[Tainan]

We have a 3 stage also and a RO on top of that. Wife still insists on boiling the water to remove any left-in chemicals.
We get the filters changed every 3 months or so. Water tested after to check results.
As to the local testing by the 'Water Department'...when I lived in Huntington Beach we could take samples of tap water to the Water Department anytime and they would run a full screen on it.

I was a home brewer and so was the chief of the Water Department. We had some mighty fine water there!

Tap water is one thing, but most people don't think about their shower water. The skin is the bodies largest organ and it absorbs whatever is in your water.
Shower filter anyone?

[daniel1212]

The skin is the bodies largest organ and it absorbs whatever is in your water.

I think this is an often made but incorrect statement.

How many times have you read that skin absorbs 60% of whatever is applied to it? Yet there is no evidence to support this figure. In practise, the skin will absorb anything from 0% to 100% of whatever contacts it but in general the primary function of the skin is to act as a barrier that prevents the intrusion of external materials. Cosmetic companies actually have to work hard to develop formulations that can be absorbed into the skin to deliver all the benefits the consumer expects. - http://www.thefactsabout.co.uk/content.asp?menuid=32&submenuid=117&pageid=117&menuname=How+do+moisturisers+work%3F&menu=sub

Also see: http://skeptics.stackexchange.com/questions/5415/are-minerals-chemicals-absorbed-through-your-skin-during-bathing

http://www.survivalistboards.com/showpost.php?p=5052498&postcount=27

http://www.newton.dep.anl.gov/askasci/gen06/gen06003.htm