The sump achieves three key functions:

• Water management re: evaporation top up with RO (Reverse Osmosis) water, salt water replenishment, and temperature control.
• Water treatment re: biological and mechanical filtration, sterilisation via UV,  and the calcium reactor.
• Circulation re the two main high volume pumps that feed the display tank.

The water volume in the sump is c. 140 litres / 30.79 UK Gallons / 36.98 US Gallons

The refugium is illuminated 24 hours a day, with a low wattage fluorescent