Tops Yellowing

I just Cut back my lights and the tops are starting to yellow. I am using the Fox Farm Series nutrients and Roots organics Soil-less blend 707, and Humboldt's own Bushmaster. I applied my first application of flowering nutes 3 days ago and for some reason i am getting yellowing in my leaves as they are shooting out of the top of the plant. They are not burning but just yellowing is this normal?...I was trying to go lite on the nutes since the bushmaster is so hot and used 1 tsp of grow instead of 3 u think this could be our problem?

It's your first plant right? They do this...almost positive there's no problem.

Yeah, just switched to 12\12, and started using a 300-500ppm nutrient solution as well. Tops are coming up very light lime green, however growing has increased. I also have the leaves drooping, however I think I can now say that is overwatering. I flushed it with 500mL of water to help drain off excess nutrients.

Anyone know of a different problem I might be experiencing:
- light lime green new growth two leaf sets back
- drooping new growth, yet old growth still seems ok?

Pics would be best for both of you.

As for you Maxor... In all my experience, lime green new growth seems to happen when it comes out super fast. As long as it greens up later then its not a problem. In fact when I see the bright green/yellow new growth, I know the plant is healthy and growing. As for the drooping new growth, might be a PH problem. I noticed you said you didnt have a way to check your ph in another post.