looks healthy. I agree they seem behind for 28 days but every plant is different and so is every grow situation. based on the photos they look like they have sativa in them so it could be a 9-10 week strain. I would just be patient. Happy growning!
keep it more dialed. Ph should be 5.6-6.0. 5.8 being the sweet spot. I always keep my temp at 67 but 65-70 should be fine. Also not to be a downer but switch out that waterfarm system asap, its junk.