I just got done posting in another thread how using GH is so easy it's like cheating then I click on this interesting thread. Your video is fine and I like your small set up. At around 1:30 mark I was wondering about your ph because they look a little pale. Then around 2:00 looking at your day 48 plants I'm thinking, yeah getting a little over fertilized but not sure exactly what. I like to gauge my gut feeling before I find out the specifics. Then I see your nute mixing regimen and my eyes start to glaze over because I hate math but it seems you are on top of it. Then we get to the EC and my jaw drops. I guess I know nothing about Jacks. I have no doubt some plants can survive and maybe even thrive at 2.4 EC. I know for a fact mine would not, don't even need to try it. I think you are on the right track going back to 1.2 EC. If you want to try more sometime try 1.5 or so. Since I really know nothing about Jack's and have no idea how complete it is I will defer to the Jack experts from here.