Fountain Pump Sizing: Flow and Head for Each Jet

A fountain pump is chosen like any other pump, by flow and head, but fountains have a few traps.

Jet height is not pump head

The water loses energy in the pipes, valves and the nozzle itself, and in the air on the way up. The pump head must cover the nozzle’s required pressure for the jet height you want, plus the pipe losses from the pump to the nozzle. Use the nozzle maker’s figure for the pressure and flow at a given height.

Nozzles set the flow

Add up the flow of every nozzle a pump feeds. A ring of small jets can need as much water as one large central jet.

Split by effect

• Give each effect, a central jet, a ring, a curtain, its own pump if they are switched separately
• For music fountains, choose pumps that can be switched or speed-controlled by the fountain controller
• Where people can reach the water, consider 24 V low-voltage DC pumps

Keep the pump under water

Fountain pools are shallow. Check that the pump stays fully submerged when the jets are running and the water is up in the air, and fit a strainer to keep leaves out.