical filter sponge which captures debris to increase exposure to UV radiation. The pump directs the water towards the lamp for clean and pathogen-free aquarium water. It can be installed in a vertical or horizontal position inside the aquarium and is suitable for freshwater and saltwater too. Suction cup mounting brackets are included too, so you can install it straight after unboxing.


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3. Generic Polar Aurora 3310


A more powerful device for larger aquariums or garden ponds is the Polar Aurora UV Sterilizer with a submersible filter. Great for aquariums of up to 150 gallons, it will provide and maintain clear and sterile water, free of any harmful microorganisms or algae which might cause health problems for your fish.

The built-in mechanical pre-filter traps all debris and makes sure that the water entering the UV lamp area is clear of any residual matter that might reduce exposure to the radiation. The water pump recirculates it and no additional tubing is required. Once it has bypassed the lamp section, many germs are killed by the radiation, and you will obtain clear and sterile water inside your aquarium.

Included are suction cup brackets for an easy installation inside the fish tank, either in a horizontal or vertical position. The flow can be adjusted, diverting it to a direction of your choice. Customers appreciated its reliability and the low maintenance required which makes it a good choice for someone with little time on his or her hands.


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4. Polarbear’s Pet Shop New Aquarium Submersible Fish Pump Tank UV Sterilizer


This newer design is great for preserving the water inside an aquarium clean and sterile. Available at an affordable price, it is appreciated by customers not only for its reliability and functionality, but also for having great value for the money. Featuring an adjustable flow rate, it allows the user to make the settings, controlling how much water is treated in a period of time, maximizing the effect.

A pre-filter is included, to remove dust and debris and increase the level of exposure to UV radiation. The device is fitted with a 9-watt UV lamp and an 8-watt water pump, ensuring a maximum flow of 211 gallons per hour.

Meant for aquariums with capacities of up to 75 gallons, it is a compact design for the everyday household fish tank. Included in the package is a UVC light bulb, suction cup mounting brackets and air tubing, to make sure that it is ready for operation and installation right after you unbox it.


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5. Sun Microsystems 


Definitely one of the customers’ favorites, this compact and efficient sterilizer is a great option for someone who does not need excessive power and is not willing to spend a fortune on a great, high-quality item. It is also available for a great price, which overall gives it a good value for the money spent.

In order to sterilize the water, it uses a compact UV fluorescent lamp built in a quartz sleeve which is airtight, allowing a very high transmission rate. It helps greatly in eliminating disease-causing germs or bacteria. The integrated pump and mechanical pre-filtering sponge are useful in eliminating small particles such as sand or dust, making the water look clear.

After the water has been circulated through the particle filter to trap debris, it is directed towards the UV without any bypass. The sterilizer features a quick-release cap mechanism which provides easy access to sponge replacements and regular cleaning schedules. Removing organic matter that might build up on the quartz sleeve is also simple and fast.



» Check the information from past years

If you want the best UV sterilizer for freshwater aquariums, but you have little to no time at your disposal, this paragraph will help you out. We conducted thorough research on the topic while taking into consideration feedback from buyers, expert opinions, and social media comments. The product mentioned most often and praised by users is the New Unbrand 13W, a model that offers excellent performance for a decent price. The good news is that this model works for both freshwater and saltwater aquariums. The unit is compact and easy to install, two reasons for buyers to consider this above other similar models. The integrated UV light will take care of all the tiny critters living in the water, to keep the aquarium clean and suitable for your fish. If the New Unbrand 13W is no longer available, the second suggestion we have for you is the Sun 9W, a unit that is almost as good.


Taking care of your fish entails a lot more care than you would put in monitoring the health of other pets. For instance, you can use a pet thermometer to determine if your little friend has a fever, but you cannot do the same thing with all of your fish. The best course of action is to prevent disease, by installing a sterilizer in the tank. We are here to help you figure out which ones are the best choice for you.


The power of the UV light

If you take a close look at what the sterilizers available on the market have to offer, you will notice that they all work with a UV light that has a certain wattage. That is the power of the light bulb. The more power the light has, the better and more efficient the sterilizing work it will carry on.

Of course, this does not mean that you should overspend only because a certain UV sterilizer has superior wattage for its light bulb. You need to find a suitable option for your aquarium at home, and if you only have a small unit, you should pay too much on a sterilizer that is simply too powerful.

Think about what characteristics you bear in mind when you purchase a microscope kit. If you need a powerful model, for extensive research, you should invest more in one. But, if you don’t intend to do more than just school research, spending too much would be a bad idea.

The same principle applies when you look at different sterilizers for aquariums. A small aquarium does not need a very powerful model. The best freshwater tank UV sterilizer is the one that can be used for the exact needs of the aquarium you have. The good news is that you can choose from various products available for sale, and one is surely a good pick for you.


A hang-on unit or an inline sterilizer?

While shopping around for a UV sterilizer for your fish tank, you may notice that some models are advertised as being hang-on units, while others are said to be inline sterilizer. What do these terms mean and why is it important to understand them?

A hang-on unit is a sterilizer that you simply hang over the tank. The unit must not have its UV light in contact with water, and it does its job from above. The inline type of unit can be immersed in water. You will notice that manufacturers will advertise which models are submersible and which are not.

Besides the way of employing the sterilizing light, there are not many differences between the two types. You can opt for one or another, without fearing that you might be sacrificing much. These two types of UV sterilizers are available in all pet stores and online, and you can easily take your pick.


Does the sterilizer kill bacteria, too?

You don’t need a lab cabinet and all the equipment you can put in it to examine the bacteria that might live in the water of your aquarium. The best course of action is to find a model that is capable of killing all the nasty microorganisms that exist there.

Do not settle for a model that just eliminates algae. Remember that the health of your fish depends on the care you invest in them. A reliable UV sterilizer will do a great job against bacteria, too, so that your pet fish can enjoy clean and clear water all the time.



5 Best UV Sterilizers for Freshwater Aquarium (Reviews) in 2021


With so many UV sterilizers available on the market, making a sound investment sounds like a tricky task. We want to help you out by offering you a quick selection of models that have so far proved to be popular among freshwater aquarium owners.



1. Sun UV Sterilizer Adjustable Pump Filter


The New Unbrand 13W is an excellent choice for anyone who wants to have an aquarium with clean and clear water without working hard on maintaining it that way. Ideal for both freshwater and saltwater aquariums, it is reliable and offers superior performance.

For lab equipment, you need items made from neutral glass, but when purchasing a sterilizer for your aquarium, there are other things you need to bear in mind. This model has a 13W light bulb that is capable to sterilize 150 gallons of water without a glitch. You get a water pump with your purchase, and the water flow can be adjusted.

Many buyers consider this a good sterilizer for freshwater aquariums, and for all the right reasons. This model is an excellent method to control the growth of bacteria and algae in your aquarium. It is easy to install, and it works even for garden ponds, with the same efficiency.



The 13-watt bulb is one of the biggest pluses of this model, as it is more powerful than what you can normally find on the market.

You will not have to worry that this model won’t work for your setup, as it is made to work with saltwater and freshwater tanks alike.

Its water pump does a great job and helps circulate the water so that the fish living in your aquarium get not only clean water but also the necessary oxygen to survive and even thrive.

Should you decide to use this model for a garden pond, you will be pleased to discover that it works for such setups, as well.

You won’t encounter any issues with installing it, as the manufacturer provides clear instructions in this respect.


The fact that this model is made from plastic might not make you have a lot of trust in its durability, but, so far, those who bought it seemed reasonably pleased with it.

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2. Sun 9W


Another model praised by the reviews of aquarium UV sterilizers, the Sun 9W is an excellent pick, if you need such a device for a tank holding 50 to 150 gallons of water. The maximum water flow is 210 gallons per hour, so you can easily notice that the water in your tank will be cycled and filtered, so that your fish get fresh water all the time.

The model comes with a water pump that keeps the flow going, as well as an UV light. The 9-watt light bulb is responsible for the sterilizing work that will be conducted once you install this sterilizer in your aquarium. Another good thing that can be said about this model is that it is suitable for both freshwater and saltwater tanks.

You can easily install the unit in a vertical or horizontal position. Everything you need for easy installation is provided with your purchase.



Any tank between 50 and 150 gallons will work well with this UV sterilizer that is designed to handle such quantities of water without a problem.

With a water flow that reaches 210 gallons per hour, you will know that the fish in your aquarium will get clean water full of oxygen.

Equipped with a 9-watt bulb, this unit manages to sterilize important quantities of water, to stop the growth of bacteria and algae in your fish tank.

It doesn’t matter if you have fish that live in freshwater or saltwater; this sterilizer works great with both types, and you won’t find much to hold against it.

Installing the unit in a vertical position is easy, but, if you choose, you can mount it in a horizontal position, and it will still do its job.


Some people say that they found the instructions regarding the installation to be confusing and that some guessing work was involved in the process.

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3. Odyssea CFS 700 Aquarium Canister Filter UV Bulb


The Odyssea CFS 700 is considered among the must-have items if you have a freshwater tank, a saltwater aquarium or a coral reef in your care. The capacity of pumping 700 gallons of water per hour is outstanding and gives you a clue about how reliable this model is. 

This canister filter can be used, as shown above, in different setups. You will not have to worry a bit about installation. The manufacturer does not only provide all the hardware needed for making it simple, but also all the instructions.

The filter comes along with a 9-watt UV light that will take care of all the microorganisms and algae growing in your fish tank. If you are wondering what is the maximum capacity aquariums it can handle, that would be 125-gallon setups. The silent operation is a big plus, and you will not be disturbed by it when you try to rest in another room.



For aquariums that reach 125 gallons in size, this model is ideal as it manages to deal with important water quantities without an issue.

As a filter, it is great that it can circulate up to 700 gallons per hour, and you won’t ever have to worry that your fish don’t receive the care you want to ensure for them.

Should you decide on different setups, it won’t be an issue, simply because the manufacturer thought in advance about this and ensured that all configurations are possible.

As it is quiet, it is a better choice than many others on the market, and you will not have an issue with installing an aquarium close to areas where people are resting in your home.


Some issues with the hose were mentioned by a user who said that he needed to have the hose replaced with some difficulty.

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4. Odyssea Ultraviolet Sterilizer Lamp Aquarium Filter


For a working fish tank sterilizer, you don’t need a magnetic stirrer, but you need a bulb that works. The good news is that most of the products you see on the market can have their bulbs replaced, and that is even recommended, after a certain period of time. For instance, many fish tank owners prefer to change the light on their sterilizers at least once a year.</p>

<p>This 36-watt UV bulb is an excellent choice when you need to replace the one you have. You don’t have to worry that this bulb will not be a good match for the unit you have at home. It is designed to work with most units available, so it is pretty much an universal model.

However, in case you still don’t want to end up spending money on something you are not going to use, you can always contact the manufacturer and ask about compatibility issues.



Ultraviolet rays are efficient in removing the growth agents for bacteria and algae from your pond, or aquarium, and that’s what this unit delivers efficiently.

This product is a bulb that can be used to replace the one you have on your sterilizer so that you won’t have to buy another sterilizer altogether.

Due to its high power – 36 watts – it is reasonable to think that you will be able to ensure proper sterilization for the water in your fish tank.

Since it is universally compatible with most UV sterilizers, you won’t encounter any issues with it not working with the unit you already have at home.

You will be able to save some cash by purchasing a replacement bulb like this one that could work for more than a year without significant issues.


You might not need such a powerful bulb, especially if your unit runs typically on a bulb that has fewer watts than this one.

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5. Odyssea UVC Ultraviolet


This 9-watt bulb is made for the Odyssea UV 9 and the UV Pro 9 models, so do not purchase it, if you do not already own one of these models. As you can see, it is a low wattage model and you should buy it if this is the power capacity you need.

As you may well know, low wattage is recommended for small aquariums, because the UV light used for sterilizing needs to be able to cover a certain area, to offer good performance. That is why you should always make an informed decision, and read first the specs on your unit, to see what kind of bulb is needed.

All the sterilizers on the market need replacements. That is why it doesn’t hurt to purchase a few and have them stored for the times when you need to use them. This good quality bulb is an excellent option, if you already have an Odyssea sterilizer.



If you have an Odyssea UV sterilizer that works with 9-watt bulbs, this replacement is a pretty good deal that will prolong the life of your unit.

Like all the products made by this company, this bulb is of high quality, and you can expect excellent performance from it

Designed to last, it is an excellent purchase if you want to make sure that your UV sterilizer is never out of order.

Seeing how it is decently priced, you may find it a good idea to store a few spares for all the times when your sterilizer needs a replacement, and it helps to have one at hand.

For small aquariums, this low-wattage bulb is all that’s needed, as the UV rays emitted will be powerful enough to stop the growth of bacteria and algae.


It is crucial to notice that this model is only compatible with the UV sterilizers of the same wattage from the same manufacturer, so you might be limited in your choices.

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Ioana Moldovan

Ioana’s professional experience in the optics field has helped her understand the value of passing her knowledge forward. Her curious personality helps her gather useful information for her readers and her goal is to make technical information fun and accessible to everyone.

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