Critical + 2.0 Deep Water Culture

Plants have really stretched and I have used High Stress Training to bend the tallest tops away from the lights. There is quite a variety in terms of the height of the individual plants and this grow would have benefitted from a SCROG net. Also there are a lot of scrawny side branches that I probably should have chopped early on. The tent is extremely crowded and I am having to defoliate throughout flowering to keep the bud sites exposed. I have one plant at the back corner of the tent that has only just started to show pistils i.e. it's a couple of weeks behind the others. No idea why. Anyone got any thoughts or had this happen from plants all grown from the same batch of seeds? Another issue I have is humidity. It is maxing out at 70% over a 24h period, which is too high for my liking. During lights-off time I am running a dehumidifier in the room where the tent is situated so not sure what else I can do to bring the humidity down. With the lights on, RH is around 60%. Generally plants are thriving with very healthy roots (see photo). Chiller is doing a great job keeping nutrient around 20C/21C so roots get plenty of oxygen.