One think I would do is finished this grow and start a total new grow with all clean fresh equipment. I've seen mold rip a garden down in under 24hrs when it gets a grip it can be very bad.
I would personally finish this current grow. Give you grow environment a good clean and remove any old medium etc. Then start a fresh
I even do the carbon filter covers everything where a possible mold could hide it ugly head
All the best
D-M.