when theres water actually in the bong, the smoke is pulled through it filtering/cooling it, with just ice it would just cool it. ...and who doesnt want that satisfying chugggg a lug you get from the water! :rasta:
ohhhjh nm, i thought you were asking something else...
Make an aqualung out of cut up 2 liters, and use a pool or hot tub or whatever, as the water container, and fill her up, and rip, I don't know, im fresh out of the ovan as in baked right now so PEACE,