ClorAm-X isn't approved by the FDA. They say it is not under their jurisdiction. There is a difference. It does look like a good product and inexpensive too.

The ultimate water test is daphnia (water fleas). Any chemical you use for water conditioning, FDA approved or not, should be tested to see if daphnia can live in aged water so treated. If you can produce a growing population of daphnia it is a good treatment. If not, then reconsider. Taking out chlorine, chloramine, and ammonia is only one aspect. Also keep in mind that most of the harmful chemicals are simply bound up and not actually removed.

My water source had loads of other stuff like hydrocarbons and PCB's. Daphnia never had a chance. Now with my water filter in place they thrive. Removal is better than adding stuff.