Glad you got some good smoke. From the looks of it, it seems your might not have made it to the end with those leaves going bad.
When you say 300W are you saying 300 actual watts or 300 comparable watts?
How many fans did you have going? I'm finding the more fans, the less problems.
You need to look for different soil, that MG is hard to gauge. Never know when you're going to get a 'nute explosion. My local feed and grain store started selling Fox Farms soil, too much demand to not cash in. I went to the nursery the other day and saw they carry something called Golden Triangle Recipe 420. I wonder what that's for, huh? I got a big bag of it and going to do an unplanned grow just to see how good the stuff is.
Well, happy puffing.