by the way that fluffy brown stuff on ur driftwood i think is algae..u shud hav boiled it..anyway take it out clean it and boil bfore putting it back in..otherwise it vil start floatin around in the tank
is it a whitish fuzz on the driftwood? well get some sort of algae eater that suits the tank. i have had this happen to my tanks when adding new driftwood(that wasnt boiled beforehand). when i did some research i found that it could be a type of fungus or algae. Went out and bought one and he loved it, and cleared it up in 2 days.
I'm willing to bet your FH will kill/terrorize that Pleco to the point where it won't even come out even at night. Don't get a pleco for an easy fix, just take out the wood and do it yourself.