The complete line, consisting of Fluval U1, U2, U3 and U4 Underwater Filters, includes many practical and versatile features that make them ideal for application in freshwater and marine environments. Fluval U series filters provide the option of setting the flow output in 3 different positions, a key benchmark in underwater filtration. The Adjustable 3-Way Flow Control feature (U2, U3 and U4 models) lets you position the water flow output to meet your specific needs. The Top Output setting provides maximum circulation and oxygenation, the Integrated Spray Bar setting provides a gentle, even flow for planted aquariums, and the Bottom Output setting is for deepwater agitation. Fluval U Filters also include a convenient flip-top lid that allows quick and easy access to the filter cartridge for maintenance or replacement including Fluval’s Clean & Clear cartridge. Packed with special high performance resins, Clean & Clear is proven to reduce phosphate and nitrate while preventing the spread of algae, providing you with a cleaner, clearer aquarium and healthier fish for longer intervals. In addition, Fluval U Filters offer installation versatility: they can be installed vertically against the aquarium wall to create currents or customized flow patterns; or they can be placed horizontally in shallow water tanks or to create decorative features such as waterfalls. Use the U1 as a primary filter in smaller aquariums or as a supplementary filter for larger aquariums. It is also ideal for tanks with low water levels. The U1 includes an adjustable flow control and comes complete with 1 foam pad.
The complete line, consisting of Fluval U1, U2, U3 and U4 Underwater Filters, includes many practical and versatile features that make them ideal for application in freshwater and marine environments. Fluval U series filters provide the option of setting the flow output in 3 different positions, a key benchmark in underwater filtration. The Adjustable 3-Way Flow Control feature (U2, U3 and U4 models) lets you position the water flow output to meet your specific needs. The Top Output setting provides maximum circulation and oxygenation, the Integrated Spray Bar setting provides a gentle, even flow for planted aquariums, and the Bottom Output setting is for deepwater agitation. Fluval U Filters also include a convenient flip-top lid that allows quick and easy access to the filter cartridge for maintenance or replacement including Fluval’s Clean & Clear cartridge. Packed with special high performance resins, Clean & Clear is proven to reduce phosphate and nitrate while preventing the spread of algae, providing you with a cleaner, clearer aquarium and healthier fish for longer intervals. In addition, Fluval U Filters offer installation versatility: they can be installed vertically against the aquarium wall to create currents or customized flow patterns; or they can be placed horizontally in shallow water tanks or to create decorative features such as waterfalls. Use the U1 as a primary filter in smaller aquariums or as a supplementary filter for larger aquariums. It is also ideal for tanks with low water levels. The U1 includes an adjustable flow control and comes complete with 1 foam pad.
The complete line, consisting of Fluval U1, U2, U3 and U4 Underwater Filters, includes many practical and versatile features that make them ideal for application in freshwater and marine environments. Fluval U series filters provide the option of setting the flow output in 3 different positions, a key benchmark in underwater filtration. The Adjustable 3-Way Flow Control feature (U2, U3 and U4 models) lets you position the water flow output to meet your specific needs. The Top Output setting provides maximum circulation and oxygenation, the Integrated Spray Bar setting provides a gentle, even flow for planted aquariums, and the Bottom Output setting is for deepwater agitation. Fluval U Filters also include a convenient flip-top lid that allows quick and easy access to the filter cartridge for maintenance or replacement including Fluval’s Clean & Clear cartridge. Packed with special high performance resins, Clean & Clear is proven to reduce phosphate and nitrate while preventing the spread of algae, providing you with a cleaner, clearer aquarium and healthier fish for longer intervals. In addition, Fluval U Filters offer installation versatility: they can be installed vertically against the aquarium wall to create currents or customized flow patterns; or they can be placed horizontally in shallow water tanks or to create decorative features such as waterfalls. Use the U1 as a primary filter in smaller aquariums or as a supplementary filter for larger aquariums. It is also ideal for tanks with low water levels. The U1 includes an adjustable flow control and comes complete with 1 foam pad.
The complete line, consisting of Fluval U1, U2, U3 and U4 Underwater Filters, includes many practical and versatile features that make them ideal for application in freshwater and marine environments. Fluval U series filters provide the option of setting the flow output in 3 different positions, a key benchmark in underwater filtration. The Adjustable 3-Way Flow Control feature (U2, U3 and U4 models) lets you position the water flow output to meet your specific needs. The Top Output setting provides maximum circulation and oxygenation, the Integrated Spray Bar setting provides a gentle, even flow for planted aquariums, and the Bottom Output setting is for deepwater agitation. Fluval U Filters also include a convenient flip-top lid that allows quick and easy access to the filter cartridge for maintenance or replacement including Fluval’s Clean & Clear cartridge. Packed with special high performance resins, Clean & Clear is proven to reduce phosphate and nitrate while preventing the spread of algae, providing you with a cleaner, clearer aquarium and healthier fish for longer intervals. In addition, Fluval U Filters offer installation versatility: they can be installed vertically against the aquarium wall to create currents or customized flow patterns; or they can be placed horizontally in shallow water tanks or to create decorative features such as waterfalls. Use the U1 as a primary filter in smaller aquariums or as a supplementary filter for larger aquariums. It is also ideal for tanks with low water levels. The U1 includes an adjustable flow control and comes complete with 1 foam pad.
Last updated at 06/18/2026 11:00:55
Fluval U1 Underwater Filter, Freshwater and Saltwater Aquarium Filter, A465
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Fluval New U-Series U1,U2,U3,U4 Internal Filters Submersible Aquarium Fish Tank
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Fluval Mini, U1, U2, U3, U4 Underwater Internal Aquarium Fish Tank Power Filter
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Fluval New U1 Internal Filter Submersible Adjustable Aquarium Fish Tank
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Fluval U1 Internal Aquarium Filter For Fresh / Saltwater Fish Tanks Up
Free delivery
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Fluval U Internal Filter - U1
Free delivery
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Fluval U1 Internal Filter (a465)
Delivery $9.99
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Fluval U1 Aquarium Internal Filter 250L/h for tanks up to 55L
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originally posted on petworlddirect.ie
It's great value and so queit in the tank. So easy to set up. You can also adjust the flow and spray bar
originally posted on walmart.com
I bought filters that were $100 and worked like crap. This filter keeps my turtle clean and she's in a kiddie pool so there's a lot of filtering going on. Definitely worth the money.
originally posted on hugglepets.co.uk
Not the best filter, I bought this to change from my old 3Plus, I have a 34L tank and the 3Plus was a bit strong for the fish. Since fitting the U1 my water has gone cloudy and isn’t filtering a lot. Obviously the 3Plus is better but the U1 is meant to work for a tank my size.
| Product dimensions | 10.16 x 7.62 x 15.24 cm; 398 Grams |
| Is Discontinued By Manufacturer | No |
| Product grade | Replacement Part |
| Style | Underwater Filter |
Fluval U1 Underwater Filter, Freshwater and Saltwater Aquarium Filter, A465
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Fluval New U-Series U1,U2,U3,U4 Internal Filters Submersible Aquarium Fish Tank
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Fluval Mini, U1, U2, U3, U4 Underwater Internal Aquarium Fish Tank Power Filter
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Fluval New U1 Internal Filter Submersible Adjustable Aquarium Fish Tank
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Fluval U1 Internal Aquarium Filter For Fresh / Saltwater Fish Tanks Up
Free delivery
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
It's great value and so queit in the tank. So easy to set up. You can also adjust the flow and spray bar
I bought filters that were $100 and worked like crap. This filter keeps my turtle clean and she's in a kiddie pool so there's a lot of filtering going on. Definitely worth the money.
Not the best filter, I bought this to change from my old 3Plus, I have a 34L tank and the 3Plus was a bit strong for the fish. Since fitting the U1 my water has gone cloudy and isn’t filtering a lot. Obviously the 3Plus is better but the U1 is meant to work for a tank my size.
They are quiet. Thats why I buy Fluval. My last one lasted 20 years
I use the U3 in my 40 gallon turtle and goldfish tank (big waste producers); it's the best filter I've used so far, and its unique in-tank design is marvelous.It needs a little help moving the water (my tank is heavily "planted"), and it's not as strong as it was when I first got it, but I would still recommend this as a good in-tank filter.It's very quiet when the water level is maintained, a
Fluval products are one of the best products in the aquarium business. They do the job well, leaving a lovely clean home for your little swimmers
I use it for a single RES. My water has been crystal clear for 2 and a half weeks and I didn't need to change a single pad. I am waiting for it's breaking point but I doubt there is one. My tank is 50 gal. you really get what you pay for.
Very professional to deal with.
Purchased the fluvial U1 filter as my U4 broke and was probably oversized. Product has been working well for a week, hopefully will continue to function.
| Product dimensions | 10.16 x 7.62 x 15.24 cm; 398 Grams |
| Is Discontinued By Manufacturer | No |
| Product grade | Replacement Part |
| Style | Underwater Filter |
