That's what i used too. 20' of 3/8th o.d. copper tubing. I think it was $26 at Home Depot. Hose clamps hold on tubing that i slid over the ends of the copper. Another hose clamp holds the garden hose adapter on the 2' of input tubing. Then i run the garden hose from my laundry sink in the other room. The wife gave me a dirty look when she saw the setup, but I think we're alright. It took about 25 gallons of water to cool my 6 gallons of wort to 70 degrees. More than i expected. Maybe i'll make a pre chiller sometime.