Help!!.. Leaves Turning Yellow Then Brown

Hey guys for the past couple weeks, some of the leaves near the bottom of my plants have been turning yellow, then brown and dying off.. I up'ed there nutrients thinking it was because they were nitrogen deficient or had a similiar deficiency.. But it hasn't helped.. I'm starting to think that it's that they aren't getting enough light, and thats why it's happening to the lower leaves.. Here's some pics (Sorry if there a little dark).. Thanks in advance for your help.. And if more information is needed please let me know..

Pics of the whole plants and if no light on em they get used up and dropped.

There 5 Great White Shark.. And I'm just waiting on a 1000w HPS Grow Light Kit to come in.. I think it's from lack of light penetration to bottom of the plants, I'm going to lollipop them anyway, but I just want to make sure that there isn't a deficiency of some sort. Thanks in advance guys..

Sorry for any bad camera shots..

looking really good! it looks like a natural process of older leaves fading away. GL

those plants will def benifit from some serious lolipoing(looks like you could chop off the bottom 8"), gorgeous plants tho man, GWS has always interested me

Thanks for the responses guys .. I can't wait till I get the 1000 Watter in.. Im gonna transplant them into 15 Gal pots.. And throw 4 of the 5 of them into flower and then keep the other for some clones.. I think im gonna wait till i get the 1000 watter in to put them into flower.. I have some new nutes to.. I was using Tetrahydroponics BC line.. But i picked up some General Hydroponics Flora Series.. And AD Bud Candy.. What other AD additives should I get?.. Or will BudCandy be enough?

(I was thinking of getting this)

Cool.I was just gonna mention larger pots. I run veg nutes first 2 weeks of flowering. Indica will get twice as tall, sativa 3x and hybrid a mix.

It says on Greenhouse that they finish in 9 weeks, and based on the leaves i'd say its 60%/40%.. Indica/Sativa.. So they are definitley are gonna stretch a decent amount.. I hope I don't run out of room in my tent lol.. I may have to start tying them down..

Has anyone used the Hobbyist bundle would it be worth purchasing?