I currently have a medical grade ozonator with oxygen tank, etc.
However, for about a year I used a unit similar to your (200 to 400 mgs/hr). I'd say ozonating a gallon for 45 minutes to an hour would be good to burn off any chlorine and charge it up with ozone. Ozone water is very easy to work with and will not burn at all (extra hyrdogen atoms is what causes burning - but ozone just adds an oxygen atom). It's great for soaking fruits and vegis in, or washing down your counters, etc. Also, be sure to drink it immediately after ozonating since this will give you therepuetic value as well.