A buddy of mine found some used tanks at a closed dive shop. He's thinking about getting a few to save $ in the long run by not having to rent tanks. While I agree, the effort required to haul it to the LDS to get filled, then to the boat, then back home makes the tank rental seem reasonable. Do most of you guys own your own tanks or just rent them? Seems it would take alot of diving before you hit the break even point.