I was doing a bit of cleaning around the farm yesturday and guess what slapped me in the face. An old water bed bladder, I did my calculations and I could maximize the size of it and get a square pond thats 4' x 4' x 2' that would total 240 gallons. But here's a killer idea for anybody. Companies that install pools and maintain them are alwayts replacing liners. And the ones with rips in them are always thrown out and some pools go up to 20,000 gallons and the companies have to pay to have the liners destroyed and well they'll be glad for you to take them off there hands. So thats my figuruing on how to get a huge free liner.

oooh! that's a neat idea! i never knew the pool companies want to get rid of their liners LOL, i'll have to call and ask if my dad wants to build another pond LOL

I would just be careful with pool liners - there could very well be some residue from chlorine and other chemicals that has been used to maintain those pools. And about that water bed bladder - I don't know if they are made in a safe way, since it isn't actually something that ever is intended for human consumption - obviously. Those things aren't always food safe, and therefore not fish safe either.

I'd be hesitant to use either of those liners. Plastics is porous and can easily absorb stuff including chlorine.

IF you choose to use one or the other I would fill with water, let sit for a few days and then use a chlorine test kit to test for chlorine.

Personally for the risk involved for fish friends that liner is too expensive compared to buying fish safe epdm rubber

Well, you might as well try!