Amguard safely, rapidly and efficiently removes toxic free ammonia. It is safe to use during tank cycling and is ideal for treating unexpected emergency situations. Amguard reacts with FREE ammonia within minutes and does not alter pH. Ammonia can exist in two forms: free and Ionized. It is only the free form that is toxic. Traditional ammonia test kits convert all ammonia to free ammonia by raising pH to 12-14; at this pH amguard cannot function and thus a false Positive Reading will result. Use ammonia Alert or Multitest: free & total ammonia to directly monitor levels of free ammonia. Amguard also removes chlorine and chloramines.