On 16/08/2014 22:30, Spider wrote:

Perhaps I'll just have to buy some and see if it sinks or floats. I'm
sure I could use the rest for top-dressing pots if I can't use it in the
pond.

You can sometimes find house plants in hydroleca in garden centres. If
you can find such a plant which is well past its best, you could ask the
GC if they will let you have it to try the hydroleca as a pond plant
medium. They might even have an area of plants awaiting disposal which
are in hydroleca, and you could get a potful for free.

--

Jeff