The Corosex Media is a special type of media that helps to neutralize the acidity of water, making it one of the simplest water pH correcting utilities available in the market today. You can mix the Corosex F with calcite to treat water with the pH as low as 4. Up-flow filters are recommended unless the water is under 5 grains hard. A minimum of 50% calcite is the recommended percentage to prevent cementing. Corosex Media can correct red water conditions too. It treats corrosive water, making it safer for daily usage. The non-corrosive conditioning is a result of acid-neutralizing properties of free carbon dioxide in water. Frequent backwashing is recommended to prevent possible cementing. Corosex is a reactive form of magnesium oxide-most effective for pH correction in places that have high-flow conditions.