Corosex® and Corosex II is a specially processed hard, bead-like magnesia, adapted for use in filters to neutralize acidity by increasing the pH value


By neutralizing the free carbon dioxide in water, Corosex can correct acidic water conditions and render it less corrosive. Corosex, being a highly reactive magnesium oxide, is used most effectively where pH correction is substantial or high flow conditions are in use. pH correction and media consumption are affected by a number of water chemical variables. Being soluble to acidity, Corosex will slowly dissolve and will need to be replenished periodically. On a per weight basis, magnesium oxide can neutralize five times more acidity than can calcium carbonate. This results in greatly reduced chemical usage for the same pH correction. Please note; under certain low flow conditions, Coresex may overcorrect and create a highly basic (high pH) condition. Under certain hardness conditions, pH correction can cause hardness minerals to precipitate out of solution, resulting in cementing or solidification of the Corosex mineral bed. Upflow service is generally recommended with hardness exceeding five grains per gallon. (Always use an in-line filter head of an upflow system to prevent plugging of the lower distribution screen.) As Corosex’s magnesium oxide neutralizes the water, it will increase hardness and a softener may become necessary after the neutralizing filter. Corosex can be effectively combined with Clack Calcite to combine the high flow neutralization properties of Corosex, along with the slower reacting low flow properties of Calcite, reducing potentially high basic properties due to overcorrection.

High degree of activity and speed of correction allowing high flow.
High capacity…less chemical usage.

Color: Brownish white
Bulk Density: 75 lbs./cu.ft.
Mesh Size: 6×16
Specific Gravity: 3.6 gm/cc
Effective size: 1.4mm
Uniformity Coefficient: 1.7
Composition: MgO 97% min.

Downflow service is generally satisfactory on waters with a hardness of less than five grains/gal. or where it’s combined with Calcite at least 50-50. Upflow service is generally recommended with hardness exceeding five grains/gal. to prevent cementing of the Corosex bed. Use distributors designed for upflow applications
*A gravel support bed is recommended
Water pH range: 4.5-6.0
Bed depth: 24-30 in.
Freebed: 50% of the bed depth (min.)
*Back was frequently to prevent possible cementing
Backwash rate: 10-12 gpm/sq.ft.
Service flow rate: 5-6 gpm/sq. ft. but may be modified to adapt to local conditions
Max usage: 100 mg/L


Service Flow Pressure Drop and Backwash Bed Expansion charts to be added later. Check back for updates.


Part No. A8011
Description: Corosex
Cu.Ft./Bag: ..66 (50 lbs.)
Wt./Cu.Ft.*: 75 lbs.
Bags/Pallet: 60
Weight/Pallet: 3050 lbs.
Pallet Dim. 48″x36″x50″

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Certified to NSF/ANSI Standard 60