dwc bucket system with res

I currently have a 4x4 tent with 600 HID doing a DWC. I would like to expand and get a 6x4 tent for flower and use my existing 4x4 for veg. I would be doing manifold training.

I would also like to do a bucket system with res since I will be running only one strain. 4 plants in veg and 4 in flower which would get 3'x3' in a 5 gallon bucket. Do you guys know where I could find some ideas on how to build that? Any suggestions for lights and vent?
I was thinking 4x 315 cmh.

I'd say that you should be able to grow some really nice trees with that setup. I run basically double the # of buckets(3 gal) on an 18 gal rez using a simple gravity drain system/air stones and a small pond pump to recirc fluid back to the buckets. I just built some stands for the buckets to give me a height difference to the rez and that creates plenty of circulation. I grow in my walkin closet so no help on venting-I run a pair of 4 lamp Vero arrays @320W/bar-it's plenty for the space you're working with. I'd think that 4 cmh's in that space would be damn bright.

I'm not sure what to tell you about building the RDWC, I've read about it but never done it. Google it, there are lots of diy articles.

As far as your lights and exhaust, the way to do it is to have the fan sucking air out of the light, and going to a place outside of the grow space for heat issues (if it's staying cold in your grow space you can just recirculate your exhaust or just have it shoot out of the tent.

The best way to do it is to have a closed exhaust system that sucks air in from outside of the tent, through ducting, through the light, and leaving through ducting outside of the tent. And have a second fan sucking through a carbon filter, blowing through ducting out of the tent (this will knock the smell down a bit, but won't likely remove it entirely).

If you get a powerful enough fan, you can hang your carbon filter on one side of your light and your fan on the other and do it that way. Either way you either need one really good fan or 2 decent ones. Inline fans of course. Make sure the cfm rating is right for your tent or you'll have it either too hot or too dry in there.