"Ian" wrote in message
...
The tadpoles have died, the fish have died. When I switch the fountain on
white froth appears on the surface. Any ideas ?
Ian


Suggest that you leave the fountain on full time - if there is anything
taking away the oxygen in the water this will replace some of it, and if
there are toxic gasses then this will help to disperse them.

You don't say how large the pond is, or how much vegetation you have to keep
the pond healthy.

If there is anything worth saving you could bucket water out of the pond and
replace it with rainwater or tap water.

For a small pond with drainage around it you could even put the hose in and
flush the pond out with running water.

Whatever has happened it looks as though the water is bad and needs
refreshing and/or changing.

If you have any fish left (swimming or floating and twitching) getting them
into fresh water, even a bucket full from the tap, could save them.

HTH
Dave R