... you are still required to use Chlorine with the system per their directions. Yes, you do use less, but still required to use chlorine.
You don't use less chlorine compared to properly maintaining the spa with chlorine alone. It's only if you don't maintain the spa properly and allow biofilms to form when doing chlorine-only that you could create extra chlorine demand. That is, Aqua Finesse can insure against improper chlorine maintenance, but it doesn't reduce the amount of chlorine needed to oxidize bather waste because Aqua Finesse does not contain oxidizers or enzymes. So people who use too little chlorine because of any claims that less chlorine is needed can have that chlorine level get too low. Those who use the spa more frequently and have an ozonator basically have ozone doing most of the oxidation and is why the people who have had the most success with Aqua Finesse are those that have ozonators. The proper way to view Aqua Finesse is as an (expensive) increment to a regular chlorine regimen. If it provides perceived value, then that's fine, but it's not a chlorine substitute nor a chlorine reducer compared to a properly maintained chlorine-only spa.
This long thread discussion about Aqua Finesse includes posts from a U.S. representative of the company and some users who like it and some who don't. There are quite a few other threads and posts on that and other forums. The claim from the manufacturer of 80% lower chlorine use only occurs when compared to out-of-control chlorine-only spas with biofilm problems or
when you don't count the Aqua Finesse Trichlor pucks/tabs as part of the chlorine usage (see the
MSDS from
this page for such spa tabs to see that they are Trichlor). You can certainly add less chlorine (remember to include the Trichlor tabs in your count of how much chlorine you are adding), but it won't maintain a level if you don't add enough (and don't have an ozonator) with the result of your soaking in your own sweat and urine. I look at Aqua Finesse in a similar vein as Nature2 in that they are extra-cost insurance to prevent runaway bacterial growth if the sanitizer level gets too low. Some of the other main benefits can also be accomplished through a combination of Trichlor pucks/tabs in a special slow feeder, baking soda to raise the TA destroyed by the acidity of Trichlor, and a pH buffer such as a phosphate buffer (reduces calcium hardness as well) which minimize the amount of maintenance (though with some side effects like rising CYA). Or instead of a phosphate buffer one can use a boric acid product such as
ProTeam® Gentle Spa which also moisturizes and feels silkier, but should be used with a less acidic chlorine source (i.e. Dichlor or bleach).
