problems with lower leaves during flowering (pics)

hey everyone, so with a friend we've been growing a plant for about 6 weeks right now shes in one and a bit weeks of flowering, we need small plants for small space. ever since shes been in flowering the lower leaves have been turning yellow and falling off.
the set up:
1 -42W Warm White
1 -24W Warm
1 -13Wwarm
1 -42WDaylight
12/12 schedule
water every 2-4 days with distilled water, with 1/2:1 miracle grow 10-15-10
in basic potting soil
good ventilation
temp at 80-82 day 60-65night

please tell me what im doing wrong to these girls or if this is just a natural cycle this strain could be goin through? please let me know if you guys can...i also checked the growFAQ inside and out and couldnt really find the answer im looking for. im thinking it may be nutes lock but even then i wouldnt know how to fix it nor would i know how to lower my ph if that was the case..which i dont knoe btw just cause the local stores decided to not have any more ph test kits in stock...anywhere!

I would cut back on the fertilizer every watering....the tips of your leaves look like they are begining to burn from excess fertilization. Try fertilizing only every other watering. Also, make sure you allow the soil to dry out really good between waterings. The bottom yellow leaf appears to me to be from over watering.... Overall it looks good though. Good luck, ~Outlaw~

I am pretty sure that the yellowing is a nitro deficiency. I would research it further... Macro-nutrients Nitrogen (N) is primary to plant growth. Plants convert nitrogen to make proteins essential to new cell growth. Nitrogen is mainly responsible for leaf and stem growth as well as overall size and vigor. Nitrogen moves easily to active young buds, shoots and leaves and slower to older leaves. Deficiency signs show first in older leaves. They turn a pale yellow and may die. New growth becomes weak and spindly. An abundance of nitrogen will cause soft, weak growth and even delay flower and fruit production if it is allowed to accumulate.

looks like a nitrogen dificiancy or over fertilizing. leach the soil with 3gallons of water per gallon of soil. flowering plants dont need nitrogen they need a moderat to high p,k and water when your soil is drying a light crust on top next time i'd sugest using coco fibers as ur substrate as it holds water,nutriants and air very well

ok so what can i add to neutralize all this crap thats goin on to her? what kind of nutes can i use? i was told to use epsom salts but i dunno please if you guys can let me know the best and cheapest remedy for her that wqould be great, im a total noob and have really really studied all of this but my first grow so i will learn for next time