FOR THE LOVE OF MARY JANE HELP ME!!!! Medical Hydro grow.

So i like the community here but have always had a bad time getting help from people in this particular sub forum.
I am begging you peeps to repsond and bump this thread and help me out. Medical grower wityh paitnets and im getting soooo frustrated.



1)
2) Indoor
3) once to twice daily with Ro Water supplemented with calmag
4) rockwool
5) Veg

I have this problem on most of my plants after a few days. This is my 3rd grow with the same issue. Ive had the problem before and am at a loss to what it is. At first i thought ph too high but i have a blue lab meter and keep that pretty in check now. I can finish a whole crop and just trim the shit away but i know its affecting my overall weight on my girls.
Then i thought maybe a calmag problem because i use RO water but ive lately given a veyr hefty does of that as well.
I get this on some leaves all over and alot more near the bottom. Its only here and there spotchy but eventually the leaf dies form it.
Near the bottom of the plant the same type of thing happens but the leaves get very yellow first.

Could that be burn from the lamp your using, Theres allot of things that cause browning, it would be easyer to figure this out if you described how your set up works.

If its not the light i would think its potash

heres how you ask for info on a plant problem:

Begin Example:

symptom: whole plant wilted and lower leaves dying and dropping for past 2 days
date from seed: 4/20/2012
germination type: rockwool cube
strain: Blueberry Yum Yum Bagseed
grow type: DWC, 5 gallon bucket, 6 inch net pot with perlite surrounding rockwool cube
temp: ~90 daytime ~75 nighttime
relative humidity: ~50% daytime ~65% nighttime
nutrients: 2 tbls FF grow big, 2 tbls FF big bloom 1 tbls MG allpurpose 18-18-21 water soluble per gallon (1/2 FF label doseage, 1/4 Mg label doseage
water: plain tap water with low dissolved solids (less than 50ppm on average)
lights: ~200 watts CFL, and 4 foot flouro tubes mixed
photoperiod: 24/7 lights
ventilation: 50cfm extraction fan, ducted outside. intake is directly from outside air vent, with 10" oscillating fan on medium 2 feet from foliage
known pest problems: none
pest control measures: none

Details: while out of town, my DWC airpump failed, now my shit is almost dead wut do? wut do??

i got a new pump installed 2 days ago but they havent perked up! am i fucked???

End Example.

with this kind of data one can receive helpful information. an admittedly excellent picture of a single leaf (good job on the pic) but no info on the prevailing conditions that could cause the problem gives very little to go on.

lay down the data and im sure someboidy will be able to offer help.