5 Best UV Sterilizers for Aquariums

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If you own an indoor aquarium, you probably want your water environment to be always clean for your fish life. Actually, this is a necessity for most fish species.

Usually, cleaning the water requires a good water filter, that does mechanical, chemical and biological water filtration. This is a must, no matter what type of aquarium or fish breeds you possess.

However, there is another device, that can help clean the water even better (if used in sync with a filter). This device is called a UV Sterilizer. In this article, we’ll talk about 5 different products that are all UV sterilizers.

You’ll see what they do and what you get in the package with each separate item. You should know, that no matter which one you’ll choose in the end, it will do the job, because all 5 are quality products.

After that, I will tell you how the work in general and how to install one in your tank as well. Let’s start with the first device on the list:

1. Coralife Turbo-Twist

This product is found on Amazon, just like all the others. It comes in 3 different versions, for different needs.

All 3 versions are designed to sterilize a different quantity of water. The first type, that is best for a smaller fish tank, can work with up to 2000 gallons of salt or fresh water. The third and second versions go up even more. So, for a normal use, the first product is all you need.

This device will remove all unwanted floating substances from the water, like remaining algae, parasites and all kinds of bacteria that could sicken your fish.

Also, like I said above, it’s a huge pro that the Coralife works with both fresh water and saltwater systems. This means that you can use it for a very long period of time, without the need to upgrade.

However, there is a negative aspect about this product as well: it needs a little more knowledge to install, when compared to the others on the list.


2. AquaUltraviolet Advantage 2000+

This device is designed to work with small aquariums, usually, indoor fish tanks, that have smaller volumes of water. If you are a beginner fish keeper, with a small to medium sized tank, this device is a great choice for you.

The device is developed, to sterilize a tank in 3 to 5 days, depending on your tank’s size. Usually, you can leave it working even in the night, so it will finish the cleaning process quicker.

It was designed to get rid of all the algae (other protozoa just as well), bacteria and viruses from the water. It has a 15-watt motor, that is easily capable of completing the job in the set-out time stamp.

However, this motor isn’t enough to sterilize a bigger amount of water. Keep this in mind, and use it accordingly.

As a pro, it’s worth mentioning, that the AquaUltraviolet is also good for use in small water ponds outside. This way, even your small “lake”, will be free of the harmful bacteria and viruses, that can affect your water life.

The negative aspect about this device, is that you can’t really use it, if you plan to expand your tank. It will only work with smaller aquarium. So, if you set up a bigger tank in the future, you’ll need to look for another sterilizer that can work with bigger volumes of water.


3. AA Aquarium Green Killing Machine

This UV sterilizer is among the best on the market. It comes in one version alone, but that is more than enough, no matter how dirty your aquarium’s water is at a certain point.

A great aspect about this device, is the fact that the installation is very simple. You don’t need any tools to do the job, only 10 minutes, and the device will be ready for use.

This product was designed to work with aquariums of up to 50 gallons in volume. This means that even bigger fish tanks will pose no problem at sterilization. The device will pump the water at a rate of 220 Lt/hour. This is more than sufficient for an indoor fish tank.

Also, the package comes with a 3-year warranty, meaning that if something breaks during usage, you can send it back for free and they will mend it for you.

As long as negative aspects go, this one is liked by almost every user. It does its job really well, without any problems.


4. SunSun JUP –01 9W UV Sterilizer

If you own a bigger tank, than this device is for you. It manages to sterilize the water in aquariums of up to 75 gallons in volume.

It will clean the tank from all unwanted microorganisms and algae, that dirty your water. It’s simple and effective, but also compact and easy to install. Meaning, it won’t give you headaches to make it work.

To optimize the UV exposure, the SunSun comes with a mechanical filter sponge added into the device. This will capture the solid debris that floats around in the tank. This way, the UV sterilization process will be much more effective because it will work on water that is already filtered using a different method.

Also, this device works for both fresh and saltwater aquariums. So, you can use it in indoor fish tanks, as well as small fishponds, placed outside.

This device doesn’t really have any cons, because it works with small and large tanks, and it does the job perfectly. Also, if you take a look on the Amazon selling page, you won’t notice negative reviews, meaning that it does what it claims.


5. AquaTop UVCP – 13

This is the last product on our list, but that doesn’t mean it’s worse by any means. If you want a genuinely powerful water UV sterilizer, the AquaTop is a great choice. That’s because it can handle over 2,000 gallons of water.

In doesn’t matter if you have a saltwater tank, or a fresh water one, the AquaTop is good for both situations. It comes with a long (16ft) power cord, so you can use it outside easily, in a small fishpond, if you want to.

Also, it is very efficient at cleaning the water. It will get rid of all the algae in the tank, also the microorganisms that can cause diseases in the habitat.

The AquaTop has a built-in pump system, so you don’t have to set that up separately, like with other products that don’t include this part. The installation is simple and quick, easily done without any prior knowledge.

Now that you about the 5 best UV sterilizers on Amazon, we should know what the benefits are for using such a device.


Benefits of UV Sterilizer in Aquarium

The most important benefit that comes with using a UV sterilizer in conjunction with the standard water filter you already have, is the algae removal. It doesn’t matter what kind of aquarium you own; algae will begin to form in it.

If the fish tank is regularly exposed to light, the algae will grow very quickly. But in most cases, your fish will need light, to thrive in the tank. And on top of that, the accumulation of algae will dirty your water, giving it a dark green color.

So, what can you do? This is why a UV sterilizer is so important. It will get rid of all the algae in the tank, even if the habitat is constantly exposed to sunlight. The water will regain it’s crystal clean look, and the green muddy color will fade away.

There is another huge benefit that UV sterilizers come with. They destroy almost all the harmful bacteria and parasites that can appear in the water. Any of these substances could negatively impact your fish. Some bacteria can even go as far, to kill some of your fish. I bet you don’t want anything like that to happen.

The UV sterilizer will get rid of all these parasites, viruses and bacteria, leaving a clean and healthy environment, where your fish can thrive for a long time.

But how does a UV sterilizer really work? How does it get rid of all these harmful particles? Let’s see!

How UV Sterilizers Work?

Like its name suggests, the UV sterilizer will use ultraviolet light to clean the water. But how? UV light is split into multiple different ranges: UV-A, UV-B, UV-C or Vacuum UV. The UV-B range is the one that causes sunburn on humans.

But the UV-C light, is used by sterilizers to destroy harmful substances in the water. How? This UV range will break the molecular bonds between the DNA particles of bacteria and viruses. Because of this, the viruses and bacteria that are treated by a UV sterilizer, will die out, because they won’t be able to reproduce anymore.

UV light can kill many different bacteria and viruses, due to its properties. That’s why UV sterilizers are very effective at cleaning and sterilizing a tank that’s full of fish.

But maybe you’re asking yourself, how to install such a device in your tank? If you already picked a winner from the 5 items I listed above, it would be good to know how you can install it.

How to Install an Aquarium UV Sterilizer?

Installing a UV sterilizer, depends on the type of device you choose to buy. Since most of the items I listed above, come with a built-in pump system, I will tell you exactly how to install such a device in your tank.

This is an all-in-one device, that includes the following parts: an internal filter, a pump and the sterilizer itself. Usually, such a device is quite small, and it suits best smaller fish tanks, and small ponds.

In most cases, the installation consists in 2 steps:

  1. Put the sterilizer in the aquarium
  2. Connect it to the power supply

Yes, that’s all. From then on, the device will do its job by itself. However, depending on the item you bought, you should read through the user manual, to see if there are any special requirements to install the device.

In most cases, there isn’t much else to do about it, but it’s best to be sure you do everything by the book.

If you use a more complex sterilizer, you’ll need to connect the pump to the device, and plug it into the power source. The user manual will probably tell you even more about the installation, which can differ depending on the product at hand (only at those that are not all-in-one devices).

How to Choose a UV Sterilizer for a Fish Tank?

In case you didn’t choose a device yet, let’s see what you should look for, when you choose a sterilizer for you tank. This way, you’ll surely make the right decision.

First of all, the size of your tank is a definitive aspect you must look at, when choosing a UV Sterilizer. Why? Simply because different products, are designed for different aquariums.

As you can see from the 5 products I talked about above, there are some that works only with smaller tank, and other that work with both small and big aquariums. If you have a big fish tank, or you plan to expand to a bigger one, its best if you choose a device that can handle that much water from the beginning.

Another thing to look out for, is the type of sterilizer you want to buy. As I said previously, you can choose from all-in-one devices and those that come with a pump and filtration system separately.

For a beginner fish keeper, I suggest an all-in-one device, because it’s way simpler to install and maintain. However, if you’re an experienced fish enthusiast, you can go for a more complex item as well.

Something else to look out for, is the amount of water it can sterilize in a certain period of time. More exactly, you should know how the water flows through the sterilizer. This is important, because depending on these numbers, you can deduce how efficient the device will be, at cleaning your tank.

Of course, for this to work, you need exact numbers from the aquarium as well. This way, you can compare them, and choose upon a device that fits your needs.

If you know how to choose the best item for yourself, you should also know if UV light is harmful or not, for you water life. After all, you want to keep your fish healthy, right?

Is UV Light Safe for Fish?

Usually, UV light won’t do any damage to your fish. However, if the light exceeds the amount your fish would receive in the wild, it can become harmful to them.

This amount is different from one species to another. Before buying a UV sterilizer, you should do some research about the fish breeds you own. This way, you’ll know if they support or not a certain amount of UV light in the tank.

Luckily, most UV sterilizers, come with protection. The light bulb is placed inside a tube, where the water is sucked into by a pump. The light only shines in this tube, without going outside. This way, your fish are safe from receiving too much UV light.

But be careful when choosing your device. The ones I listed above are good choice, but there are others that don’t put too much interest on being safe to the habitat. Avoid such items.

Is UV Sterilizer Good for Killing Algae?

As a matter of fact, a UV sterilizer is among the best devices to get rid of the algae in your aquarium. Like I mentioned above, the UV range used by such device, decomposes the algae, thus removing it from the tank. A performant UV sterilizer can clean a tank from all the algae by itself.

However, if you want to do an easier job, it’s good to have some algae eaters in the tank. Fish that mainly consume algae, will help keeping the tank clean, and the sterilizer won’t be forced too much. Basically, this process is even more efficient, than using only a UV sterilizer.

Now, the only thing you should know, is how long a sterilizer should be working, to be able to clean the water:

How Long Should UV Light be on in Your Aquarium?

For start, longer the light is on, the more bacteria and algae will be erased from the tank. That is quite obvious actually, considering that longer the contact time, more water gets to be sterilized.

But maybe you’re thinking how long does it take for the light to sterilize the whole tank?

Usually, this depends on the tank’s size. The more the water, the more time it takes. However, this is not always true.

That’s because when you buy a more performant UV sterilizer, that has a bigger tube and more powerful light bulb, the water will be sterilized much quicker.

I mentioned above that the AquaUltraviolet will sterilize the water in 3 to 5 days from installation. This time period is similar with many other devices. The point is, when the water was sterilized, you should take the device out, and put it back later, when it’s needed.

This way, you can protect your fish from any harmful effects that the UV light might have on them.


Now, let’s do a quick recap of what we talked about in today’s article:

At first, I talked about the 5 best aquarium UV sterilizers used by lots of people. Any of them, can prove to be a great device for your tank. But to make the best choice, you should take consideration on multiple aspects, as I covered later in the article.

You must know the size of your fish tank, to be able to make a good decision on which device to buy. Also, you’ll need a device that works best for your needs: an all-in-one sterilizer or the more complex version.

I also talked about the process with which a sterilizer is cleaning the water. This can prove to be helpful information, when you choose the winner from the 5 items I talked about.

Installing the sterilizer is also an important step you must take to be able to use it. Most all-in-one devices are very simple to install, without the need of much technical knowledge. However, if you plan to buy a filter that comes with aa separate pump, you have to do everything like described in the user manual. That’s because most sterilizers of this type, have different installation processes.

UV light isn’t harmful to your fish in small amounts, as long as the quantity of UV light doesn’t surpass the one your fish would receive in their natural habitat.

Now, all that remains is for you to pick a winner from the 5 devices I mentioned above.

But before you do that, do some thorough research about your aquarium, and about the fish you own. This way, you’ll know for sure which item is best suited for your tank.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.

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