Try feeding 8 parts chlorine per part of ammonia. If you want to remove 80 mg/l ammonia you need to apply 640 mg/l of chlorine. 1 % soluiton of chlorine is equal to 10,000 mg/l. If you want to know exactly how much to feed, volume of water to be treated and % of available chlorine is needed (if liquid is used). This is just a starting point because other materials can consume chlorine.

Bob Whitworth

The following is a quote from EPA's Nitrogen Control Manual:

"The utilities director's recommendation for other considering full nitrogen control by breakpoint chlorination can be summarized in one word --'don't'. "

It is not a stable reaction.  If you use elemental chlorine you will likely need to add alkalinity to ensure a complete reaction.  If you use hypochlorite you won't.

Clifford White's Handbook of Chlorination would be your best source of information.

Woodie