5900S Neutralizer Operation & Maintenance Manual
Page 22
www.cleanwaterstore.com
Rev 110117
When to Use Calcite Blends
If the water pH is less than 6.0, Calcite alone may not be enough to bring the pH up to the
desired range of 7.0 to 7.8. In this case, a blend of Calcite and Magnesium Oxide (sold as
Corosex or FloMag brand). should be used.
Calcite is a calcium media consisting of calcium carbonate and will raise the pH slowly. Calcite
will not raise the pH much over 7.2.
Corosex/FloMag is a natural mineral media consisting of magnesium oxide. It reacts much
faster and raises the pH much higher than Calcite alone.
Corosex is almost never used alone as it will raise the pH too high and, in some cases, will over‐
correct and create a highly basic (high pH) condition. It can also cement together like concrete
in the neutralizer tank if you add too much and there is not sufficient backwash.
For most residential well applications, a 90% Calcite and 10% Corosex is best.
However, in some cases an 80%/20% mix or even a 70%/30% is used. It is always better to
start with a 90%/10% mix at first as this solves most of low pH problems in the range of 4.5 to
5.9.
For a pH of 6.0 to 6.9 use Calcite alone.
For a pH of 5.0 to 6.0 use a blend of Calcite and Corosex usually 90% Calcite and 10% Corosex,
or more Corosex as needed if the pH is less than 5.0.
How to Mix and Use Calcite Blends
The Calcite and Corosex media is sold and shipped in separate boxes. It does not have to be
completely blended together to use as it will mix during the backwash and rinse cycles.
When you are adding the Calcite and Corosex it is better to blend it lightly in a 5‐gallon bucket
and then add it.
You can also add some Calcite and then add some Corosex as you are filling the tank. Do not fill
tank more than about 2/3rds full.
