I am new at this and am attempting an 11x14 yard pond. Can you tell me the best (and cheapest) liner out there to use? This is my first, but hopefully not my last. My husband has a lawn maintenance/landscaping business and we are hoping to be able to start building yard ponds too as we have had a lot of requests for this ...but first we are experimenting in our own backyard. Are there other alternatives to regular poly liners? Thanks.