Yea, I think it's a toxicity, too. Toxicities can lead to deficiencies of other things and then entire system gets out of whack. You can't lower the EC and keep the PPM the same, they are one in the same. In LP aero, I'd bring your EC down to 1.0 running autos, and run ONLY your base nutrients for flowering. Add some candy at 1/2 strength if you like, but I'd halt the rest. Me, I just use the same thing the entire grow from veg to finish, with the exception of Clonex in the seedling stage. It's always 400ppm of Jack's Hydro, 280ppm Calcium Nitrate and 80ppm of Epsom salts, and a splash of ORMUS water once in veg and twice in flower. I change the res every week on Wednesdays or Thursdays (tomorrow I'll be at the state house welcoming in the new legislative session, so Thur will be change day) and replenish with the same base. That ratio is what I use in flower, so nearly 1.6 EC. I take my base solution (mix in 35gallon containers) and dilute that down to around .9 EC for autos in aero. I run RO/DI water, starting at 0ppm. So far, so good. I don't use any enhancers except ORMUS and soon to start using some sea solids for extra minerals and elements. But that's as fancy as I get.