Direct Answer to Removing Chlorine & Chloramines
So I just got a call back from a chemist at API regarding their Tap Water Conditioner, and how it works.
You can put tap water directly into an aquarium, and add the Conditioner afterward. You can also put it in at the same time, or beforehand. The conditioner just needs to be combined with the tap water near the time when it is being added to the aquarium. The Conditioner works instantly.
A few other interesting points:
In free-standing tap water, chlorine dissipates into the air in 12-72 hours. Chloramines take a 1-2 weeks. So even free-standing water should be treated, as chloramines are probably still present (along with any heavy metals).
Chloramines are a combination of chlorine, nitrogen and ammonia. Municipalities use chloramines instead of, or in addition to, chlorine. Chlorine is less stable, and may combine with certain organic compounds, resulting in carcinogens. Chloramines are more commonly used where weather is warmer. Over the past 16 years or so, the amount of chlorine and chloramines has risen in tap water in modern municipal water systems.
The Tap Water Conditioner binds with chlorine, forming harmless acidic compounds. Chloramines are broken up, resulting in acids and sulfuric compounds. (As bacteria break down the compounds, more acid is created.) Heavy metals are encapsulated. Water changes are necessary because over time, aquarium water will become more acidic and encapsulated heavy metals will accumulate in a tank.
I was very impressed that a professional from API called me back, and did so quite quickly. I was able to talk directly to somebody who works at the molecular level with this stuff. Not only was it interesting, it was very helpful!