At least you know you wanted to grow them brother
Ok brother, here's my five cents...
Those plants look really good except for some sides of some plants. What I mean is, there are several fanleaves which are clustered together that are showing a def/excess, which makes me suspect some root issue on that side of the pot. This is soil, no? If so, let it dry out a bit and water slooowly with a surfactant added to prevent dry pockets. Add some bennies to that water and lower the nutes until they are back up.
Now the EC, When I used the MC recipe I normally would feed them around 0.8, 0.9. I think you went a bit to high for these girls and are paying the price.
H2O2 to the resque
Didn't you soak your rockwool cubes into pH'd water?
I used to go 0.3 lower on mine in the day, then you want the cubes to become and after 24h the EC of the soaking water was perfect. Adding nutrients can be done, but do this at a very low EC. ie, 0.2 mS/cm or max 250µS/cm. And as soon as you start with nutrients you'll also have to feed to 20% runoff as otherwise the EC will rise while water evaporates from the cube faster then the seedling can uptake the solution.
Sorry to be a nitpicker, but I mean well