Yellow leaves - not sure which deficiency?

I'm not sure whether this is a boron, calcium or potassium deficiency. The plant is about 2.weeks into flowering. A few days ago I gave it a well good dosing of mag salts diluted if that helps. Feed back appreciated. Thanks

Post more pictures, of whole plant. Looks pretty good to me actually.

https://www.rollitup.org/attachments/marijuana-plant-problems/2876676d1383159175-sick-girls-4-leavedeficiencies.jpg

https://www.rollitup.org/attachments/marijuana-plant-problems/2876677d1383159176-sick-girls-4-nutrient_deficiency_flowchart.jpg

From the second chart (flow chart) what you mentioned and the picture you provided it may be a boron deficiency. The yellowing of the fresh inner growth at base of young leaves. She looks happy though.

Not so much on the calcium (at least from what the photo you posted shows). Does not look like potassium to be either. Light burn possibly?

maybe getting root bound.. and is very sensitive to any type of nutes at this point..

I think the plant looks great. I've gotten those tiny discolored tips more than once and it never amounts to anything. I always thought it was minor nute burn but really don't know for sure. In any case it never caused me any problems. The small amount of yellow in your first pic is not unusual either and I would ignore it unless it got worse. A couple waterings including cal-mag won't hurt, and may give your plant a darker green color overall. Just my opinion.

Looks rootbound to me. Any droopy leaves? Its hard to tell from my phone. Greenish yellow new growth is normal when they stretch but solid yellow isn't a good sign. if you have used calmag recently I doubt that it is a straight up deficiency of any sort. Perhaps the ph is causing causing deficiency of some sort, but don't compound nutrients if you are keeping up with feedings. I'd say check the soil ph, if it's normal, pull up those roots and take a look. i generally wait to use nutes until im POSITIVE its not anything else (ph, temp, humidity, roots, bugs, stress).

Thanks for the advice. It's definitely not root bound as I only recently upgraded pot sizes. I will buy a pH test kit and see if maybe that's causing any lock out.