Having trouble with two of four plants, growth stunted, no new growth in 2 days. #1 and #2 thriving, #3 and #4 stunted. Can they recover? Using 100% coco medium in 1gal fabric pots, watered with 200ml pH 6.0 water on 02/21 and 02/22. Each plant gets 300 PPFD in 18/6 schedule.