[header] How to build a koi fish pond [title] Buy all your supplies. [step] These are listed below under " things you'll need ". You might want to hold off on the koi until the pond is ready though, especially if you're slow at digging and don't foresee completing this project in an afternoon! [title] Measure the plastic pool as best you can using a measuring tape. 
[title] Dig an appropriate hole for the pond, going by the measurements you've made. [step] Choose a flat, available area of soil.