Circulation Pumps

Circulation pumps push water around the display rather than through a filter. They break up the dead spots where detritus settles, keep temperature even across the tank and give corals or plants the movement they want.

Sizing

Flow rate against tank volume is the main number. Reef tanks generally want considerably more turnover than a planted freshwater tank, so a pump chosen for one is often wrong for the other. Placement matters as much as the rating: a pump aimed at the glass diffuses flow, while one aimed along the back wall creates a circular current. Mounting style, magnet or bracket, has to suit your glass thickness.

These are commonly bought with a magnetic cleaner and a spare impeller.

Sump and overflow parts are on the Plumbing page.