Most folk have tried all sorts of liners for ponds, without problems.
There is the usual caution to 'wait' for pond water to mature and show
signs of algae and invertebrates colonising naturally, before trying to
put any fish in

~ Your pond is small, it is possible there is insufficient oxygen
overnight, if fish are showing up dead in the morning
~Tap water can be lethal to fish, if it is recycled and treated stuff
~Poisons may be accidentally or deliberately being applied, have lawn
treatments been leaching into the pond...
~There are some nasty fish conditions about, you might try
disinfecting, rinsing the pond, and getting fish from another source


Regards, andy
http://www.members.aol.com/abdavisnc/swglist.html

Andymcgoo wrote:

(difficult to test without the water) any way our fish still kept dying. so
we checked out just the water by putting fish in just a plastic bucket. low
and behold they live. SO WE HAVE A DODGY POND LINER the suppliers recon
there is nout wrong with it but as soon as you put a fish near it the go all
fins up.

Question has anyone else had pond liner problems?