phototron converted to deep water culture unit and i need help

I am a beginning grower i have a 5' phototron that i have modified into a deep water culture unit(bubbleponics). there is a total of 6-54 watt flourescent bulbs, 6-24 watt flourescent bulbs, and 2-100 watt equivalent full spectrum daytime cfl's. I basically took shower flooring and cut it in to the shape of the inside of the phototron and cut 5-3" diameter holes in it. I have a 6" airstone, a 8" bubble wand and a 12" bubble strip all connected to a 100 gallon 5 watt air pump with 2 air nozzles and a 10 gallon 3 watt air pump with one nozzle that is attached to the 12" airstone. all airstones are placed under 3 gallons of water and dyna grow vegatative grow nutrients currently at half strength. my growing substrate is hydroton clay grow rocks, in 3" net pots. i also have placed three 6" fans on the inside. my problem is that my plants are 3 weeks old and two leaves at the bottom are completely white and the set of leaves above them are yellowing out leaving dark green veins and burning at the tips. the inside of my phototron stays about 80 degrees farenheit so i don't think its heat stress. i have plenty of pics let me know if more are needed. Any feedback would be Highly appreciated.

what ph? ppm? or ec? are the roots getting into the water enough? what are the temps of the water? in the cabinet?

i try to keep the ph at in between 5.2 and 6.0. i have to lower the ph once a day because it rises. the water level is about 1" above the bottom of the net pot.the water temperature is about 70 degrees.i dont have a tds meter yet but im going to get one soon. i'm basically using a fish tank ph reader with the colored liquids.

I'm using old tron unit. Lights had shorted out so I removed them and removed basin section, put in Rubber Maid pan with 3 holes (1 is service hole) other 2 for plants. I use autoflower now but have grown regular. I keep water just at 3/4 over roots, keep bubbler on, run two 75-w CFL, mylar surrounding inside of unit. Tron is great for autoflower low-ryder plants. I use Flora series but with the autos, only using bloom formula at 1/8 tsp per gal and only after plants show sex which current plant did at 21 days. My current grow is at 53 days and I just flushed 3 days ago and she's ready to harvest but I'm going to wait for 60 days. I ran lights 18/6 from start but just started another plant and plan to do 20/4 for it, so I went ahead and switched to 20/4 as of last night. My lights are hangn from top and can be raised and lowered as needed. Tron is great for stealth and short plants and I love the autoflower plants. I have a flat heating panel that stand vertical outside the unit. I don't worry too much about ph unless. One time I had a little bit of drooping and added about 1/8 tsp epsom salts to water, perked right up. I love my Tron for DWC.