by Gabe Ergler
Silica Spots – The other white spot
October 9, 2018
Clear Water Stain Shower Door
Hardness or Silica?

Hardness or Silica?

A common concern from most the homeowners I speak with is that “ugly white film” around their house. The white build-up in question can typically be found on shower doors, appliances, glassware, faucets, etc. Most often the culprit is calcium and magnesium, commonly known as hardness. Hardness can easily be treated with a softener. However, in some cases the problem persists even after softening. If that’s the situation you are experiencing you probably have Silica Spots.

Silicon Dioxide or Silica (SIO2);

is an oxide of the element silicon which is the second most abundant element found on earth. Silica is present in all natural water supplies in some form. Certain foods such as, strawberries, avocados, onions, root vegetables, wheat, and oat, contain silica. It can also be found in nature in sand, sandstone, quartz, flint, agate, and granite. Studies indicate that silica has health benefits and is needed for bone, cartilage, hair, and nail growth and it can be found in many supplements. Other studies show that Silica has no nutritional value. In either case, it does not appear that silica is harmful to the human body. Because silica is not found to be harmful it is unregulated by the EPA (Environmental Protection Agency).

In a water supply, silica can exist in a dissolved, particulate or a colloidal form;

A colloid is a very fine suspended particle that does not readily settle. In high concentrations it can form hard white scale deposits. Treatment for silica depends on the form it’s in. It may be possible to remove with a simple filtration process if it’s in a particulate form. If it’s in a colloidal form it may require some chemical addition such as magnesium salts which then need to be followed by filtration or a reverse osmosis (RO) system. If you suspect silica is present in your water supply, there’s an easy way to test the scaling. Wipe the affected area with white vinegar. If the vinegar removes the scale or film, the problem is probably hardness. If vinegar does not clean the area the you likely have a silica spots problem.

Needless to say, removal of silica spots isn’t as easy at appears. A salt based softener will not treat silica and the problem will remain even if the water is soft. Because a salt based softener won’t work you will need a treatment designed to handle silica. Our ICS system with PolyHalt® treats both hardness and silica and is highly recommended to protect the down-stream flow and your appliances including, water heaters, dishwashers, washing machine, ice makers, etc. ICS systems are small, convenient, easy to install, and easy to maintain. For more information on PolyHalt® and other water treatment options visit our website at

More really Good Information:

Ever wonder what hard water really is? Check our this Cascadian Clear blog post: Hard Water Defined

You likely noticed this blog does not discuss soft water, for that you will need to see our Cascadian Clear blog post Soft Water Defined.

Ever have someone test your soft water only to have them tell your your water is hard when you know it’s soft? Check out this Cascadian Clear blog post  Why Does Soft Water Test Hard?

If you wonder what a hardness test actually tell you please see our Cascadian Clear blog post: What Does a Hardness Test really tell us?

If you’d like to know more about chemical treatment of hard water see Cascadian Clear blog post: What is PolyHalt® and How Does It Work?

Do you have a salt-based softener but still have problems with spots on your glassware, shower doors and windows? Check out this Cascadian Clear blog post: Silica – The other white spot


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