It is important to know the volume of water in your backyard pond for a couple of reasons. When you are constructing your water feature, you will need to know the volume it will hold in order to get the correct size pump to recirculate the water effectively. Poor water circulation will result in a unhelathy pond for plants and fish alike.
Secondly, knowing how much water is in your pond is imperative to maintaining a healthy ecosystem for plants and fish. Water treatments for fish and algae growth depend on proper dosing to work effectively. Not knowing your pond’s volume can result in either over- or under- dosing. This can result in wasting money and/or disrupting your pond’s environment. So here are two easy formulas for estimating pond water volume.
Rectangular Ponds
Average Length X Average Width X Average Depth (in feet) X 7.5 = Volume in Gallons
Circular Ponds
3.14 X ( 1/2 diameter X 1/2 diameter) X Average Depth X 7.5 = Volume in Gallons


