Looks good so far. The HC is spread nice and evenly. I would wait a total of 2-3 months before filling it. It should be very nice by then. Be sure not to mist it past the level of substrate. I'm not sure if this happens all the time, but a 3x3 part of my substrate was a little deeper than the rest for some reason. When I misted my tank, it created a tiny puddle in that area and melted the bottom patch of HC that was on it. The patch itself is fine, but whatever was below the level of the puddle was dead..
BTW, will you be investing in an aquarium fan since summers coming up?