Hello everyone....My name is Patrick, from central Indiana. We've got a 10'x12'x40" pond w/koi, goldfish, and shubunkins. we've had our pond for roughly 6 yrs, with us redigging it 3 yrs ago do to the liner cracking. Starting out w/5 fish, we have grown to 14 or so. We stumbled upon this forum while looking up how to do a DIY biofilter. love all the info we have found so far. Planning on moving this summer and doing a pond at the new place. Is there any other options to a liner other then a liner? I know we could do concrete but that would probably end up cracking.