I've assembled my tank (coke bottle) but am a bit worried about the 'softness' of the Tygon. I'm scared it will tie itself up in knots.

I've tried the stiff tube supplied with the UAT but it is a bit too stiff.

I'm thinking of using the stiff 4mm tube. This seems ideal but won't fit on the barb on the orbit clunk. I'm considering using 4mm tube and pushing it into a short length of tygon (it's a tight fit) and gluing with cyano. The tygon can then be pushed onto the clunk.

Is this ok or is there a better way of doing it?