6 weeks . I think the thread is still on the site I posted it.
Drooping can be from a lot of things not just overwatering. Could of been a nutrient lock out from salt build up, we don't know what he's using . It is pretty damn difficult to overwater coco, it'll just piss out the bottom. But sure perlite is the cure. Op is not doing enough plants per light . 7 or ten gallon pots you should be doing 4 per light minimum. His plants and huge I highly doubt he's overwatering his plants. I don't recall reading anything about how often he's feeding? What else is wrong in his room? Were trying to help the guy not bash him, share with us your wealth of information