Leaves Dying off?? Help

What is your experience level? (first timer, novice, experienced...)
---First time---
Your Equipment:
.1) Type and wattage of lights. (MH, HPS, CFL's, tube fluorescents, LED's)- 250w
mh
.2) Distance from tops? 12 inches
.3) Reflector type? (cool tube set-up, bat wing, enclosed reflector, bare
bulb...) batwing
.4) Is there a consistent fresh air supply?- not constant but close
.5) Do you have an exhaust fan and a circulation fan?- no exhaust yes
circulation
.6) What are the bulb wattages, kelvin ratings, and schedule? -16 day 8 night
Your medium:
.7) Specific brand and type of soil, (coco, peat based soilless...) and anything
you've added to it. (vermiculite, perlite, worm castings...) FF Ocean Forest

.8) Size of container.
.9) Did you use peat pucks (or similar) to root clones or germinate seedlings?
Seedlings
Your nutrients and water:
10) Source of water? (tap, bottled or filtered) What's it's ph before
adjusting?- Spring Water
11) Method of checking water ph. (ph pen, test strips, aquarium test kit...)
test strips and meter
12) Method of adjusting water ph. (phosphoric acid, white vinegar, hydrated
lime, PH Up...) - ph up and ph down -
13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per
gallon) and current feeding schedule. -floralux started kit feed once every 3
days 1/2 recomended since problems started -
14) How often are you watering between feedings, and how much per watering?-
water just enough so soils moist-
15) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...)
no additives
16) Are your ph levels stable, or do they fluctuate? -PH is stable-
17) What is your ingoing water's ph? ...your runoff ph? -ingoing is about 6.5
runoff about the same 6.25-6.75
18) Do you foliar feed? If so, with what, how often, and at what time do you
spray?
- havent -
Your growroom:
19) Indoors or outdoors? -indoors-
20) What size of closet, room or hut? - room is probly 10 by 8
21) What are the temps and humidity levels while lights are on? ...With lights
off?-rh stays about 55 lights on 45 lights off -
22) Have you seen signs of insects in the growroom? - no but i saw one leaf that
looked chewed but never seen a bug-
Your strain:
23) What strain are you growing? (Indica dominate or Sativa dom?) - indica dom-
24) From seeds or clones? -from seed-
25) Is this an autoflower strain? -no-
__________ Ok so the problem is that some of my leaves start looking dry then
they start to brown up and get yellow spots around the brown. I changed my water
because it had a ph of 8 or higher, and switched to spring water about a week
ago. My leaves are still getting brown spots and turn yellow and curl up and die
over a few days. I have been trying everything to stop it and nothings working.
I'm pretty sure its not nute burn salt buildup because I have flushed them and
been giving minimal ferts. I have looked everywhere online I can and every sign
I have points to a nute defficany ( kinda looks like a mag deff) but I have
taken the steps to fix it with no results I really need help guys check out
these pics and please reply. :) Any input would help I'm stumped and don't want
to see them die :( --Look at these pics and please tell me what u think -- the leaves start like in the picture and then get worse and curl up until there's no more color in the leaf