Quote Originally Posted by fred View Post
As far as I know there is no liner available here... But even if there were I would use concrete every time because of the bottom drain system.. The bottom drain is at the deepest part of the pond and everything slopes downward towards it..Just before the drain inlet there will be a small concrete vortex.. That vortex will pull in fish waste and algae when the pump operates which then goes into the concrete settling tank..
You can do this with a PVC liner but imagine the nightmare if you ever had a tear or leak??
Absolutely no reason not to use concrete IMO although some say it raises PH.. This is completely untrue.
Concrete ponds done properly should last a lifetime and are pretty much maintenance free.
in past concrete or cement work iv done, to waterproof i added pva to the mix, also when the cement or concrete drys it is much tougher and less likely to crack,

but if you use it find out if it is none toxic once dry, i think myself because it is hard and water tight, it wont contaminate the pond water