Can you grab a photo of your room pretty quick when you have a chance. What you would need for a DWC is a large rubbermaid tub tub with lid....(how about the tub you are using as a res??) and hang them in the large tub...they can all be intermixed no problem....then a few airstones (many as you can) and an air pump to drive them and your nute solution. (check out my thread on how I built mine) How long dimensions of the lids the are in?

I'd agree with going to a different technique...i seriously think this time your problem is that that your plants are too big for your system and are rootbound. They need more room and they are sqeezing each other out for oxygen and nutrition.

They look great but you CAN see them starting to have issues. Good luck.