One of the most important pieces of information to know about your koi pond is it's exact gallonage, this is a vital figure to know in case you need to add treatments to the pond, but if you didn't fill it with the aid of a water meter first time around all is not lost.

The pond calculator will help you to find the water volume of your pond, but remember, your system includes filters and pipe work so use the same rules for establishing the volume of your filter system as well.