When the water in your Koi pond gets green, you know that is the time to get a new UV sterilizer. The exceeded food causes the growth of algae, bacteria, parasites, viruses and other microorganisms, making the water less clear and full of bad odors. A UV light can clean the water up, keeping a healthy environment for you Koi fishes.
Here are my top picks for the best UV light for koi pond:
Here are the best uv lights for koi pond you can buy in 2021:
- Best Overall: Jebao 36W Aquarium Koi Fish Pond UV Light Sterilizer
- Easy To Install: Coralife Turbo-Twist UV Sterilizers
- Best For Smaller Ponds: Sun 13W UV Sterilizer
- Best For Big-Sized Ponds: Jebao STU Stainless Steel 75W UVC Clarifier
- Best For Green Algae Control: TetraPond GreenFree UV Clarifier
|Best UV Light For Koi Pond: Top 5 Picks|
|Jebao 36W Aquarium Koi Fish Pond UV Light Sterilizer||Read Our Review|
Easy To Install
|Coralife Turbo-Twist UV Sterilizers||Read Our Review|
Best For Smaller Ponds
|Sun 13W UV Sterilizer||Read Our Review|
Best For Big-Sized Ponds
|Jebao STU Stainless Steel 75W UVC Clarifier||Read Our Review|
Best For Green Algae Control
|TetraPond GreenFree UV Clarifier||Read Our Review|
Best Overall: Jebao 36W Aquarium Koi Fish Pond UV Light Sterilizer
- Effectively removes Algae, Bacteria, and Viruses
- For ponds up to 8,000 gallons
- Easy to install & easy to use
- For external use only
Jebao 36W is the best UV Light Sterilizer for medium ponds. It features a 36W UV lamp to effectively remove algae, bacteria, and viruses, keeping the pond clean for healthy koi fishes. The suction power is about 4,400 Gallons per Hour; the sterilizer is recommended for up to 8,000-gallon tank.
Besides, Jebao 36W is pretty easy to install and use. It is not so big and easy to disassemble, so it makes maintenance very easy. For the best performance, you should replace the bulb once a year.
Notice that Jebao 36W is only for external use; do not place it in the water, instead, install it in-line after a water filter.
|Jebao 36W Aquarium Koi Fish Pond UV Light Sterilizer Specifications|
20 x 13 x 4 inches
36W UV lamp
Up to 8,000-gallon tank
Jebao 36W removes algae, bacteria, and viruses effectively, for medium fish tank.
Easy To Install: Coralife Turbo-Twist UV Sterilizers
- Effectively removes algae, parasites, and bacteria
- Twist-flow design & Indicator light
- Can be hung on or in-line installed
- Works with both freshwater & saltwater
- Low suction power
Coralife Turbo-Twist is ideal for Koi newbies. You won’t want an over-complicated UV Sterilizer; Instead, you’ll want an easy to install, easy to use, and easy to maintain UV Sterilizer, which Coralife Turbo-Twist meets all.
Coralife Turbo-Twist has a twist-flow design which helps increase the exposure of water to UV light, maximizing the clean effectiveness. It features an indicator light, which helps you know whether the sterilizer is on. You can easily hang Coralife Turbo-Twist or in-line install the sterilizer. And it works with both freshwater and saltwater.
The main drawback of Coralife Turbo-Twist is the suction power, which may be considered low. It is recommended for up to 250 gallons of water.
|Coralife Turbo-Twist UV Sterilizers Specifications|
16 x 9.2 x 3.2 inches
Twist-flow design & Indicator light
Up to 250 gallons
Coralife Turbo-Twist is an easy to install & use UV sterilizer for small tank.
Best For Smaller Ponds: Sun 13W UV Sterilizer
- Effectively removes algae & microorganisms
- Compact, lightweight and versatile
- Clean up to 150 gallon tank
- Recommend for small tanks, 40-75 gallons
Sun 13W UV Sterilizer is my pick for smaller koi ponds. It has low power - 13W for the UV light & 8W for the water pump, but is enough for a 150-gallon tank. However, it is recommended for just 40-75 gallons of water. If the tank exceeds this capacity, it may take longer to clean the tank.
Overall, Sun 13W UV Sterilizer is compact, lightweight, and versatile. It is very easy to install and use. It cleans algae and microorganisms effectively, keeping your pond from green water. Sun 13W UV Sterilizer is also a good choice for beginners.
|Sun 13W UV Sterilizer Specifications|
3 x 2. 5 x 13. 5 inches
13W UV light
8W water pump
40-75 gallon tank
Sun 13W UV Sterilizer is compact, lightweight, and versatile, ideal for smaller Koi ponds.
Best For Big-Sized Ponds: Jebao STU Stainless Steel 75W UVC Clarifier
- Effectively removes algae, parasites, and bacteria
- Easily disassemble for maintenance
- Reflective stainless steel barrel for better UV efficiency
- Clean up to 9,000 gallons
- High price and bulky
Jebao STU is a high-power UV sterilizer, both the UV light and water pump. It is made of stainless steel for great durability. Inside of the barrel is electrolytically polished for better reflecting effect. So, Jebao STU has an impressive UV efficiency, effectively removing all types of algae, parasites, and bacterias.
Jebao STU can clean up to 9,000 gallons, ideal for big-sized ponds. Moreover, parts of Jebao STU is easily disassembled for clean and maintenance. However, Jebao STU is 10lb heavy and quite bulky. It has a quite high price as well.
|Jebao STU Stainless Steel 75W UVC Clarifier Specifications|
40 x 10 x 5 inches
Reflective stainless steel
Up to 9,000 gallons
Jebao STU is a high-power UV sterilizer, ideal for big-sized ponds.
Best For Green Algae Control: TetraPond GreenFree UV Clarifier
- Effectively removes parasites & bacteria, especially heavy algae bloom
- For ponds up to 4400-gallons
- Compact and lightweight
- Reflective stainless steel insert for better UV exposure
- High price
TetraPond GreenFree UV Clarifier has a reflective stainless steel insert for better UV exposure. It is great at removing parasites & bacteria, especially heavy algae bloom.
TetraPond GreenFree is not an overly powerful sterilizer like Jebao STU. In fact, it is quite compact and lightweight, only 1.2 pounds. Its capacity is about 4,400 gallons of water. So if you want a UV sterilizer with great UV efficiency, but not as big as Jebao STU, TetraPond GreenFree UV Clarifier is a great choice. However, in terms of price, TetraPond GreenFree UV Clarifier is not much less than Jebao STU.
|TetraPond GreenFree UV Clarifier Specifications|
4.1 x 15.2 x 9 inches
Reflective stainless steel insert
Up to 4400-gallons
TetraPond GreenFree UV Clarifier is ideal for green algae control in small to medium ponds.
How To Choose The Best UV Lights For Koi Pond?
- Choosing a UV light is pretty simple. You’ll want to know two important specs: the pump’s capacity and the UV light wattages. The pump should support the capacity of your pond. Every UV light has a recommendation on the pond size in its description, you'll need to read this through. You can evaluate your pond size by this simple calculation: Length (ft) x Width (ft) x Depth (ft) x 7.5 = Gallons.
- The wattage of the UV light determines how much water it can clean (per hour). For a small pond, you'll just about 10 - 20 W. For a medium pond, you'll need less than 50W. For a larger pond, you may need higher wattage.
- Other things you also might want to put into consideration are the size of the UV light, its weight, or its safety features.
Which Brands Make The Best UV Lights For Koi Pond?
- Jebao is a Chinese manufacturer of fish tank equipment, headquartered in Zhongshan. It was founded in 1998; up to present, it has built its worldwide reputation on fountain pumps, lights, aquarium accessories, and UV sterilizers. Their products are famous for high energy efficiency, which means they will save you a lot of the electricity bills and help protect the environment. Jebao also focuses on quality control and safety features, they have met a bunch of international certifications, such as GS, UL, CUL, BS, SAA.
- Not only in China but Jebao is also now famous across the world, the US, Canada, Germany, Singapore, and the UK is its main export markets. Jebao is the brand you can trust.
- Coralife is a sub-brand of Central Garden & Pet, an American traditional company in the garden & pet industry. It was founded in 1980 and has built its brand on a wide range of garden and pet products. They have a strong retail network across the globe, ensuring great customer services for each customer. They are famous for innovation and high-quality products with about $2 billion in annual sales.
- When it comes to fish pond products, Coralife has LEDs, Light fixtures, Protein Skimmers, UV sterilizers, Chillers, Filtrations, Power managements, Digital thermometers, and other accessories. If you are finding some tools for your fish pond, Coralife is a to-go brand.
- As you can see from the name, Tetra-fish focuses on products for fishes and ponds. They have a very long history, since 1951, and now is the biggest manufacturer of aquarium fish food. Besides, they provide a very wide range of products for fishes and ponds.
- Their products are among the best you can find in the market, both quality, appearance, and features. Coming with a very high-quality product is a higher price. Tetra-fish's UV sterilizers cost a little more than other products; however, it is really worth it.
Why do I need a UV sterilizer?
When the water in your koi pond gets green, you know that is the time to get a new UV sterilizer. The water in a fish pond may get polluted by algae, bacteria, parasites, viruses and other microorganisms, making the fishes die and causing unpleasant smells. A UV sterilizer can clean them up, keeping the water crystal clear, both freshwater & saltwater.
How does UV sterilization work?
Each UV sterilizer has a built-in UV light. This light destroys chemical bonds and messes up the DNA/protein structure, making microorganisms death. These microorganisms include bacteria, parasites, viruses, and even algae. When the water is pumped into the barrel, the UV light will get their work done, keeping the water clean.
How long does it take for UV to clear green water?
From my experience, if you install a new UV light for an old green-water pond, it may take five days to clean the water up. The water then will be crystal clear. However, it depends much on the capacity and power of the UV light. Some will take longer and some will take less time.
How to improve bacteria and algae control?
The main reason that causes algae and bacteria growth is the exceeded food and nutrients. To improve bacteria and algae control, you can use bioaugmentation containing beneficial bacteria & enzymes. These bacteria and enzymes help resolve the exceed food; moreover, it maintains the water’s PH, keeping the water clean and healthy for koi fishes.
Where do you put UV light in a pond?
UV lights are often for external use, which means you cannot submerge into the water. You can in-line install it after the filter. So, the water after being filtered to get rid of bigger bits of dirt will be filled in the UV light's barrel to remove microorganisms, such as bacteria, parasites, viruses, and even algae. Some UV lights include a filter; for these UV lights, you just need to place it directly to the pond.
A good UV light can keep your pond clean, clear, and healthy for Koi fishes. Hope that my review helps you to choose the best UV light for your Koi pond.