Collection: UV Sterilizers

A UV unit only treats water inside it

Whatever passes through the chamber receives a dose; whatever stays on the rock, the glass or a fish does not. That single point is where most misunderstandings about UV begin. It is water treatment rather than tank treatment, and the figure governing it is flow rate, not tank volume.

What this category holds

• In-line sterilizers across a spread of wattages, fed by a return line or a dedicated pump.
• Hanger and submersible units for systems with no practical plumbing run.
• In-line clarifiers that add UV to an existing canister filter loop.
• Bulbs and quartz sleeves catalogued by wattage.
• Ballasts, brackets and silicone lubricant for the O-rings.

Running a unit well

• Contact time falls as flow rises, and a stated wattage assumes the maker's rated flow.
• Output declines while a lamp is still lit, so change bulbs on schedule rather than on failure.
• A film on the quartz sleeve absorbs UV before it reaches the water. Clean the sleeve at service intervals.
• Never operate a lamp outside its housing. UV is harmful to eyes and skin.