Hi,
Whenever I get that kind of mold, I find there's only one thing that can work, and that's repotting. Open air, fungicides, and manual removal seem worthless against it, in my experience.
Just remove as much of your plants as you can without including anything near that mold. (stay at least an inch away from it, even more would be better)The less soil you bring along to the new pot, the better too. You might want to rinse away all soil traces before adding it to the new pot.
Take care!
Chris