By Rehan Iqbal
Have you noticed white residue in your shower, bathtubs, and on your dishes? Are you experiencing low water pressure? If you’ve answered yes to either of these questions, you may have a problem with hard water. The most common cause for this is an accumulation of calcium in your household plumbing.
The next question has to be: How do I remove calcium from water?
This article is all about hard water, most specifically water with excessive calcium, and how to deal with it. To gain a full understanding of what we’re talking about, I’ll start by discussing hard water and calcium in water.
Hard Water vs Soft Water
The primary difference between hard and soft water is the PH, or acidity level. A neutral PH for water, being neither acidic nor alkaline, is 7PH. As PH increases, the water becomes less acidic or alkaline. Alkaline water is called soft water.
On the other side of the spectrum, acidic hard water has a PH less than 7. Naturally occurring rainwater tends toward being acidic, measuring around 5PH. When this water falls to the ground, minerals are dissolved into the water, hardening it by increasing the PH.
Alkaline minerals, like calcium and magnesium are actually healthy, but leave a residue that we often call limescale. This can be seen as a white scale in our appliances like water heaters, washing machines, and dishwashers. It will often leave a white, chalky residue on our dishes or appear as spots on our clothes after being washed.
In many areas, excessive minerals, like calcium, is a problem. We can even notice that the water has white “milky” appearance. The limescale that results will end up collecting in our water pipes and fixtures, like water heaters, causing blockages that can reduce water pressure and even cause pipes to burst.
To summarize the effects of hard water, here’s what we need to know:
To treat hard water, dissolved minerals need to be removed in order to reduce the PH, thereby softening the water. Since calcium is the most common culprit, this is what we will be addressing. However, removing all hard metals from water is accomplished using the same methods.
Softening the water will reduce the presence of all hard minerals, not just calcium.
Tips for Removing Calcium From Water
There are simple ways to remove calcium from the water in your home, often using common household ingredients.
Adding an acid, like vinegar to water will increase the acidity, thereby softening the water. A reaction between minerals, like calcium, and the acidic vinegar neutralizes it by bonding with hydrogen.
Adding vinegar to your dishwater will soften it and prevent staining. While this is a simple cost-effective means of removing calcium from water, it is limited in its application. You cannot safely and effectively add an acid to the water supplying your home in this way.
Adding vinegar to water from the faucet will soften it at the pint of use. This will not, however, prevent the buildup of limescale in your pipes and appliances.
Table salt, sodium chloride (NaCl) is a common water softener. When salt is added to hard water, the chlorine gas separates and sodium bonds with the hard minerals. This is another relatively cheap way to remove calcium from water.
The only issue with using salt to remove calcium from water is that will usually have a salty taste. There are water filtration methods that use controlled dosages of salt that remove minerals, like calcium, without making the water taste too salty.
Distilling water is a natural process. It is how rainwater is created. By heating water, it evaporates to form water vapor. When the water is passed through a condenser, it cools and the vapor reverts back to a liquid form.
As the water is heated to boil it, only water molecules evaporate, heavier minerals remain behind. This means that when the water is condensed back into a liquid, only pure water remains. Distillation, not only removes calcium, but all heavy metals, bacteria, and other harmful contaminants.
Distilling water is time consuming and will not provide instant soft water on demand. It is, however, completely safe, using no chemicals. It does not affect the taste of the water, like salt or some other chemical methods of removing calcium from water.
Calcium hydroxide is a fairly common method of increasing PH in the preparation of food products and purifying water.
Since handling calcium hydroxide is hazardous, this practice is not used for domestic water. It is predominantly used on an industrial scale, where safety procedures are closely monitored.
A common stage of household water filtration uses an ion-exchange resin. The resin or beads are contained in a tank. As water passes through the tank, heavy metal ions, like calcium and magnesium, are exchanged for soft ions with a higher PH.
This is another safe and easy method of removing calcium from water. While not too expensive, the resin will need to be replaced when saturated with hard metal ions. This involves the cost of replacing the media and a maintenance procedure which is usually quite simple.
Electronic Water Softeners
Technically, the term electronic water softener, while commonly used, is incorrect. This is because these electronic devices don’t actually remove calcium and other hard minerals from the water. They merely alter the chemistry of these minerals.
A more accurate definition would be an electronic descaler or water conditioner.
By using electro magnetic force (EMF) an electronic descaler changes the ionic structure of minerals, like calcium. This means that dissolved minerals in the water become suspended, inhibiting their ability to cling to surfaces, like the inside of your pipes, fixtures, and appliances.
The calcium remains in the water but passes through freely, instead of causing a buildup which blocks pipes and causes staining.
The device is usually a small box that is easily retrofitted to the existing plumbing in your home. It has two wires that are connected to an electrical outlet. Electronic water conditioners are generally installed at the point of entry, where the main water supply enters your home.
This ensures that all the water supplying the home is safe from hard metals. It is mainly used to protect the pipes and fixtures from limescale buildup.
There are many types of water filters that are designed to soften the water by removing hard minerals like calcium.
These filtration systems come in all shapes and sizes. This could be inexpensive water filter pitchers and countertop water filters, or whole house reverse osmosis systems. Not all water filers soften water. It can be one of several stages of water filtration.
Simple filter cartridges, used for pitchers and countertop water filters will often contain an ion-exchange resin, or water softening media. As the water passes through the filter, hard minerals are removed and replaced with soft ions.