There is one misleading statement in that, though the whole item does seem biased towards selling hydrogen-peroxide.
The chlorine-donors used in swimming pools do not break down to irritant chloramines. The chlorine-donor itself, or gaseous chlorine used in some professional swimming-pools, is not an irritant, because the dilution is so great. (It should be about 4, no more than 6, ppm: by comparison tap-water chlorine concentration is normally 2ppm. This in a properly-managed swimming-pool; not an ornamental pond.)
As that "amine" root suggests, they are the products of the chlorine reacting with the muck on bathers' bodies - perspiration, urine, perhaps some cosmetics or sun-block cremes.
A static pool like that in Washington will inevitably vegetate unless fitted with constant filtering, pH regulation (that is very important), disinfecting and algaecide dosing. Swimming-pool algaecides include copper sulphate. Hydrogen-peroxide and chlorine-donors are disinfectants, less efficient at killing plants unless in heavy doses.
The acidity regulation is important to help the other additives works properly, and to help reduce calcite scale from hard water. I don't know if Washington's water is hard or soft.
