A water purification system and uses thereof

A circulating water purification system, the system comprising

• a tank or a container configured for holding live aquatic animals,
• a purification unit,
• at least one sensor,
• a controller, and
• optionally a water reservoir,
• the purification unit including a membrane or a filtering unit or a filtering medium or an adsorbent comprising M-HCF, wherein M is a bivalent metal and HCF is hexacyanoferrate,
• wherein the tank or container is in liquid communication with the purification unit to permit flow of water contained in said tank or container into and through the purification unit and to receive treated water existing the purification unit;
• wherein the at least one sensor is provided in said tank or container and is electrically connected with the controller;
• the sensor being configured and operable to detect and report to said controller a rise in a concentration of ammonium ions in the water,
• whereby the controller is configured to initiate circulation of the water through the purification unit, wherein the sensor is optionally a pH sensor.

A water purification system comprising:

• a water tank configured for holding live aquatic animals;
• a first auxiliary container for receiving a volume of water to be treated from said water tank;
• a purification unit or a unit containing M-HCF or a medium comprising same, said unit being provided downstream of the first auxiliary container and in fluid communication with the first auxiliary container for receiving the volume or water from the water tank;
• a second auxiliary container provided downstream of the purification unit and in fluid communication with the purification unit and comprising an outlet port arranged to communicate filtered water back into the water tank;
• optionally one or more purification units for comprising one or more of a carbon-based filter and a biological filter.