just make sure you always have fresh air in your room and dont let it get to humid, thats the key
Hmm, if it's mold, I've done a mixture of 10% baking soda in a spray on the leaves. That seems to be able to kill the crud and save the rest of the plant.
Just let the spray dry on the leaves and then nothing else will be able to grow.
That should help stop the problem without anyone smelling sulfur or even noticing anything different.
Anything that looks too spotty, I would remove as someone else said. You don't want that to spread around. It does spread quick.
Time to look at your grow room, my man, to make sure that things don't get moldy or mildewy the next time.
Good luck!