Vacuum hose where ? for gauge install

Hello everyone

I got from a friend a vacuum gauge. My question is where i can find a hose for it?.Can someone help me with this because i tried and i connect it here : (picture)

Now i feel like my car lost his power...so where can i connect it safe?
(I have a cold air intake filter placed and there are 2 other hose without vacuum)

these are the 4 vacuum pipes :)

The one on the back of the manifold, where the throttle body bolts on, as shown in the photo above goes to the charcoal canister on my car.... I put the 'T' piece in a couple of inches back from the charcoal canister.
Not to sure if its 100% accurate taking the vacuum signal from there but my gauge works and the car still runs the same.

Thankyou ! I got it !