Seachem 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 phr 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 r