I just recently created my own basic DWC system. A 12 gal HomeDepot storage filled with water (also mixed with this nutrients https://www.amazon.com/General-Hydroponics-MaxiGro-Gardening-2-2-Pound/dp/B00NQANQAC). Beneath this small grow light (https://www.amazon.com/Lovebay-Adjustable-Gooseneck-Hydroponics-Greenhouse/dp/B074GR1KRT/ref=sr_1_3?s=lawn-garden&ie=UTF8&qid=1516303106&sr=1-3&keywords=growlight); I am really tight on space. Water level is just below the net cup; barely touching it. Room temp is around 65-70F.

When I created this set, I was skeptical about myself so I bought lettuce seedlings for cheap at my local Home Depot store. I thinned the seedlings, cleaned the soil, and put it on a net cup (roots hanging down) filled with hydroton.

Here are the pictures now, https://imgur.com/a/pkYte . Both the leaves and the stems seem really weak, and they curled up a little bit. I haven't considered pH to my hydroponics set yet (is this the main issue?). So if you guys have any advice, or suggestions that would be greatly appreciated!

EDIT: After a few hours, it looked something like this. https://imgur.com/a/mVMBG

EDIT: Thanks for all the feedback! I will wait a few days, hopefully it will get better. Meanwhile, I have another batch that I grow from seeds ready to be transplanted. Hopefully they're gonna be stronger than this homedepot seedlings.