What Is Silica?
Silica is a hard, glassy mineral and one of the most abundant elements found in the Earth’s crust. Just like calcium, magnesium and other major minerals, silica is found in groundwater supplies at varying concentrations, depending on the surrounding rock. Continue reading to learn more about silica and the effects it can have on your water quality.
How Does Silica Get Into Drinking Water?
As water passes through the Earth, it dissolves silica from rocks and minerals. Because of this, most — if not all — water supplies contain some amount of dissolved silica. It’s also found in certain foods like oats, rice, strawberries and more.
Signs of Silica in Your Home
Silica in water leaves its mark in several ways in your home. For dishes and fixtures, through persistent white spots or buildup, as well as etching and scratching. For plumbing systems and water-using appliances, silica builds up in pipes and reduces heating and cooling efficiency and effectiveness, as well as restricting water flow. Silica in water can also leave your hair dry and brittle after washing, cause breakage and poor absorption of hair color.
Reactive vs. Colloidal Silica
There are two different forms of silica that end up in water: reactive silica and colloidal silica. Reactive silica is a very weak acid that dissolves in water, while colloidal silica has a glass-like structure that can damage surfaces, glassware and fixtures. While both forms of silica are harmless when ingested, they can also leave behind cloudy or milky spots on surfaces and fixtures, as well as white, chalky build-ups of minerals called scale.
| Reactive Silica | Colloidal Silica | |
|---|---|---|
| Common Signs/Issues | Can cause scale buildup | Can cause fouling in equipment, such as RO membranes |
| Removal | Ion exchange resin; reverse osmosis | Requires more advanced treatment, such as ultrafiltration or RO |
| Form | Dissolved in water as ions | Tiny, undissolved particles suspended in the water |
Removing Silica From Water
There are multiple treatment options for removing silica from water, on both residential and commercial levels, based on identifying what type(s) are found in your water. After determining this through a free water test, here are the solution options.
Ultrafiltration
Ultrafiltration systems have extremely fine membranes, giving them the ability to filter out solid matter on a microscopic level. Because colloidal silica is suspended in water, ultrafiltration is great for its removal. However, these systems cannot effectively remove reactive silica. A challenge of this silica removal option is being able to determine the type of silica in your water as there are not feasible testing options to determine silica type and particle size. For this reason, we recommend treatment options that either sequester the silica preventing etching or removing silica through a process of reverse osmosis.
Ion Exchange
Ion exchange water softener systems significantly reduce dissolved ions from water, making them perfect to deal with the negative charge of reactive silica. With a negative charge, anion resin is the required media. Occasionally, these systems will need additional crystalline salt to continue working, which is something Kinetico can help with/deliver to you.
Additionally, due to the constraints of testing, it is difficult to determine the silica type and whether or not ion exchange will be effective for the type of silica present in your water.
Reverse Osmosis
Reverse osmosis water purification systems have the advantage of removing both molecules and ions from water, effectively dealing with both reactive and colloidal silica in the process. At over 99% removal rates for all contaminants, RO is one the best methods of treating for silica while also providing you with the best water possible. This solution is ideal for drinking water quality. Some pre-treatment is still required for colloidal silica. RO systems also need annual maintenance and eventual membrane replacement, but Kinetico can advise on/help with this.
Sequestration
Silica sequestration systems do not use filtration, ion exchange or reverse osmosis to target silica but sequester the silica by using a sequestering agent to prevent etching and scale. These systems will require replenishment of the sequestering media over time which will vary depending on water use. Due to the fact that these systems introduce a sequestering agent to the water, they are not ideal systems for drinking water where high levels of purity are recommended.
Keep Your Water Palatable and Your Appliances Clean
If you think silica could be causing damage in your home, schedule a free water test with one of our water experts today. We’ll walk you through the best water treatment options for your home and budget.
