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 no ammonia removing product can 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.