New heat Matt compost recomendations

Just started using a 7 try heat mat had good success with it so far for germination. Problem I am having issues fungi growing in the compost after two weeks using a mix of cheap compost and Coco seed compost any recommendations or ways to sterilize compost before use

 

For seeds I just use the Coco coir on its own, I've never had any fungi.

 

The compost is too moist so you need more ventilation to prevent fungi.

 

But you need the fungi spores to be present in the first place too.

 

Fungal spores are everywhere all the time - when they come into contact with a suitable home they move in.

 

Well it depends what fungus he's getting doesn't it? If he's got oyster mushrooms growing out of his seed trays then it's probably the compost.

 

Mix 25% sharp sand in the compost before sowing it will help it drain, I've never gone to the lengths of sterilising compost, but some people do small amounts in a microwave.

 

If the conditions are suitable for fungi, there are probably several varieties involved.
To stop that happening and get rid of those already there it just needs less moisture in their environment, so more ventilation and a less moist compost will achieve that.

Most years I get some fungi appearing in seed trays in my heated propagator in my unheated greenhouse. By removing the lids during the day for a few hours and leaving the vents open all the time soon gets rid of them.