Leaves dying one week into budding

Hey,
I was growing for two years with no problems, but about a year and a half ago every time i try to bud the leaves turn yellow and die. They seem to be light sensitive the leaves on the sides or down low stay nice and green. Iâ??ve tried moving my light further away, new bulbs, new room, and i have cleaned everything. I have thrips and have got rid of them on the leaves but they are still in the medium and i cant seem to get rid of them. just wanted to see if anyone had any ideas.

HYDROPONICS/Aero Ponics/Coco/Soiless/
-Soiless
How long has this problem been going on?
-1.5 years
Are you growing in a PVC grow tent? (example: Hydrohut or any other non brand tents)
-No
What system are you running? (DWC? Ebb flow? Aero? Water Farm? Flood Tables? and so on...)
-Ebb grow
What STRAIN are you growing?
-AK
What was the establishing technique? (Were the seed or clone?)
-Clone
How tall are the plants?
-2 feet
What PHASE are the plants in? (seedling, vegetative or flower)
-Flower
What substrate/medium are you using?(Hydroton, RockWool etc.)
-Hydrotron
What is the Water temperature?
-70f
What color are your roots? White? Brown? Are your roots slimy?
-White/Brown....not slimy
What Nutrient's are you using?(If growing soiless)
-GH
How much of each nutrient are you using with how much water?
-recommended amount by GH..... mixed one at a time
How often are you feeding? (If using soiless)
-Morning and night for the first two weeks then and then just morning
How often are you giving nutrients? (If using soiless)
-New nuts every few weeks
If flowering, when did you switch over to using Bloom nutrients?
-Second week
What is the TDS/EC/PPM you are using
-GH recombined
What is the pH of the "Tank"?
-5.8 to 6.1
How often are you testing your pH/PPM/EC/TDS?
- Every 24hr
Are you sure your calibration is correct on your equipment?
-Yes
How often do you clean your system: example: Flush out water replace with clean water and nutrients?
-7 to 10 days
What size bulb are you using?
- 1000w hps
How old is the bulbs you are using?
-New
What is the distance to the canopy?
- Start 3ft away and move closer
What is your RH Factor(Relative Humidity)?
-RH 40%
What is the canopy temperature?
-78f
What is the Day/Night Temp? (Include fluctuation range)
-78day/ 70night
What is the current Air Flow? (cfm etc.)
-800cfm
Is the fan blowing directly at plants?
-no
Is your water HARD or SOFT?
-Just right
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?
-Tap
If using tap water, what is the ppm/EC/TDS of the water right out of the tap?
-7.8PH 80ppm
Has plant been recently pruned, cloned off of or pinched?
-No
Have any pest chemicals been used? If so, What and When?
Are plant's infected with pest's.
-thrips

ph is a bit high for flowering. in hydroton i flower with a ph of 5.3-5.5. also what are you doing to control your thrip problem and are you sure it is thrips and not aphids? either bug needs to be addressed with Pyrethrum based product and not hot shots no pest strips. no pest strips do not have the chemical to kill thrips or aphids. they are mainly used for spider mites and black flys and gnats. if you still have bugs you should fog your room. doktor doom has a fogger and spray and foxfarm makes a great organic insecticide made with prethrum which is derived from flowers in a spray bottle. bugs sucking out the nitrogen and a bad ph will cause this to happen.

If you have NGW tube in your room please check out this thread it sounds like your problem. I scratched my head for a year myself trying to figure it out.

http://boards.cannabis.com/indoor-gr...ml#post2145305