Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I would not try to go too deep. Wider, longer is better so that there is more surface area to be better aerated.
To figure out pond liner is simple math.
If the pond is rectangular then start thinking along these lines:
Start at one side. Allow at least a foot to lay flat on the ground.
Then go down the side. (How deep is the pond? Lets use 4' as the number) so you are up to 5'+
Now go across the bottom. 7' plus the 5 from before = 12'
Now up the other side 4' and some to lay flat on the ground, 1'. Add to the 12' and that makes it 17' long.
Do the same in the other direction.
1' + 4' + 10' + 4' + 1' = 20'
So you need a piece 17' x 20'. If you want to go deeper, then substitute your numbers in that formula going both ways.
If you will have a sump, water fall or other thing get a bigger piece.
Hint: if the whole pond is level and the waterfall comes in from over the side the liner does not have to be connected to the rest of the pond. It can simply overlap where the water falls in. That might make a slightly smaller piece.
Shop on line and check out feed stores, pond stores and anywhere else that might sell it. Remember to add shipping, pond liner is HEAVY.
You might see Xavan listed as pond liner, as thinner, but just as strong (it seems to be) and more flexible because it is thinner. (It is not).
Unless there is a big savings I would not bother to get Xavan over the 40 mil EPDM that is more commonly sold for this purpose.
DO NOT plan on skimping and patching together pieces. Buy enough to do the job with one piece.