ChlorGuard™ safely, rapidly and efficiently removes toxic chlorine. Chlorine is commonly used in many municipal water sources to disinfect tap water. Chlorine is toxic to all aquatic life and should be removed before use of such water. ChlorGuard™ should be used whenever doing a water change or adding water. Be aware that many municipalities treat water with chloramines rather than chlorine. ChlorGuard™ will not remove chloramines. Check with your municipality water provider if you are uncertain which is used in your area. If chloramines are used, then use Prime® or Safe™ instead. ChlorGuard™ is an econmical alternative to Prime® when the additional benefits of Prime® are not needed.