200 Level 201 - Chapter 1
Pump Sizing
For ponds up to 5000 gallons, the rule of thumb is to size the pump to turn over all the water at least once an hour, so a 3000 gallon pond would require a 3000 GPH pump. However, this minimum often falls short of the desired visual effect. For example, let’s consider the size of a pond of about 2250 gallons. There are 7½ gallons in a cubic foot of water, so a 2250 gallon pond would be 2250 divided by 7½ or 300 cubic feet. This would be the volume of a pond 2’ deep by 10’ x 15’. With the waterfall at the far end of the pond, around 20 feet away from the viewer, 2250 GPH might fail to impress. It turns out that most folks want visual effects – a gentle trickle, a sheeting curtain, a white water cascade – that require more than the bare minimum circulation requirement. Luckily, there’s an easy way to size the pump by the visual effect desired and the width of the waterfall.
For ponds up to 5000 gallons, the rule of thumb is to size the pump to turn over all the water at least once an hour, so a 3000 gallon pond would require a 3000 GPH pump. However, this minimum often falls short of the desired visual effect. For example, let’s consider the size of a pond of about 2250 gallons. There are 7½ gallons in a cubic foot of water, so a 2250 gallon pond would be 2250 divided by 7½ or 300 cubic feet. This would be the volume of a pond 2’ deep by 10’ x 15’. With the waterfall at the far end of the pond, around 20 feet away from the viewer, 2250 GPH might fail to impress. It turns out that most folks want visual effects – a gentle trickle, a sheeting curtain, a white water cascade – that require more than the bare minimum circulation requirement. Luckily, there’s an easy way to size the pump by the visual effect desired and the width of the waterfall.
