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Owning a pond is an incredibly rewarding experience and can make any garden look stunning. However, to keep your pond looking its best, a fair amount of maintenance is involved.
Ponds, particularly outdoor koi ponds, are susceptible to algae outbreaks, bacteria, and parasites. This can have a serious effect on the appearance of your pond and the health of your fish.
Why Consider a UV Sterilizer?
A UV sterilizer can help with these potential risks by creating a clean and sterile environment for your fish. If you have an algae problem, it’s good to get one. The way UV pond sterilizers work is by using extremely powerful ultraviolet light to help eliminate algae blooms, bacteria, parasites, and any other nasties that might be lingering in your water.
For any pond owner, a UV sterilizer is a piece of equipment you definitely want to have around. It can be a little confusing when it comes to picking a good UV sterilizer for your pond, especially if you’ve never used one before.
To help you figure out the best pond UV sterilizer, I’ve reviewed an array of units and taken a close look at their advantages and disadvantages in this UV pond sterilizer review.
After considering all the options our top picks were…
Review Summary
The unit is 36 watts and can handle up to 8800 gallons, so it should be plenty for medium-sized ponds.
Best All-Rounder: Jebao PU-36 Pond Clarifier
Out of all the units I’ve reviewed, this UV pond clarifier is my overall recommendation for most ponds.
For the majority of ponds, the Jebao UV pond clarifier is a good option. It can handle up 8800 gallons and has a wattage of 36. When installed correctly, this UV clarifier can remove algae from your water in just 3 to 5 days. It’s also efficient at eradicating other pathogens in your pond water
SunSun JUP-01 9W UV Sterilizer
This UV light unit is effective at eradicating bacteria, algae, and parasites from your pond water. It also effectively controls bad odors, which is ideal if you have a particularly bad smell emitting from your koi pond.
Best on a Budget: SunSun JUP-01 9W UV Sterilizer
This unit is a great choice for pond owners on a budget due to its affordability.
If your pond needs an inexpensive UV unit, then you can’t go wrong with this one from SunSun.
It has a water flow rate of 210 gph and a wattage of 9. The device is efficient at eliminating algae, bacteria, bad odors, and parasites without burning a hole in your wallet.
The unit performs very well and takes care of any algae, parasites, and pathogens in your water. The UV light bulb that comes with the device is very long-lasting and is effective for up to a year, so it shouldn’t need to be replaced very frequently.
Editor’s Choice: OXYFUL 24 W UV Pond Unit
My personal favorite UV device for a pond. It’s a little pricey but is extremely high quality.
Suitable for ponds over 11, 000 gallons, the OXYFUL 24-watt UV light unit quickly kills any pathogens in your water. It does an excellent job at clearing up algae, parasites, etc, from your pond water and making sure your fish are happy and healthy. The UV bulb can last for up to a year, which shows how durable the device is.
To find the ideal pond uv sterilizer, you must be familiar with what qualities to look for. Let’s go through different features that you should look out for.
What Wattage Should Your UV Unit Have?
The capacity of your pond comes into play when choosing a UV device with an appropriate wattage. Most UV pond sterilizers are available from 5 watts to 140 watts. Obviously, the bigger your pond, the higher watts you need to avoid algae problems.
TIP
In general, ponds that hold 500 gallons or less only need 5 to 8 watts. If your 500-gallon pond gets a lot of sun, has lots of plants, and a high amount of fish, then you might need a 10-watt to 20-watt UV sterilizer.
6,000-gallon ponds need a more powerful UV device, with around 40 to 45 watts being sufficient. If a pond this size isn’t shaded and holds a lot of fish and plants, then over 80 watts is advised.
Flow Rate and Turnover Rate
To effectively kill algae and bacteria, your UV unit needs to have a suitable flow rate. The flow rate of your unit is normally measured in gallons per hour (gph) or liters per hour (lph).
Higher flow rates are usually good for eliminating green water and certain types of bacteria, but a slower flow rate is better for ridding your pond of parasites. For most standard ponds, you should aim for a unit that has a turnover rate of 2 every 24 hours.
How Many Gallons Does Your Pond Hold?
If you’re not sure how many gallons your pond holds, then simply multiply the length of it by the width by the average depth to get the total cubic feet. Multiply the total cubic feet by 7.5 to calculate the number of gallons your pond is.
For example, if your rectangular pond is 5 ft in length, 4ft in width, and has an average depth of 6 ft, then the total cubic feet is 120. When you multiply the cubic feet by 7.5, you get 900. This is the total number of gallons your pond holds.
UV Sterilizer Versus UV Clarifier – Which is Better?
UV sterilizers and UV clarifiers are pretty easy to mix up, but there are a few vital differences between the two types of pond equipment. But they have the same purpose which is to deal with algae problems.
UV sterilizers and UV clarifiers are pretty easy to mix up…
UV Pond Clarifiers
While both units use powerful UV lights to kill parasites, bacteria, and algae, UV clarifiers typically have a lower wattage and a higher water flow rate. Like I mentioned earlier, slower flow rates are better for eliminating certain bacteria and parasites as they expose the pathogens to ultraviolet light for longer.
UV clarifiers can kill single-celled suspended algae but can’t eliminate string algae.
Parasites like ich and costia need a longer exposure time to effectively damage them, so a UV clarifier might not be successful for treating these illnesses.
I’ve written on better solutions on how to treat ich in goldfish if that’s what you’re in the market for.
When to use UV sterilizers and UV clarifiers
If you simply want to get rid of unsightly green water from your pond, then a UV clarifier is sufficient. However, if you want to provide your pond with a more sterile environment and want to prevent harmful bacteria and viruses, then UV sterilizers are a better option.
Will the UV Light Kill Beneficial Bacteria Too?
Since ultraviolet light is efficient at killing harmful bacteria, you might have wondered whether it can also eradicate beneficial bacteria too. Good bacteria is needed in any pond to help with the nitrogen cycle.
There is a bit of controversy involving UV devices and their effect on bacteria. For this reason, some pond owners use a UV sterilizer or UV clarifier with low wattage.
While UV light can kill beneficial bacteria, it is not enough to negatively impact your pond…
While UV light can kill beneficial bacteria, it is not enough to negatively impact your pond. Most good bacteria colonize on filter media, rocks, plants, etc, and UV devices only kill bacteria in the water.
However, it’s advised to let your pond fully cycle first before you install a UV clarifier or sterilizer to be on the safe side.
Tips and Safety When Using UV Units
UV clarifiers and sterilizers have very delicate bulbs and glass sleeves, so be careful when you’re assembling the unit or replacing a UV bulb. When putting replacement bulbs the connections need to be secure, but try not to force it as this can cause breakage.
NOTE
Additionally, when handling the UV bulb, make sure you don’t use bare hands. The natural oils present on your skin can affect the longevity of the UV bulb as well as cause it to overheat.
As UV bulbs emit harmful ultraviolet light, it’s crucial that you never look directly at the bulb when it is unshielded. If you need to check the light, only do so through the opaque window on the outer casing,
How to Install UV Light
When installing a sterilizer or clarifier, place either one in an area that won’t be easily flooded. Although these types of equipment are waterproof, they should not be submerged.
I recommend positioning the unit on a flat surface that’s dry, such as the lid of a canister filter. Make sure you connect the equipment to a GFI circuit or outlet to prevent electrical shocks.
UV Sterilizers Reviews
Now that you’ve gotten all the information you need to know about UV devices, you’re probably wondering what the best pond UV sterilizer is. To help you save time and research, here are some of my top recommendations. Hopefully, these pond UV sterilizer reviews will help you choose the best UV unit for your pond!
The unit is 36 watts and can handle up to 8800 gallons, so it should be plenty for medium-sized ponds.
Best All-Rounder: Jebao PU-36 Pond Clarifier
This UV pond clarifier is my overall recommendation for most ponds as it’s effective and not too costly.
Easy Installation
Installing this UV pond clarifier is fairly easy. It’s best to install this uv clarifier after your pond filter, but if you need to use it before the pond filter, make sure you use plenty of pre-filtration. This will help prevent the quartz glass sleeve from breaking due to debris in your water.
As long as you install the unit before your pond filter, it claims to eliminate algae or green water in as little as 3 to 5 days, so it shouldn’t be too long before your pond water is crystal clear again. The unit is also effective at destroying bacteria, viruses, fungi, and parasites.
The UV bulb is fairly long-lasting and only needs to be replaced after 6 to 12 months of continuous operation for optimal performance.
One major drawback of this UV clarifier is its durability. The unit is not made from the most high quality material, which can cause it to break prematurely or leak frequently.
Specs
- Size: 16 x 9 x 5 inches
- Weight: 5.09lbs
- Capacity: 8800 gallons
- Wattage: 36 W Full Specs
Pros
- Simple to install
- Quickly removes algae
- Long-lasting light bulb
Cons
- Not as durable as some other UV pond sterilizers
SunSun JUP-01 9W UV Sterilizer
This UV light unit is effective at eradicating bacteria, algae, and parasites from your pond water. It also effectively controls bad odors, which is ideal if you have a particularly bad smell emitting from your koi pond.
Best on a Budget: SunSun JUP-01 9W UV Sterilizer
If you’re looking for a good-quality UV unit that doesn’t break the bank, then this one from SunSun is a great choice for smaller ponds. It’s 9 watts and has a water flow rate of 210 gph.
The device is compact and comes ready to install. No extra tubing or a circulation pump is needed for setup, which makes it easy to get up and run.
This UV light unit is effective at eradicating bacteria, algae, and parasites from your pond water…
This UV light unit is effective at eradicating bacteria, algae, and parasites from your pond water. It also effectively controls bad odors, which is ideal if you have a particularly bad smell emitting from your koi pond.
The unit can be placed vertically or horizontally. It has a built-in pump and includes a UV ballast, UV-C lamp, mechanical pre-filter sponge, and mounting brackets with suction cups.
However, the design of this device can make it difficult to clean and maintain. Additionally, the unit can break or stop working prematurely as it’s not very durable.
Specs
- Size: 4” x 4” x 12”
- Weight: 2 lbs
- Water Flow Rate: 210 gph
- Wattage: 9 W
Pros
- Effectively removes algae and other pathogens
- Easy to install
- Compact design
Cons
- Can be difficult to clean or maintain
- Not very durable
The unit performs very well and takes care of any algae, parasites, and pathogens in your water. The UV light bulb that comes with the device is very long-lasting and is effective for up to a year.
Editor’s Choice: OXYFUL 24 W UV Pond Unit
Suitable for indoor and outdoor use, the OXYFUL UV pond unit is a fantastic choice for large ponds. It’s 24 watts and has a fluid rate of 1,320 gph, which makes it suitable for ponds over 11, 000 gallons.
The unit performs very well and takes care of any algae, parasites, and pathogens in your water…
The unit performs very well and takes care of any algae, parasites, and pathogens in your water. The UV light bulb that comes with the device is very long-lasting and is effective for up to a year, so it shouldn’t need to be replaced very frequently.
Easy Installation
Installing the device isn’t too complicated. It can be placed vertically or horizontally, but is best installed after your filter.
The reason why I prefer this UV pond unit over the others I’ve reviewed is due to its effectiveness. It quickly clears up your pond water and is great at keeping your pond free of any pathogens.
However, the device can struggle with extremely large ponds. Despite claiming to be adequate for ponds over 11, 000 gallons, the unit isn’t always effective at sterilizing ponds this big.
Specs
- Size: 21.5” x 6” x 5”
- Weight: 7.5 lbs
- Fluid Rate: 1, 320 gph
- Wattage: 24 W
Pros
- Quickly removes pathogens
- Easy to install
- Long-lasting UV bulb
Cons
- Not always effective at sterilizing large ponds
ThePondGuy UltraUV Pond Clarifier 18W
This 18-watt UV light device can be used with pumps up to 1,250 GPH, so it’s adequate for ponds up to 2000 gallons. This equipment performs fairly well and adequately removes algae, parasites, and other pathogens from your pond water.
ThePondGuy UltraUV Pond Clarifier 18W
This 18-watt UV light device can be used with pumps up to 1,250 GPH, so it’s adequate for ponds up to 2000 gallons. For the most part, the equipment performs fairly well and adequately removes algae, parasites, and other pathogens from your pond water.
The device isn’t too difficult to install and comes with universal fittings. The unit has a 5 year warranty.
My main issue with this unit is the durability of the UV light. It doesn’t have the longest lifespan and can break down after a few months of use. In addition to this, the device works best for smaller ponds. It can struggle to sterilize and remove algae from medium-sized or large ponds.
Specs
- Size: 14” in length
- Weight: 5.2 lbs (with packaging)
- Water Flow Rate: 1250 gph
- Wattage: 18 W
Pros
- Universal tubing fitting
- Efficient UV water exposure
- 5 year warranty
Cons
- UV light bulb can have short lifespan
- Can struggle to sterilize and remove algae in medium/large ponds
Coralife Turbo Twist 12x UV Pond Device
With a wattage of 36, the Coralife Turbo Twist 12x UV unit is suitable for medium-sized ponds. Due to its twist-flow design, it provides your pond water with ample exposure to ultraviolet light.
Coralife Turbo Twist 12x UV Pond Device
With a wattage of 36, the Coralife Turbo Twist 12x UV unit is suitable for medium-sized ponds. Due to its twist-flow design, it provides your pond water with ample exposure to ultraviolet light.
features an indicator light that notifies you when it is actively sterilizing…
The device features an indicator light that notifies you when it is actively sterilizing. It also comes with mounting brackets for hang on or in-line applications, which is handy.
The device is available in smaller sizes, but I recommend using the 12x variety for ponds. This makes sure any algae or pathogens in your pond water are dealt with promptly and efficiently.
The biggest downfall of this Coralife equipment is its durability. In general, the device has a short lifespan and is prone to leaking and rusting. In addition to this, the bracket included with the device is poor quality and can snap easily.
Specs
- Size: 20.9” x 3.9” x 5.6”
- Weight: 7.25 lbs
- Fluid Rate: Unknown
- Wattage: 36 W
Pros
- Unique design provides your pond water with ample UV exposure
- Indicator light lets you know when the unit is operating
- Comes with mounting brackets
Cons
- Short lifespan
- Prone to rusting and breaking
- Mounting brackets are not very durable
Conclusion
After considering all the options our top picks were…
Best All-Rounder
After looking at a variety of products, I think the best UV unit is the Jebao PU-36. It’s 36 watts and has a water rate of 4,400 gph. It promptly and efficiently removes algae and other pathogens from your water.
The feature I like the most about this device is just how quickly it gets to work. When installed correctly, any algae blooms in your water is taken care of within 3 to 5 days. This means you don’t have to wait very long for crystal clear water.
The only downside with the unit is its durability. Unfortunately, the material of these UV pond clarifiers is not the best quality. This can cause the equipment to leak or break easily. However, on the plus side, the bulb included with the device can last up to 6 to 12 months, which is quite a long time!
Other Options
If the Jebao sterilizer doesn’t appeal to you, then two other best UV pond units are the SunSun JUP-01 9W UV Sterilizer and OXYFUL 24 W UV Pond Unit.
Best on a Budget
The former is a fantastic option if you’re on a budget. It effectively rids your pond water of algae and other pathogens. It’s very easy to install as it comes with a built-in pump, but it can be hard to clean due to its design. Additionally, the device can wear out quickly.
Editor’s Choice
OXYFUL’s UV pond device is a little pricey, but is incredibly effective at sterilizing your pond water. It easily removes algae, parasites, bad odors, etc, from your pond water. The UV bulb that comes with the equipment is also very long-lasting. Unfortunately, the device can struggle to sterilize the water of extremely large ponds, despite claiming to be suitable for ponds over 11, 000 gallons.
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Thanks for reading! I hope that these pond UV sterilizer reviews helped you decide. For more pond accessories, check elsewhere on my site.
