Purification Plant to the World’s Most Spectacular Aquarium

ELGA Process Water (UK), a Veolia Water Solutions & Technologies company, has supplied a second MidiRO reverse osmosis system to The Deep, in Hull. The Deep is a state of the art aquarium that combines education, conservation and research and is home to over 3,500 freshwater and sea fish including spectacular sharks and rays.

The welfare of the fish is of paramount importance and water treatment is critical. Ben Jones, The Deep’s Senior Aquarist, explains: “Fish excrete high levels of ammonia. The water is continuously circulated through a biological treatment plant that converts the ammonia into nitrate but we have to control the nitrate concentration by discharging some of the water to waste and replacing it with make-up water.” And this is where the reverse osmosis system comes in. Make-up water is taken from the mains supply, pre-treated by a Selectron low salt usage softener before passing through the MidiRO’s low pressure reverse osmosis membrane which removes over 95% of the dissolved salts whilst minimising energy consumption and thus helping to keep operating costs low. The Deep can then re-mineralise the purified water under controlled conditions to give the precise chemical constituents for their freshwater or seawater aquaria. As a bonus, the reverse osmosis treated water is pure enough to be used in The Deep’s laboratories for glassware washing and reagent preparation.

The new compact treatment plant serves The Deep’s quarantine facility, where sick fish can be isolated and treated. “We decided to install a dedicated treatment system for the isolation tank,” says Ben. “We were very satisfied with the ELGA Process Water unit on the main aquaria so it was logical to use the same technology, and it means that both plants are covered by a single AQUAservice service contract.”