please help?

this is my first grow.
it started out in that cashcrop 4.0 box. until i realized that its way too small, and i moved plants out of box into closet space.
for the most part, 6 weeks of vegetation went ok. but i unfortunately had to leave town for 2 1/2 weeks, at week 4'ish. i had made a bunch of nutrient solution for my friend who was house-sitting. and she kept the level up while i was gone. she had no knowledge to be able to do anything else really.
so towards the end of me being away. she emailed me and said that bottoms of the 3 plants are starting to wilt and brown. again,..too much to explain for her to be able to correct anything so....i just hoped i could repair when i got home.
so i removed a lot of dead leaves from bottom when i got back....did a flora-kleen flush, and made up new nutrients for beginning of blooming cycle.
that was a week ago...and conditions have worsened. the leaves seemed super dry...so i began to spray them with water once a day, no help. i added AN cal-mag to solution in hopes it would help, it didnt. i have removed so much dead stuff from the bottom that it looks very bare now. and im worried this problem will continue up to the rest of plants.
the top part of all 3 plants, look amazing. vibrant and green and healthy. buds started to form after 2 days of light cycle change.
my PH has been pretty normal i think. nute solution starts out at 6.0 - 6.1 and it dips down to 5.7 after about 24 hours. i will occasionally PHup it back to 6.0-6.1 range.

i took a bunch of pics,..all from today.

1) PICTURE OF PLANT *** VERY IMPORTANT *** - below
2) Growing indoor or outdoors - indoors / hydro / dwc
3) Watering schedule - umm i fill reservoir daily.
4) Growing Medium - clay pebbles in netpots
5) What stage of growth - 2 weeks into bloom

i use GH flora/micro/grow and some AN additives. bigbud,budcandy,rhinoskin,koolbloom.
ppm is about 1050.
there is two 2 inch air stones engulfed in the roots.
my lights are - LED 2 ufo style - 138W,about 10-12 inches from tops of plants.
i have a fan blowing 24 hrs/day

there is pic of roots. i feel like my reservoir is way too small for 3 plants. but i cant really seperate them now being so intertwined like that. big rectangle cake of roots.
any help is appreciated. at this point im kind of hoping it will just survive. and i can get what i can from them and.....try again.

You are going to have ph problems w/ those plants in that small of a tub. The roots need room. They look okay on top. As long as you have already taken clones, I don't see any reason not to finish them in a larger rez.

forgive my ignorance,...but how would i do that?
if i were to cut up the top of reservoir they are in now, in order to free them from the lid.
how would i get them back into another reservoir?
and what size would you recommend?

i havent taken clones. since this is my very first run...ive been trying to keep things as simple as possible. and i dont really have a location yet to start clones.
but i have more seeds that i bought, of this same strain - Bianca

Need more air in res. room temp maybe high need more air moment
i don't think roots will get much bigger then what you see you found out how big DWC can be lol

bigbud,budcandy,rhinoskin,koolbloom. check to find out if has organics or sugar in it
" Avoid anything "organic" in the nutrient water, that means extracts, vitamins, acids, and definitely no Carbohydrates (sugar). Organics feed brown slime algae as well as pythium "root rot". "

room temp is only 70-72.
i just read a post though about fresh air. and how lack of it will cause your plants to eat themselves. i think that may be a factor for me.
i know they havent got much fresh air at all,..cause its 40 degrees outside i have kept the only window nearby closed almost the whole time.
im gonna keep it wide open all day and see.

dude just get a bigger tote and place 1x4 down on new tote and close it in were no light gets in and add more air and another stone .you can get a tote twice that size and keep them in the lid they are in and make another lid to match up to new tote stting on wood planks

i will do this tomorrow. thanks a lot for the input guys.

10 gallon tote. was much easier than i thought duh.
i am also adding more ventilation to closet. intake from outside and exhaust through filter.

thanks again.

now thats what im talking about ,just got to use the imagination man