Circulating salt water in a seawater aquarium

Those seeking to create a natural environment for marine life must maintain the correct water quality and reef construction in the marine biotope. 

To this end, it is necessary to remove food residue, faeces and pollutants from the water circuit in order to keep the sea water clean. Filter systems are deployed to maintain the requisite levels of cleanliness. The water is cleaned when it flows over nitrifying micro-organisms. The water is filtered further through multiple layers of activated carbon and quartz sand, after which it is treated by UV systems for disinfection purposes. One million litres of water per hour are circulated through the shark tank alone, i.e. the whole water volume flows through the filter at least twice per hour. This process requires a high filtration capacity, as disinfectants – which would be have a deleterious impact on the fish – cannot be used in aquaria. 

Centrifugal pumps are used to circulate the water, which ensure an even flow of seawater. Since they have no metal parts that come into contact with the medium, they do not release harmful metals into the water which would cause serious problems, especially for sensitive fish species.