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Fluval UVC Clarifier (In-Line)



Fluval UVC In-Line Clarifier

Fluval`s UVC In-Line Clarifier quickly and easily connects to most canister filter setups to eliminate suspended bacteria and algae for a clear, healthy aquarium. Its CCFL (Cold Cathode Fluorescent Lamp) technology attacks bacteria and algae by applying powerful, DNA-destroying UVC light emissions. This natural process is chemical-free and will not affect already established beneficial, surface-dwelling bacterial colonies. With its distinctive compact design, this unit fits neatly within aquarium cabinetry without cluttering existing filtration systems.

  • Suitable for use in both fresh and salt water
  • Eradicates suspended bacteria and algae in the water column that contribute to cloudy and green water, respectively
  • Helps prevent the growth of cyanobacteria that often smothers and destroys aquatic plants
  • Does not harm beneficial, surface-dwelling bacteria
  • Condensed design redirects water flow up, down and around the bulb to maximize contact time for effective clarification
  • CCFL (Cold Cathode Fluorescent Light) technology runs cooler than traditional UVC bulbs to last up to 30,000 hours (3X longer)
  • Easily fits within aquarium cabinetry without cluttering existing filtration setup
  • Quickly connects in-line to all canister filter hosing with an internal diameter of 5/8” (or 16mm), including all Fluval 07 and 06 Series filters
  • Multi-directional – works in either direction so there is no need to move existing filter setup
  • Energy-efficient – up to 80% less expensive to operate than competitive clarifiers
  • 4–24 hour timer included for optional intermittent use
  • Mounting hardware included

UVC In-Line Clarifier Specifications

Model A203
Dimensions 6.25"L x 5"W x 2.5"H / 6.25 x 13x 6.6 cm
Max. Flow Rate 245 US GPH / 930 LPH
Max. Operating Pressure 0.5 Bar
Suitable for Aquarium Volume 100 US Gallons / 400 Liters
Net Weight 0.6 lb / 0.295 kg
Power Consumption 3W
Power Cord Length 6 ft / 1.9 m
Connection 5/8" / 16 mm hosing
What`s in the Box
  • UVC Unit
  • 4-24 Hour Timer
  • 100-240V / 50-60 Hz Power Supply
  • 18.5" / 47cm Hose
  • (2x) Mounting Screws


Q: My aquarium is cloudy and smells bad. Will the UVC clarifier help?
A: If the cloudiness is due to suspended bacteria or algae, the UVC clarifier will indeed clear the water, provided it is installed as instructed. To help reduce smells, the best solution is the use of activated carbon. It is also advisable to investigate the source of the odor: if it is due to decomposing organic matter make sure to remove it and perform a regular partial water changes.

Q: Does the UVC clarifier prevent algae growth on surfaces within the aquarium?
A: The UVC clarifier will only neutralize suspended bacteria and algae, and as such will not prevent the growth of most algae on the aquarium glass, gravel, décor, etc. Some surface-dwelling algae species exist as spores at some life stages, however: the UVC clarifier will help prevent the growth of these species.

Q: Will using the UVC clarifier harm the beneficial bacteria in my aquarium?
A: The beneficial species of heterotrophic and nitrifying bacteria in an aquarium live on surfaces in the filter, in the substrate, on plants, etc. They do not live in the water column and as such are entirely unaffected by UVC sterilization.

Q: Will the UVC clarifier have any negative effects on the beneficial microorganisms in my reef aquarium?
A: The UVC clarifier may affect some beneficial microorganisms present in the water column, including ones that may be a food source for some species of fish and coral. In healthy reef aquariums, however, these microorganisms are very abundant and the UVC clarifier won’t significantly affect their population levels.

Q: Will the UVC clarifier help keep my fish from getting sick?
A: The UVC clarifier helps to keep aquariums clean and healthy, but it is not a treatment for sick fish. Please consult your local aquatics retailer or the Marine Depot customer service team for assistance in preventing or treating aquarium fish diseases.

Q: My fish have ich, will the UVC clarifier cure them?
A: In general, parasites are too large to be effectively terminated by UVC light. To treat ich, please consult your local aquatics retailer or the Marine Depot customer service team for assistance.

Q: I am treating my fish with medication. Should I continue to run the UVC clarifier while doing so?
A: In order to ensure the most effective treatment, the UVC clarifier should be unplugged while medicating fish.

Q: How do I know the UVC clarifier is working?
A: The 24-hour timer features an operating status light. If it’s green, the UVC bulb is functioning normally. If it’s red, the bulb has expired and the UVC clarifier must be replaced.

Q: How long should I run the UVC clarifier for?
A: We recommend first running the UVC clarifier intermittently, for 4 hours a day. If the desired effects are not achieved, gradually increase the amount of time the unit runs each day until they are.

Q: How will the UVC clarifier work following a power interruption?
A: The UVC clarifier will revert to the same operating time that was initially selected once it is reconnected to a power source. For example, if the timer was set to operate for 4 hours a day, it will continue to operate for 4 hours from the moment power is re-established. As the timer does not keep track of the time of day, if you want the UVC unit to run for 4 hours a day as of 8 am, for example, the unit should be connected to a power source at 8 am.

Q: What size hosing does the UVC clarifier accept?
A: The UVC clarifier connects in-line to all canister filter hosing with an internal diameter of 5/8? (or 16 mm), such as the Fluval 07 series.

Q: Does the UVC clarifier need to be mounted with the mounting screws or can it hang in-line with the hosing?
A: We recommend mounting the UVC clarifier with the two mounting screws provided. However, if you choose not to do so, the unit will still function normally.

Q: Is there a particular orientation the UVC clarifier should be mounted?
A: The UVC clarifier should be mounted vertically, with the mounting screws at the top and the hose connections at the bottom. This will help with weight distribution. However, if the unit is mounted in an alternate orientation, provided the mounting is secure, the unit will function normally.

Q: What makes a CCFL bulb better than traditional fluorescent bulbs?
A: A Cold Cathode Fluorescent Light (CCFL) runs cooler than a traditional fluorescent bulb and as such lasts up to 3 times longer.

Product Manuals & Documentation

Fluval UVC Clarifier (In-Line)

Owner's Manual available for download in Adobe PDF file format
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HG10203 Fluval UVC Clarifier (In-Line) // Fluval OutOfStock 99.99 USD 0.0 0