On my "T" I use a small 4" black cable tie (Lowes) like a hose clamp to secure it to the nipple. It's not necessary because it's pretty snug anyway and we're not talking pressure here, but the insurance keeps me from pacing at night. On the burp holes, you have to slice the airline (which is oversize) diagonally to a sharp tip (think of the tip of a hypodermic needle) so that you can grab it on the underside with a pair of pliers and pull it through that hole. It's very snug and almost stupid-proof. The airline sits 2-3" into the vessel so there's enough there for security.