Raenon...That's an interesting take. I'm not sure how you would set up your valves to keep vapor from leaking out the hose, or being to hard to pull on. I guess you could use a powered valve with a button, but that's going to bring build price up. Functionally I'm trying to do this as easily as possible so that most of the money can be spent on the casing. (Wanna use spare parts as much as possible so it doesn't hurt at bad when I mess stuff up.) Plus if it's easy to build it'd be easy to fix/replace parts.
@Hova
Either I didn't understand you or you didn't understand me. With a multiple feed system each hose could have its own flavor. Get your friends together and start passing hoses. Yes, we all COULD sit around and share our 510's or whatever, and we do, just like we used to sit around and smoke analogs. However, we also used to sit around and hookah quite a bit and there is a different "vibe?" you get when using the hookah. I am just trying to see if I can create a system that gives that vibe without using traditional tobacco. That's all. Plus I've seen lots of people and posts asking about one. Thought maybe I could help some people out.