Any o-ring lubricant will work...you can get it anywere they sell plumbing stuff (ACE Hardware, Wal-Mart, Lowe's, Home Depot, etc.). Usually near the o-rings. It's not expensive $1-2 per tube and it should last a while. I think sometimes it's called plumbers lube or something...it'll say right on it that it's for use with o-rings though.