There are some anti-chlorine product comes with ammonia detoxification function. The most popular is Seachem Prime with a high concentration of 5ml treating 200-liters of water. In addition, Fritz Aquatics ACCR Ammonia Chlorine & Chloramine Remover Water Conditioner also has a dual function that is to remove chlorine, chloramine and can also detox ammonia. Both of these products are very safe to use even in overdose. Available on-line at Shopee, Lazada and the aquarium e-shop of your choice.