this looks to me like a nute problem. First the edges are burned but i dont see the same on others, but those are micro nutes issues starting. some Cal Mag+ would help straighten that out before you get too far along. You are using a one part nute solution, so your micro needs to be adjusted some. I had the same problem with the Pro Grow and switch to the triflex and it corrected itself. you could prolly up your nute solution some and add a little calmag+ to it so that its getting the micro's that it needs