Nute burn or calcium deficiency? *PIC INCLUDED*

Picture:

http://imageshack.us/photo/my-images/705/img20120518200054.jpg/

Strain is Emerald Kush, but my Super Lemon Haze is having the exact same problem. FOr some reason my Nirvana White Widows are looking great, and they're all being fed the same nutrient solution.

All are 4 weeks into flower. They smell great, but hte leaves look like shit. I'm growing in 2 gallon smart pots, 50% peat moss 50% perlite, sensi bloom A+B. I check, my PH is always between 6-7 when watering, and last run I found runoff to be PH 6.2.

I'm pretty sure this is either over feeding, calcium deficiency, or an mg def. Thoughts? I'll post pics of the SLH if it'll help diagnose.

Check into phosphorus def. Different strains use nutes differently.

Thanks for the suggestion. I'm checking it out. I would have guessed that feeding 1200ppm over sensi A+B would have fulfilled the phosphorus requirements. By the way, this started about a week ago with lots of rust colored spots on the fan leaves.

Spots can be calcium.. Not familiar with using Sensi.

I do generally use RO water when watering. My tap water has PH of over 8 and wreaks of chlorine. I'll put in some dolomite lime tomorrow.

Anybody else have insight to offer? I'll be feeding some of this:
http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?productId=203192761&storeId=10051&langId=-1&catalogId=10053&ci_src=14110944&ci_sku=203192761&cm_mmc=shopping-_-googlebase-_-D28X-_-203192761

I hope this does the trick and that there's no more damage :/

I use RO EC 0.0 and I mix old (48 hr) tap water to buffer this to EC 0.2. If you leave it to air out the chlorine will evaporate as a gas. My tap water is EC 0.45. This helps with Mg & Ca or u could use mono nutrients

http://www.420magazine.com/forums/frequently-asked-questions/81266-cannabis-plant-pest-problem-solver-pictorial.html

here ya go man should help!