Well, if 7-11 sells it, it would probably be dirt weed! I think relocating your veg area is best. I'm thinking there are spores lurking in porus areas, wood, drywall, etc. Mature plants are resistant to damping off, but if you can, find another area even for the older guys. Could be other fungus type diseases lurking there too. Dont take the chance if you don't have to. There's products commercial greenhouses use to clean/treat surfaces for this kind of thing. I'm not sure if you can even get these products other than in large bulk packages. I always asked the boss if I could have a little & take home a coffee can full. Was a bitch trying to scale down from a 500 gal vat to a 2 gal sprayer! I'm NOT MATHEMATICAL !!!! I actually had to call an old college professor to do the equation! He was such a good guy. He'd do that shit for me without making me feel stupid, hell I could do that myself! LOL! The bad part was, couldn't measure it out with kitchen gadgets, I actually had to take it on campus & have him weigh it out on his calibrated uber sensitive scales. It wasn't even a pinch! See why I no longer use that shit!? But I'm so sorry dude. What you need for this thing you have is an EXORCIST! Keep us posted with how it goes when you change rooms. Seems like the only way to go.~~~PEACE!~~~~

I'd also get rid of the coco shit. Post #2 Shove suggested seed starter mix, good choice, or finely milled spaghnum moss & perlite.