So I've dabbed the dwarf hair grass and substrate around it with witch hazel. It's all I had in the house. It seems to have worked. So far...
But I also realized there really wasn't any air circulation, so I've left a corner open all day now, lets some air exchange happen, hi this help the fungus/mould.
I never filled the bottom layer of tank with water and substrate is jugs barely damp to touch so I'm surprised I was getting mould/fungus? Frustrating!
my other expensive hobby....my golden retriever "Samson",