Growth slowed

Looks like a little to many ppms. My leaves were half starting to curl like that and I backed the light up a couple inches.

Honestly, for a CFL grow I'm pretty impressed with the output on these sour D's! You're correct on both counts - you do have some tip burn which would be indicative of too heavy a nute regimen. But that canoeing in the leaves says heat burn to me as well. Not surprising at this stage with your CFL's so close to the tops. Sour D's an 8-10 week strain so realistically this may be less of a problem than you'd think at week 8 of flower. I'd suggest you start backing off whatever nute regimen you're on now regardless. I'm not a huge proponent of flushing the medium pre-chop but in soil and coco grows I do usually do it to some extent. I don't think this plant would suffer from a nice rinse of the medium at this stage. Not sure there's much you can do about the light burn issues. You can certainly back the light off a bit but CFL's really aren't going to provide much to the plant from higher elevations. You'll probably end up with some torched fans and toasty buds but they should still smoke nonetheless. Good luck with it dude, she should be fine to the chop!

That looks like heat burn and nute burn at this stage is not uncommon... looks ok...maybe too much nitrogen. Good luck ✌️🏼❤️🌱