Underwater World – UV disinfection for sea water aquarium


Merlin Group – Underwater World, Mooloolaba QLD


UV disinfection system for an aquarium filled with sea life


Underwater World in central Mooloolaba, located in the heart of Queensland’s famous Sunshine Coast is renowned for being the area’s top family attraction. The aquarium is home to a range of marine life including fish, sea animals and corals.
The marine life must be protected from a range of diseases including bacteria, fungi, viruses and protozoa. If infection were to occur, fish and other marine life could perish and the aquarium would suffer substantial financial losses. To protect the marine life the sea water must be disinfected. The water must then be monitored to ensure that the chemical balance, pH, and temperature levels remain stable. This safeguards the life, health and comfort of the ecosystem’s inhabitants.

The most effective way of disinfecting the water is by using Ultraviolet (UV) light where 254nm of UV deactivates the micro-organisms DNA.


  • High peak flow rate of 720 m3/hr
  • UV dose of 40 mJ/cm2
  • UV Transmittance ({973a8d5d966004f43fb86d9a31a852f076f10d3974a81c4d48a1dcd3f335f6f0}UVT) of 98{973a8d5d966004f43fb86d9a31a852f076f10d3974a81c4d48a1dcd3f335f6f0}
  • Able to treat seawater high in Total Dissolved Solids (TDS)


  • UVG P9-440

UV Guard provided a custom built UVG P9-440 to meet Underwater Worlds specifications. The P9-440 is specifically designed to disinfect sea water. The chamber is built from polyethylene so will not corrode when exposed to sea water. The sea water continuously flows through the polymer reactor to maintain the health of the fish and animals at Underwater World.

The P9-440 comes complete with nine 450W UV lamps and UV intensity monitoring to alert the customer whenever the design UV dose is not being achieved. This may be as a result of quartz tube fouling, lamp failure or deterioration in water quality.

If you have aquaculture water treatment enquiry, contact a UV Guard process engineer today.