BoyPete wrote:

600 gal pond, London UK. Hozelock pump and pressurised filter, plus
fountain. The fountain and filter return are creating a foam which clings
to plants and feeding ring. I assume it does no harm, but is there any way
I can illiminate this?

The foam itself does no harm, but it's caused by decayed materials - which
might - so you need to start by scooping out the foam, then any mulm on the
bottom of the pond.
--
derek