well, after reading this thread for the first time, i'm surprised to see so many people using these things! Hehe, I've just built my second one, my first worked okay, just too small, had to fill all the time. This new one works rather well, it's made from 4" pvc, similar to the guy's picture above, except mine uses a watercooler jug. the noise was a big issue, as my fiance and I sleep close enough to hear any loud noises, she hated the delta, so watercooling was my solution to that. I used some green pads to slow the water and noise as well, works excellently, had to make a screen so that the "loosened" green pads didn't fall apart and into the reservoir, so far so good on that. I used a ground sprinkler hose attachment, cost 96cents at Home Depot, and bought a 1/16th drill bit to cut more holes. I submersed a pump in the reservoir, put an 80mm fan on the front (fits perfect on 4" pvc sanitary tee openings, have to sand the fan a little bit) and my temps are ALWAYS room temp or 2 to 3 degrees lower (water temp that is) I use an inline thermometer to monitor the water temp going into the cpu block and one to monitor the temp of the input line to the bong, and one more on the outlet of the bong. I'd recommend this type of setup to anyone, it's easy to build, and from seeing that "sideline water jug" setup, i think i might like that even more, might have to borrow the idea.