Brown spots in flowering

Hey guys,
I'm in need of some advice, I'm growing a few white widow plants and they have been flowering for 3 weeks now, in the past 2 weeks they have developed brown/rust colored spots growing interiorly outward on the top fan leaves. The grow set up is small and personal, it's hydroponic drip system, using a cfl light. Temperature is usually 75-80, and humidity averaging out to 43%. The pH is consistently kept at neutral, and I'm at ~550ppm.
I also use fox farm hydro nutrients, but I never use the full amount that they say just for precautionary purposes. I tried looking up the issue in Greg Green's grow bible and no solutions. I originally thought it was a calcium deficiency, but as I do more research it could be over/under watering or nutrient burn or a number problems.If any one can steer me in the right direction it will jibe greatly appreciated.

First rule of this forum. It is EXTREMELY hard to give people advice without any pictures.

Calcium def

Haha right on, rookie mistake. Here's a pic from today.

Guess is calcium..as stated.

Hydroponic with a consistent neutral pH ?

Yea the pH is usually good, I use the pH indicator so I keep it looking yellow/green color. Any suggestion on how to make up for the calcium def?

Yes. Add cal/mag supplement. Or a teaspoon of epsom salts in a gallon of water is better than nothing.

I love how people are so quick to shout out a nutrient deficiency....Plus, you're obviously good about the ph, and that's the reason plants tend to suffer(ph imbalance causing a lockout), not because you're withholding nutrient.

If anything, I'd say you're probably over doing it somewhere in your nkp, your primary nutrients. And also, it does look a little over watered. Your original gut feeling is exactly what I would agree with. Cal-mag is a micro nutrient, important, yes, but a lack of it will seldom produce these results you show.