Pond pump sizing is relatively straightforward.
- For any pond greater than 1000 gallons, use an external pond pump for best efficiency.
- For any pond less than 1000 gallons an external pump is preferred but a submersible pump will do the job.
How Big A Pump Do I Need?
Your pump should move the total volume of your pond in one hour. So if your pond is 500 gallons, the pump should be able to move 500 gallons of water per hour. If it is 5000 gallons, the pond pump sizing should be such that the pump is rated for 5000 gallons an hour. Or you have two 2500 gallon rated pumps.
The rule of thumb is that for good operation, your pump turns the total water volume over every hour.
Calculation – It’s basic math and here it is
So how do I calculate how big my pond really is? Funny you should ask. Here’s the math.
(A cubic foot contains 7.5 gallons of water btw)
Pond size in gallons= Length x Width x Depth x 7.5
So if your pond is 5 feet long by 3 feet wide and 2 feet deep. The math goes 5 X 3 X 2 X 7.5 = 225 (The pump should be rated for 225 gallons per hour)