"Dave" wrote in message
...
Hi

We have just moved into a house with an existing pond. The pond has been
made using a some form of liner, but from the feel, ie I can easily push a
'dent' in base of liner so I don't think the original builder has put sand
underneath to support it.

I would like to add some rocks so that there is a rockery effect coming
from
the pond, because of the way the pond has been done, the only way I can do
this is to put the rocks in the water on the liner. My worry is that the
rocks may eventually puncture the liner.

I was thinking of putting a sheet of polystyrene packing under the rocks
to
protect the liner. Will anything leach out of the polystyrene that may
harm
the wild life? The pond is teeming with wildlife in the form of frogs and
newts which I would like to encourage and protect.


You could try using the felt underlay that is sold to put under pond liner.
In my wildlife pond I have completely covered the liner with the felt so
that you cannot see any of the shiny smooth surface. A couple of layers of
the underlay under the stones should be an effective cushion.

The underlay I used started off white in colour, but I rubbed clay soil into
it to darken it and now it looks just like a natural surface in the water.

--
David Jones
Garden Wildlife Diaries and Birdbox Webcam at
www.mybitoftheplanet.com