7 Best Aquarium UV Sterilizers in 2023 – Review & Buyer’s Guide

If your tank has an algae problem, a UV sterilizer is one of the easiest ways to deal with it for good. These sterilizers pump water in front of an ultraviolet light to kill algae and bacteria. They often attach to tank filtration systems, although there are several different types of setups available. These sterilizers are ideal for getting rid of harmful bacteria without harming your fish and keeping algae under control. We hope these reviews of some of our favorite products help you find the right gear for your tank.

A Glance at Our Top Picks (2023 Update)

The 7 Best Aquarium UV Sterilizers

If you’ve already got a good setup and you just need to add in some UV, the AA Aquarium Green Killing Machine is the best overall choice for you. This sterilizer system is easy to install and doesn’t require any special tools to setup—you just attach the suction cup and plug it in. It is safe for freshwater and saltwater tanks and will run smoothly and quietly, clearing out algae and harmful bacteria quickly. Within days you’ll see a big difference in your tank’s algae problem. One nice feature of this sterilizer is that it puts water through a zig-zag course in front of the UV light, maximizing the time that it spends being cleaned.

Although this sterilizer has a water pump, it isn’t a filtration system. It is an easy add-on if you’ve already got a good UV-free system, but it will need its own plug-in. If you are setting up a whole tank system, getting a built-in sterilizer filtration system may be better. This sterilizer also has opaque housing that makes it impossible to see the UV light when running. This is nice in some ways, but it does mean that you have to check occasionally to make sure the lightbulb isn’t burned out.

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The Hang-ON Aquarium UV sterilizer from SunSun is a great choice for small fish tank owners. It’s perfect for tanks of up to 50 gallons, with two sizes of filter available, and it combines a filtration system and a UV sterilizer. Its three-stage filtration system helps keep your tank clean with adjustable water flow and a built-in skimmer. Two adjustable filter media baskets let you customize the filter media, and it is safe for freshwater and saltwater tanks. It runs quietly and is energy-efficient compared to many others. However, one drawback of this tank style is that the UV bulb can be difficult to find when a replacement is needed.

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The SunSun HW-304B Aquarium UV Sterilizer is the perfect choice if you need an upgrade from a basic filtration system. This highly customizable system is well worth the price because of its powerful performance and high level of customization. It includes four filter media trays that can be customized with many different types of media to provide the filtration that your fish needs, and it is suitable for fish tanks of up to 150 gallons. There are various sizes of hoses and connectors that allow you to customize your tank’s setup and tweak it to fit your needs. The built-in UV sterilizer has a powerful bulb and a separate on/off switch so you can decide whether to leave it on permanently or just use it as needed. This system is ideal for many, but it isn’t a beginner system—the canister style filter is more difficult to set up than other styles and takes up a lot of space, so it’s best suited for fish keepers with some experience.

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The Coralife BioCube Mini Ultraviolet Sterilizer is another good choice for a sterilizer. It is designed to work with BioCube small fish tanks and hooks into the existing filtration system, however, it also includes a universal adaptor for small fish tanks. Because this product doesn’t include a pump, it doesn’t have a specific recommended tank size although it is designed for smaller tanks. It is fairly easy to install in BioCube tanks, although some reviewers found the universal adaptor confusing. The adaptor has a small 5-watt bulb that sterilizes water, killing harmful algae and bacteria as your tank filter works. This sterilizer isn’t ideal for all tanks, but if you have a small fish tank or a BioCube tank that is compatible with the sterilizer it may be the option for you.

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An excellent option for a combined filter/sterilizer system is the Aquatop Hang-On Back Aquarium UV Sterilizer. This system contains a combined filter/sterilizer that is easy to set up and needs minimal installation help. It’s great for marine or freshwater tanks and comes in three sizes ranging from 15- to 40-gallon capacity. The filter system has a self-adjusting skimmer and an adjustable flow of 64–128 gallons/hour filtering capacity. The sterilizer is integrated into the plumbing system, so you don’t need any extra installation, but it does have a separate cord, meaning that the system requires two outlets to function properly.

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The AA Aquarium Green Killing Machine Clip-On Filter is an alternative to Green Killing Machine’s larger sterilizer meant for smaller tanks, with a completely different design. This clip-on filter sterilizes water with a 3-watt bulb that lasts for up to 9 months of continuous use, killing algae and bacteria continually. It has a low-flow system that allows it to be quieter and more energy efficient than many integrated filter systems, cleaning the tank within hours or days. It installs in minutes with no special installation setup needed. This UV filter is separate from the filtration system, so some users might prefer to buy an integrated system rather than having a UV filter and a standard filtration system.

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The Coospider Sun JUP-01 is a fully submersible aquarium filter that is perfect for getting algae out of water while also giving a little boost to your filtration system. The JUP-01 has supplementary filtration and oxygenation filters, but because of its fully submerged design it isn’t suitable as the main filter in your aquarium. This filter needs to be fully submerged at all times while in use—running the machine outside of the water causes damage to its motor. One nice feature of this machine is that it’s easy to clean and maintain the interior, with an easy-to-open housing. It comes with a spare UV bulb to help the filter last longer before you need to track down a replacement bulb.

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Buyer’s Guide: How to Find the Best Aquarium UV Sterilizers

There are lots of different factors to consider when buying a sterilizer. There are many types of sterilizer setups available, including in-line, built-in, and separate systems.

In-Line

In-line systems are installed into an existing filter. They are great if you already have a filter system set up and you’re willing to do some work to add in a sterilizer filter. They tend to work better on larger tanks because they are usually designed to work with external filters. They are also some of the most powerful systems available, so if your tank already has a parasite or algae problem they work well. The biggest drawback is that they require more work to install and they don’t work on all filtration systems. They also usually need a separate power source.

Bottom Line: In-line filters are the most powerful option, but they are best with external filters and take some work to set up.

Built-In

Some filtration systems come with a UV sterilizer built into them. This is a great option if you’re just picking out a tank and setting up, and you don’t already have a filter. These are often easy to use and might have a separate on/off switch. It’s important to find a filter that works well, and UV lights are a nice bonus. They also usually don’t need a separate outlet.

Bottom Line: If you’re setting up a new tank, consider getting a filter with a built-in UV light for ease of use and no extra outlet needed.

Separate

If your setup has a HOB filter or another system that doesn’t work with an in-line filter—or if you’d rather not install it—you can also buy a UV sterilizer that has its own pump. These are a little less efficient because they can’t utilize your filter’s existing pumps, but they are easy to pop in and out of the tank as needed.

Bottom Line: Separate filters take up a little bit of space and they require their own built-in pump, but they are easy to use if you don’t want to mess with your current filter system.

Conclusion

There isn’t one setup that works better than anything else, but that doesn’t mean there aren’t some great filters. We found the AA Aquarium Green Killing Machine UV Sterilizer to be the best overall because of its high power and ease of use. Our favorite value option was the SunSun Hang-On Aquarium UV Sterilizer Filter, which works great for tanks of up to 50 gallons. And if you need something a little more powerful, the SunSun HW-304B Aquarium UV Sterilizer was our favorite premium option, packing a lot of value into its canister-style sterilizer.

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Featured Image Credit: Krys Amon, Unsplash