Yellowing leaves while Flowering.. please help!

So I put my plant under 12/12 almost 2 weeks ago and everything has been going pretty well except starting several days ago I noticed some yellowing and discoloration on my top two fan leaves. It's steadily been getting worse and I have no idea what the problem is. For feeding, I've been alternating between molasses and Green-Lite Superbloom at half potency. My temps are good and I have a fan blowing on the plant 24/7. I'm using 3 cfl bulbs which are about 1.5 inches from the top of the plant. I gave it a little bat guano during the last molasses feeding but it didn't seem to help. If anybody has any ideas about what I can do to fix this, I'd really appreciate it. This is my first grow, and I've had a few problems but I've learned a lot from this forum and I thought I was doing everything right... damn!

if i were you i would only run light or no nutrient mixture to the water just straight water... especially about 3 weeks prior to ideal harvesting.. it more than likely could use higher dose of potassium... but i havnt really expierenced your problem for my self but i 've read alot of stuff on the web. and thats some of the stuff i've heard.

ALso there could be over watering will do it, having lamps to close to plant also, and like i said go easy on nutrients during budding cycle