vacuum transfer Q's

I have been reading about the wort wizard and the diy one. creating vacuum in a sealed system in the carboy to transfer from the Bk through the cfc and then into the carboy, well I have been thinking why bother with some water actuated venturi and not with a regular vacuum. I also seen a few posts with a medical pump and those seem to be a bit more expensive, the last few weeks I have been making upgrades and I am about broke. first I was thinking that it could be a hazard in a glass carboy if too much negative pressure was created. causing the glass to break and then I have been pondering a few other vacuum's. My best ideas are using a shark wich is a hand held vacuum and then I thought about a air mattress pump that my mom has for camping. like this. http://www.kmart.com/shc/s/p_10151_...003a&ci_src=14110944&ci_sku=089W465415110001P

I know that it can both suck and blow, with not a lot of pressure in either direction/ I am going to try the shark tomorrow with a better bottle just to see if it makes it cave in. if it does not I would think it is ok for use with glass. I am also going to find a kmart that has one of these and if it does not work atleast I have 30 days to get my money back..

also for you medical pump users what psi/hg do you run at?

i would love to have feedback on this!

A little update, the most the shark would pull up hill is about 3' vertically. on a flat surface (single tier configuration) it was a success, with the carboy sitting on the same level so a slight uphill pull. with the carboy on the floor and the chiller and carboy table height, with normal gravity it took 3:44 to move 2 gallons, with the vacuum assist it took 1:33 to move the same volume. i do not have a vacuum gauge so I am not sure of the exact pressure, I regulated the suction with my hand so the shark was not at 100%. I did take a video, have to find my usb cable for my phone so I can put it on youtube

I was pondering vacuum possibilities this morning and found this thread. Did your video ever make it public? I'd like to see it in action. Also, what size tubing were you using for the x-fer?