Check with your water department. Hubby works for ours, and brought the large, fire type hose home to do it. It does take a while even in that, but you should be swimming by night, or the next morning... I don't know how they do it. Also, cost is about $2/ 1000 gallons of water here... I think... So it really doesn't add up to much.
Lastly, where did you get it & does it have a flat bottom or go deeper in the middle?