Question

how chlorine bleach works

Answer 1

Clorox bleach is 52000 ppm Sodium Hypochlorite. It can be neutralized with commercial dechlorinators.

Chloramine (NH2Cl) is often used to treat water because it doesn't evaporate as quickly as chlorine. Sodium thiosulfate is a common dechlorinator. It breaks the NH-Cl bond. 0.3 lb of sodium thiosulfate dissolved in 34 ounces of water will treat 10,000 gallons of water. The ammonia component of chloramine is then used by plants or bacteria inside the tank. Some products such as Amquel will convert the freed ammonia to harmless ammonium ion. Since the concentration of chlorine/chloramine is limited by the fed to 4 ppm, there is not much concern about having too much ammonia in the tank after the use of a dechlorinator (less than 0.5 ppm with 60% water change). There is no need to add a dechlorinator when changing less than 10% of the water.

Amqel or equivalent is beneficial only if transporting fish over a long distance, because it will render fish waste into harmless ammonium ions.

It is possible to purchase sodium thiosulphate at swimming pool supply stores. The cost is between $1 to $3 per lbs, depending on volume. Ask for sodium thiosulfate prismatic rice crystals, or Halogen Reducer.