Originally Posted by
FRK
I copied this advice from a poster on another forum so I could post it here for you.
"you don't. You use fold the corners like "hospital corners" sheets. That means the excess is folded behind, not in front, of the liner along the walls. You can then take the exra step and use liner tape to seal the single vertical seam in each corner.
I put a foot of water in our pond to hold down the floor while I folded the corners. Once that was done, I sumped out the water and then cut in the bottom drain holes, TRP holes, and skimmer. After those cured for 24 hours, I filled the pond and cranked up the system."