I'm using Vinyl tubing so I dunno... I just make sure the tubing is the same size as the Acrylic tube ends on the reservior. To get the Vinyl over the Acrylic, just run the first inch or so of Vinyl tube under hot water for about two minutes. This softens it up and allows it to stretch over the Acrylic tube MUCH better. Also, I tapered the tip of the Acrylic tubes to allow it to slip on easy.
Hope that helps.