5 Best UV Sterilizer for Aquarium Of 2021

Last updated on December 24th, 2022 at 11:04 am

Aquarium UV sterilizer is an essential device for the proper management of saltwater and freshwater fish tanks. It replenishes the fishery’s filtration system to kill parasites, viruses, algae, and floating bacteria in the water. Another reason for the importance of sterilizer is its ability to control the spread of infections through water from a fish, coral, or vertebrate. Without these devices, harmful microorganisms can spread rapidly and destroy the entire population of a fish or pond.

Suppose you have ever had an issue with Green Water algae in your aquarium. In that case, you recognize how hard it is often to eliminate those pesky single-celled organisms. One of the only effective ways to stay free-floating algae in control is to use an ultraviolet sterilizer.

Keeping an aquarium clean is essential for the health of your fish. In poor water conditions, it’s easy for the disease to spread faster. Even the foremost experienced aquarists may encounter disease or remove fungus from the aquarium, leading to the loss of fish. They are designed to eradicate harmful microorganisms before they cause problems for your fish. 

This article will cover everything you would like to understand about the best UV sterilizer for aquariums. What are they? Do you need one? How does someone pick the proper one? Let’s take a glance at what the best UV sterilizers can do for your tank!

Top Best UV Sterilizer for Aquarium Of 2021

For professional quality UV sterilization that can clarify and sterilize water, I recommend SunSun JUP-01 9W UV Sterilizerdepending on the size and design of your current system.

For better water clarification in small and medium-sized tanks, the COODIA Green Water Killeris an inexpensive choice and is easy to set up and use.

The Coralife Turbo-Twist has a flexible design and provides excellent clarity for larger tanks, but it is much better if you need natural protection for fry.

1) SunSun JUP-01 9W UV Sterilizer Submersible Filter Pump

SunSun JUP-01 9W UV Sterilizer Submersible Filter Pump

Key Features:

  • Dimensions: 4 x 4 x 12 inches
  • Weight: 2 pounds
  • Color: Black
  • Flow rate: 210 gallons per hour

This SunSun JUP-01 9W UV Sterilizer Submersible Filter Pump is a good selection for large tanks and is suggested to aquariums up to 75 gallons in size. It features a built-in pump and is ready to hold inside your tank instead of connecting in-line to your water flow system.

The sterilizer is large and produces tons of suction, which may be problematic for reef tanks with fish familiar with living in calm waters. The 210-gallon per hour flow is exceptionally too high for tanks that are smaller than 75 gallons. You should also watch your water temperature in a tank of fewer than 55 gallons regularly. UV sterilizer bulbs emit heat and it will raise the water temperature to dangerous levels.

However, sterilization is highly effective because of the relatively large length and diameter of the chamber. The sterilizer is straightforward to put in and maybe hung vertically or horizontally, counting on the setup of your tank.

1. Needs no additional power due to excellent built-in water pump.
2. Sponge pre-filter reduces the water turbidity and increases performance.
3. A compact submersible sterilizer can be placed horizontally or vertically in your tank.
4. Change bulb yearly to maintain the optimum UV performance.
1. Difficult to install due to little information on the instructional manual.

2) COODIA Internal Green Water Killer Filter UV Pump

COODIA Internal Green Water Killer Filter

Key Features:

  • ASIN: B07V26V5MS
  • Dimensions: 11.65 x 5.59 x 3.31 inches
  • Weight: 1.59 Pounds
  • Color: Black
  • Flow rate: 190 Gallons per Hour

If you are finding an easy-to-use but very effective product to clean up to a 75-gallon tank, the best-selling COODIA Green Water Killer is a superb choice. It is the No.1 selling UV sterilizer on the market. Its advanced UV sterilizing technology, simple design, affordable price, and internal pump works stunningly. This 5W UV sterilizer is our top pick for 50-75 gallon-sized tanks.

The replaceable 5W bulb kills harmful microorganisms and free-floating algae. This UV sterilizer comes with strong suction cups so that it won’t subside and an adjustable outlet. So you’ll control the direction of the flow beginning of it.

Unlike other models, this sterilizer doesn’t require any extra plumbing. It is an in-unit sterilizer that goes directly into your tank and has an internal pump for pumping water through the bulb housing. Its small size and lack of external plumbing make it easy to cover behind an ornament or plant. The unit’s simple design and in-unit pump make it quick and straightforward to put in.

Replacement bulbs are readily available and comparatively affordable. This Green Water Killer is a fantastic UV sterilizer for medium-sized fish tanks. If you buy this unit, it’ll have your 50-gallon saltwater or freshwater tank sparkling clear and freed from algae in only a few days.

1. Green Water Killer can turn green water crystal clear in only 3-7 days.
2. Suitable for Saltwater and Freshwater.
3. The ceramics rotator is completely anti-corrosive.
4. A great function will generate bubbles in the water.
5. It provides full-spectrum light for plants.
1. Improper use can kill your favorite fishes in your tank.

3) Coralife Turbo 6X Twist UV Sterilizer

Coralife Turbo Twist UV Sterilizer, 6X

Key Features:

  • ASIN: B0064JHVOE
  • Dimensions: 16 x 9.25 x 3.25 inches
  • Weight: 5.6 Pounds
  • Color: Black
  • Flow rate: 240 Gallons per Hour

The Coralife Turbo 6X Twist UV Sterilizer is perhaps becoming the foremost widely available UV sterilizer. The best feature of this sterilizer is that it’s a twisted chamber that cuts down on the dimensions making this a compact unit even for its larger models. It still must be used with a Canister Filter or a Sump, but you will work with smaller spaces with it.  

It’s a singular twist flow design that controls the water stream more evenly through the sterilizer. The increasing exposure to ultraviolet and improves the treatment of unwanted algae and harmful microorganisms. They are often used with freshwater and saltwater aquariums.

Coralife bulb’s construction with quartz to allow maximum emission of ultraviolet energy to make it the best UV sterilizer for aquarium. The high-intensity output and spiral design significantly increase dwell time that making it a primary category sterilizer, which can satisfy most requirements for aquarium and fish keepers.

Overall, it is an honest all-around unit that’s easy to seek out in stores and straightforward to urge UV bulbs and replacement parts.

1. It comes with a 1-year warranty.
2. Easy to setup and comes with detailed instructions in the manual.
3. It can be mounted with a bracket or attached to your canister filtration system.
4. It can use in both freshwater and saltwater.
1. Price is relatively high compared to competitors.

4) Fluval UVC in-Line Clarifier 3W Low Energy UV Sterilizer

Fluval UVC in-Line Clarifier

Key Features:

  • ASIN: B08KSF2FT6
  • Dimensions: 2.6 x 6.3 x 5.12 inches
  • Weight: 1.1 Pounds
  • Color: Black
  • Flow rate: 225 Gallons per Hour

The Fluval UVC in-line sterilizer provides the best chemical-free and maintenance-free way to purify water. It destroys bacteria and algae suspended in the water column that contribute to cloudiness and green water, respectively. This often prevents the growth of cyanobacteria that destroy aquatic plants. This is beneficial and does not harm the bacteria that live on the surface. The unique capacitor design rotates the water up, down, and around the bulb to maximize contact time with harmful bacteria for effective clarification.

CCFL (Cold Cathode Fluorescent Light) technology lasts 30,000 hours (3 x lengths) longer than traditional UVC bulbs. This as the best filter for an aquarium can easily fit in the fish cabinet without cluttering the existing filtration system.

It quickly connects all bottle filter hose connections with an inner diameter of 5/8″ (or 16 mm), including all Flow 07 and 06 series filters. There is no need to move the existing filter system because it works in many directions. The design makes it energy efficient, saves 80% less electricity, and is less expensive to operate. This includes a 24 hour timer for mounting hardware and custom intermediate use. Algae are also often found in freshwater, saltwater, and algae fish stocks.

1. Great Ultraviolet germ and algae killer.
2. Consumes 80% less energy than competing sterilizers.
3. A product with excellent value for money.
4. The UV bulb has a warranty of 3.5 years.
1. Improper use can easily damage the product in no time.

5) Aqua Ultraviolet Advantage 15 Watt Aquarium UV Sterilizer

Aqua Ultraviolet Advantage

Key Features:

  • ASIN: B000NP6W1S
  • Dimensions: 1.5 x 3.3 x 7.2 inches
  • Weight: 1.4 Pounds
  • Color: Black
  • Flow rate: 240 Gallons per Hour

This decisive Aqua Ultraviolet Advantage is suitable for medium-sized tanks where an in-line UV sterilizer is preferred over a hanging sterilizer. This sterilizer design support flow rates of up to 240 gallons per hour. It can use to control the flow rate using your tank’s pump system and live time for complete sterilization. The sterilizer is suggested for tanks up to 75 gallons. 

The three-inch diameter unit is compact and lightweight; ensuring that all the water in the room is effectively exposed to ultraviolet light. The outer tube is constructed from heavy-duty PVC plastic to ensure durability.

Aqua Ultraviolet Sterilizers are very easy to install in your water flow system for barb-style input and output. However, it is worth noting that the unit does not come with mounting brackets or hoses. This aqua UV series is suitable for small ponds, aquariums, and water tubs. Its lightweight and slim unit design provides maximum UV performance. According to our instructions, performance is guaranteed when installed and operated correctly.

1. An in-line sterilizer is ideal for large freshwater tanks and outdoor aquariums.
2. Support water flow rate up to 240-gallon tank.
3. It can clean your water overnight in 3 to 5 days.
4. The manufacturer offers a 1-year warranty.
1. Separately purchase high quality and powerful pump

Advantages of Using UV Sterilizers in Aquarium

UV sterilizers are very effective when used as a preventative measure. In this category, UV sterilizers have several applications:

Algae and fungal control:

UV light counters algae and fungi in two ways. Firstly, control the diffusion of organic matter in the water. The algae and fungi in the water are also restricted. Second, ultraviolet water sterilizers kill spores and free-floating algae, spreading these nuisances and disrupting their growth.

Removal of cloudy water:

If your fish suffers from a prolonged cloudy water problem, it is best to use an ultraviolet light bulb for the tank. The sterilizer only kills the free-floating microorganisms present in the water flowing through it, so it is entirely safe for biological filter media and beneficial for nitrifying bacteria that live on the surface of the gravel.

Green water removal:

Green water is a highly recyclable, fast-growing single-celled alga that quickly spread in the aquarium. Using UV sterilizers is one of the best ways to control and remove this type of algae. For those who have fisheries that receive adequate sunlight or outdoor ponds, they are a practical necessity.

Parasite control: 

If the UV light bulb is adequately spreading, it can be eliminated almost all free-swimming parasites. When combined with the proper tank or pond maintenance, parasites can become incredibly difficult to keep up with. In the case of existing infections, UV contraceptives and water changes will quickly send the invading parasites along.


By removing organic matter in the water column (including foreign objects that may accidentally introduce into the water), UV light reduces the number of potential disease factors and components that impair water quality and clarity. It can also kill bacteria and viruses.

Efficiency Factors of an UV Sterilizer

Some major factors can influence the efficiency of chosen best UV sterilizer for aquarium:


104-110 degrees F is the optimum temperature for producing ultraviolet light. Cold temperatures will cause less UV production. Quart sleeves work by insulating the bulb from freezing, thus maintaining high UV production.

Bulb Age:

The ability to generate ultraviolet light reduces with the age of the bulb. As the bulb ages, it can lose up to 40% of its efficiency and reduce radiation. So, replacing a bulb every six months is a maintenance trick.

Contact Time:

The more UV light is exposed to the affected water; the more killing power is available there. It is affected by the flow rate. The contact time focuses mainly on the dictated flow rate.

Contact Power of the Bulb: 

The higher the wattage of the lamp, it will produce more UV light. The length of the lamp affects the contact time. A longer bulb will provide a longer contact time between UV light and water.

Flow Rate: 

Flow rate affects contact time. When the water flow rate is low, the contact time will give high efficiency. Different flow rates are required to control other organisms.

Turnover Time: 

It is time to get the total amount of fish to cross the aquarium. But this is a bit difficult to calculate because it can sterilize not all water.

Size and Type of Organism: 

Large organisms such as protozoa require high levels of UV. On the other hand, a small amount of ultraviolet radiation is inactive for a tiny organism such as bacteria. Apart from these, some types of bacteria are more resistant to ultraviolet radiation. But the good thing is that this ultraviolet light does not inhibit the beneficial bacteria.

Unit Size: 

A large tank requires an extensive UV system to cover the entire area. So, buy one, keeping in mind the size of the aquarium. If you believe a small UV system for a large-scale aquarium will not work effectively.

Water Turbulence: 

Clearwater helps for better penetration. The lower the turbulence of the water gives the higher penetration of ultraviolet light. If the water is mainly cloudy, you can reduce the flow rate until it clears again. It should also note that UV penetration works better in the freshwater tank than in the saltwater tank.

Frequently Ask Questions

Do I need a UV sterilizer? 

UV sterilization of fish can be very helpful in maintaining a healthy environment. People struggling with disease outbreaks or moss flowers may consider buying one to help with the problem.

Is a UV sterilizer worth it? 

If set up correctly, the UV sterilizer will kill the pests you want to go to. Beneficial bacteria will not be killed if they do not run in water. You don’t have to worry about your fish; they may be stressed with the device at first but get used to it.

How to choose the best UV sterilizer for aquariums? 

There are many UV sterilizers out there, so it can be a little confusing when choosing the one you need. The main factors to consider are the power of the pump and the power of the lamp. You need to consider the size of your tank and the types of germs you want to kill to determine the right mix.

How do I maintain my UV sterilizer? 

Maintenance is effortless. It’s a matter of cleaning so that you can operate it as efficiently as a filter. This includes cleaning the crystal sleeve and pump whenever you can replace failed parts such as the bulb.


Investing in the best UV sterilizer for aquariums for your fish pond is a great way to reduce algae blooms, prevent the spread of disease, and improve the health of fish. These devices are very effective for water clarification but can achieve natural sterilization if the selected models are set up and maintained properly. Sterilizers for a long time save you money by keeping your tank healthy, which means you do not have to change your freshwater or saltwater. They are easy to install and easy to care for and are recommended for both beginners and experienced fish keepers.

4 thoughts on “5 Best UV Sterilizer for Aquarium Of 2021”

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