Normal growth, slightly overfed. Long twisting leaf tips most often means you're feeding a little to strong sauce.
"Dry backs" is not advisable when growing in soilless with that amount of perlite, it's practically impossible to over water your medium. It only needs to be properly cycled and replenished.
Let it go lighter but never let the surface dry out. Drying back to much between watering negatively affect root growth, yield and potency. There's a lot of misconceptions on this site regarding watering and feeding frequency.
Hope that helps!
Cheers!