@GrowersWild Hi there mate You are in my opinion Overwatering and keeping the plants in too damp an environment
The leaf discoloration is caused from the plant being unable to uptake the required nutrients and the constant dampness is what is causing the fungal growth on the outside ogf the pots. I would repot them all into their final grow out containers , Feed with Calmag and then try to let the soil dry a little between waterings
The roots need air and you wont get the fungus growing onthe outside .