Clubsub - Dive Centre
411 Ash Bank Rd, Werrington, Stoke-on-Trent, Staffordshire ST9 0JP
£4 for a 3l or 4l tank. don't know about bigger sizes sorry. I will ask asap.
they stock some best fitting acc's, & a few gun bags, along with jsb etc pellets, not cheap to buy by the way