Plant problem

I have a blueberry fem that is sick idk what the prob is. I'm in fox farm soil I do have nutes but I have not been feeding because I haven't really needed too. Please take a look at my pics. There's a over all pic and there's a pic of one of the sick leaves. I think it's a cal/ mag prob. But I'm not sure...

Thirps or some other leaf juice sucking bug. They'll attack a single leaf then move to another. The damage won't be all over the plant. After they suck a spot on the leaf, the tiny areas will die. Causing erratic white turning to brown spots on one leaf.

Otherwise. Your plant is healthy.