i have a kids sippy cup filled with ona.. not very big, maybe idk, 8 oz's or so.. i run my air pump hose down the straw in teh sippy cup, and turn the air pump on high so that it's blowing the air down the straw and up through the ona.. when ever i re-fill it, about every two weeks or so, i can smell a strong ona smell...
i also have a carbon filter though, but it only runs when the lights are on..