Hey, Is that fiberglas insulation? If so, even with the backing on it, you will get an ass-load of glas coating your sticky buds. At night time and with lights out, shine a flashlight from floor up. If you see a particle cloud in the beam of light then I would move them to a different location. Or finish the entire attic and vaccume every inch when done. If the space does have a ton of particulates, Even with an enclosed/sealed space within the attic, the amount of air that rushes in when you open it will heavily contaminate the bud by the end of bloom. Trust me, it will make your bud taste like total ass.(tried to convince a buddy one time, wouldn't listen) I use a sealed space with filters on my passive intakes and even though mine are in a pretty clean living space, I have to change the filters several times durring flower, they catch all the fine lint and carpet fibers that are always floating around. I'm very maticulous and maybe a little OCD too though. Just something to consider. Just noticed pic #2, what is that soil? Looks like it has pine bark and rocks in it.