I used aquarium sealicone. Let it dry for a while and it worked for me. But I only had a small leak right at the top of the tube where it attached to the bulkhead. Good luck
A hose clamp wouldn't work, it plugs up into it not over the top.
But it's fine now...turns out that a little piece of plumbing tape slipped down in between the bulkhead and the hose causing it to leak. Woops