Plant looks a lot better, leaf tips look a little burned, maybe over fertilized liked Scorpio pointed out.
My only concern would be the color of your roots. some look a little brown and some look green, like algae. Does any light penetrate your grow tub?
I might get beat up a little for saying this, but part of your problem might also be using Cal/Mag as a additive. Combined with your GH nutes, you might be over doing it with the Cal/Mag and it could be why some of your roots are brown and leaf tips burned.
Overall, plant looks good, just some minor tweaking and you should be fine.
AzLaker