Neil Jones wrote:

Can anyone suggest a better medium to prevent damping off problems.
I have beein using coir fibre and I find that even with cheshunt
compound I am still getting problems with certain seeds going moldy.
This is particularly the case with my heated propagator.

What are you trying to grow ? Sterilising the seed surafce may be one way out.
(but then some plants need their fix of sympathetic fungi to grow successfully)

Any copper based fungicide ought to keep damping off under control. Better
ventilation will also help.
(or the other extreme completely sterile growing conditions but that is much harder
to do)

Vermiculite or perlite are possiblities. Which is best? I am a
conservationist and I love wild plants and their habitats too so I do
not wish to use any products containing peat.

Perlite isn't bad as a near sterile medium (mind the dust). I find vermiculite
collpases and clags too easily.
It also regulates water availability too.

Regards,
Martin Brown