Pond Volume Calculator
Thought i would post this, might come in handy ! Theres a few Pond water volume calculators around put if your wondering what volume of water is in your pond for treating with disease control etc then why not try the link.
Theres also ways to work out what size pond pump you require based on the size of your pond and if your keeping Koi carp.
Here is a link that might be useful: Pond water volume calculator