I live in the UK and have recently had some success in germinating and growing on ensete glaucum and ventricosum seeds

they are still young, but fingers crossed.
I use coir pots that you plant on without removing the seedling. I sterilised everything in the microwave and I water with a weak solution of cheshunt compound (copper sufate based fungicide), but there is a dubious looking fungus growing on the outside of the pots that seems to be immune to copper sulfate. I suspect that it is a fungus I have transfered from my fingers. Does anyone know if this could be potentially harmful to my little seedlings? If so what other fungicide could I use?
Also I'm looking for some musa cavendishii super dwarf seeds/pups, does anyone know where I can get them?