The new Harry Potter movie "Harry Potter and the Goblet of Fire" not only features wizards and magic, but also high-tech water treatment. For the lake scenes, which had to have crystal-clear water, two UV Astron ultraviolet disinfection units from the Wallace & Tiernan product line were paired with an Ezetrol chlorine residual controller and EzeFloc PAC (polyaluminum chloride) dosing sets from the Stranco product line. Siemens personnel were on hand during the June to December 2004 filming, to ensure the equipment functioned properly and to train the lake scene filming crew.

"The lake was an important setting in this movie," says Barry Humphries, sales manager of Siemens Water Technologies. "So the water needed to be absolutely crystal-clear for the extensive underwater scenes. The actors were extremely happy with the water quality."

The UV Astron units inactivated any microorganisms in the pool water, ensuring the water was safe for the actors who spent considerable time in the set-designed lake. Dosing the lake with EzeFloc Aktiv then kept the water clear by quickly forming a highly active floc that bound the resulting suspended solids and prevented them from passing through the filter bed. Finally, the Ezetrol controller measured chlorine and pH levels to comply with specific disinfection parameter set points. This combination was important for the film crew, as it helped to provide a water quality suitable for long periods of underwater filming and time spent with the actors in the pool.