JBL ProCristal UV-C Compact Plus 36 W

JBL ProCristal UV-C Compact Plus 36 W is the largest UV-C clarifier in JBL's Compact Plus range at 36 watts, sized for big aquariums and garden ponds. It goes into the hose run from an external filter or a separate pump, and the ultraviolet light takes out the free-floating algae and bacteria that cloud water.

Key Features

• Aquariums and garden ponds: JBL lists it for freshwater and marine aquariums and for garden ponds, with the volume figures set out below.
• 36 W UV-C lamp: JBL rates this unit at 36 watts for the water volume it is intended to handle.
• Plumbs into a filter line: it sits in the hose run from an external filter or a separate pump, so nothing extra goes inside the tank.
• Shortest installation length 61 cm: measure the space you have before ordering, because this is the dimension that catches people out.
• Hose connections for 12 to 40 mm hose: JBL supplies the nozzle connections in the box.
• TUV tested with a safety switch: JBL's safety switch cuts the lamp automatically when the housing is opened.

What It Will Handle

• JBL's figures for partial sterilisation are up to 3000 litres in an aquarium with a pump of no more than 1000 litres an hour, or a pond of up to 15000 litres with a pump of up to 4000 litres an hour.
• Against free-floating algae specifically, JBL quotes a much smaller figure: up to 800 litres in an aquarium and up to 8000 litres in a pond, at the same pump rates.
• Those two sets of numbers answer different questions. Size the unit against the job you actually want it to do, which for most people is the green water one.
• Note the pump limits as well as the volumes. A pump that is too fast undoes the whole thing.

Using UV-C Safely

• Never run the lamp outside its housing and never look at it lit. UV-C burns eyes and skin, and the damage is not felt at the time.
• Switch the unit off at the mains before you open it, and let it cool. JBL fits a safety switch that cuts the lamp when the housing is opened, but treat that as a backup rather than the plan.
• Fit the unit after the filter, so what reaches it is already mechanically clean, and keep it below the water line only if the instructions allow it.
• Flow rate decides the dose. Pushing water through faster than the unit is rated for means it passes through without getting enough exposure to matter.
• Switch it off while you are dosing medication, a bacterial starter or a liquid treatment. UV-C breaks all three down.
• Clean the quartz sleeve regularly. Limescale and film on the glass cut the output, and in hard tap water that happens quickly.

Good To Know

• A UV-C unit treats the water that flows through it. It does nothing about algae on the glass, on rocks or on plants, and it is not a substitute for filtration or water changes.
• UV-C lamps lose output long before they stop lighting up. Plan on a new tube roughly once a year of continuous running, even if the old one still glows.
• Running UV-C continuously in a reef or heavily planted tank is a choice with trade-offs, since it also removes free-floating plankton. Many people run it only when they need it.
• JBL says the unit does not change the water values and does not affect the bacteria living in the filter.
• In the box: the complete unit, a 5 m cable, a 36 W UV-C lamp with a 2G11 socket, a wall mount, screws and the hose connections.
• Check the socket type and the lamp length against the unit before you order a replacement tube. The wattage alone is not enough to identify it.