Mould should only be problem for wheat & sunflower in warm humid weather.

Step1:- add 1/3 teaspoon of Bi-Carb Soda to the seed soak & use this solution to mix with the seaweed when preparing the coco fibre.

Step2:- after 2 to 3 days remove the germination cover & cover the sprouted seeds with a fine layer of dolomite, this will sit on top of the seeds creating an alkaline environment, but probably more important it will absorb any moisture from around the seeds making it difficult for the mould to get started. The mould starts when seeds become too moist & start to rot, especially un-germinated ones, each time you remove the germination cover for inspection give the seeds a spray with the MgCh water.

Optional:- I also, when I remember, add 5ml of food grade 35% Hydrogen Peroxide to my watering can, whenever I fill it up, also helps to reduce any odours.

Also for larger seeds like peas & sunflower get rid of damaged seeds at the start (Peas) & pick out mouldy ones as they develop.