Please HELP first grow and major plant problems!!! Pictures included!!!!

Hi all and thanks for your help!

My fan leaves are dying. However new branches and leaves still growing. Plants are 7 weeks old and I just switched to 12/12 lighting about a week ago.

I want to provide as much detail about the grow as possible. If I am leaving anything out please let me know.

Strains = Juicy Fuit, Cocolate Chunk, Shishkaberry, white widow, strawberry cough, og kush, and permafrost

Lights = 3 - 1000 watt MH/HPS swithable ballasts with 8" Magnum air cooled refectors.

Pots = 7 gallons

Soil = FoxFarms Ocean Forrest

Nutrients = FoxFarm Line - Big Bloom, Grow Big, and Tiger Bloom with Open Seseme, Beastie Bloomz and Cha Ching

Environment. Day temp 78-81 Degrees Night temp 70-72 Degrees. Relative humidity around 40%

PH and PPM feedings- PH 6.7 from drain water. always check before watering and 6.5-6.8. I have not gone over 1000ppm on the feedings and feed every other watering. Watering as needed. checking with fingers a few inches down and when feels dry I water.

CO2 - I am using a natural gas co2 generator and keeping the ppm between 1000 and 1500ppm

Origionally I thought this might be a phosphorus deficiency or possibly mg deficiency so I gave some Tiger Bloom and some Open Seseme for the macro and micro nutrients. I didnt notice any change after 4 days so I thought it may be a salt buildup and blocking out nutes. So Two days ago I flushed with clearex. about 2 gallons per plant watered slowly and drain water was dumped. I am not sure what the problem is or how to fix it.

PLEASE HELP!!!!

Thanks again and Happy Growing!!!!!

wow shitty shitty......

sounds like everything should be clicking...

i'd say after everything.. let it ride for a bit.. if new growth is still going fine..

any significant growth last couple of days?

Somebody will probably correct me, but that looks like classic nute burn. I agree with corum, let that flush work its magic.

Yes The new leaves seem to be coming in fine and and branches still growing.

i agree with assasin, deff looks like nute burn, flush nd it should recover

it will be fine, did you start in those pots? or did you transplant your way up?

either way 7 gallons is a big pot your plants focusing on its roots so its eating alot and everything it can find and those fox farm products are strong, cut back on the nutes and see what happens. remember that soil has enough nutes for 30 days so if your transplanting every time think of it as adding nutes for a few weeks then start up your nutes slowly.

Just a thought. I just brought in 6 new clones and have not given them any nutes at all. They are showing the same signs. I have transplants from 5 inch pots to 1 gallon to 7 gallon. Could it be my air or water. I am using tap but it sits.out for a couple of days before watering. Also cause I am using co2 and keeping the levels at 1000-1500ppm I am not bringing in a ton of fresh air to keep levels optimal.

idk man its a weed...let your water sit out for 48+ hours open container style......this will let the shit out and make sure you check your ph. if so its not the water.

your air? just use the proper cfm fan...i dont have those expensive fans but i do have 2 home depot 6 inch 250cfm fans for my area which is 4 x 4 x 7 high

use this calculator...http://cheaphydroponics.com/Merchant2/wattcalc.htm

i have never used CO2 but maybe its causing the issue, you said it yourself your not bringing in enough fresh air.

just a thought. if your clones are having the same problems and they havent been receiving any nutes, it possibly could b a bug prob. don wrry to much about it, but jus something to look into in case things don get better.