Excellent link lilnaugrim, you can see how they tend to nip away at the webbing, leaving the rays alone. Very species specific, I learned something today, TY!
PP is a great thing when used properly, make sure the treatment tank is squeaky clean, as it is an oxidizing agent that will not discriminate between bacteria on the fish, and ambient bacteria in the substrate, as well as the filter. You want it to do its thing on the fish, not your deco's & hardware.
By law municipal water suppliers do have to publish a yearly report, here's the one for my water;
The maximum chlorine level detected for the year was 1.02ppm, legally they can bring it up to 4.0ppm. Minimum was 0.30, a pretty low dose, almost nothing to worry about. Looking as Seachem's site, Prime in a regular dose will neutralize 4mg/l chloramine, & 5mg/l chlorine, mg/l being close enough to ppm for aquatic use. I chose Prime due to it being such a commonly used product, and my water report because it's what I get to work with. You can find most any of them online thanks to Google, city & state then Water Quality Report.
Bottom line is the disinfectants in your water supply are an oxidizing agent, working much the same as PP, but no doubt PP will work better. Tap water is quick, easy & cheap, PP is a more controllable treatment. I've got a link somewhere to mixing it from powder, from an angel forum, I'll have to dig that out as I should be heading to work, Mondays, ugh.