When water is sent to a home or business, it can contain minerals like calcium and magnesium. Water hardness occurs when there’s a high concentration of minerals in the solution.
While hard water isn’t dangerous to drink, it typically tastes bad. Hard water also leads to soap scum, clogged pipes, ineffective showering, and skin irritation. There are several techniques that can help you reduce the hardness of water, the primary of which is using a water softener to remove the minerals.
Total dissolved solids (TDS) is a measurement that identifies all inorganic solids that have been dissolved in the water. While TDS measures the various types of ions that directly contribute to water hardness, it also considers other substances. For example, sodium is measured with TDS even though it doesn’t increase the hardness of water.
If you need to identify the total mineral content in water, it’s highly recommended that you use the TDS measurement. When you wish to determine water hardness, the TDS reading can help you roughly calculate how hard the water is. This guide takes an in-depth look at using the TDS test for hard water.
What Is a TDS Meter and How Does It Work?
To measure total dissolved solids, you’ll need to use a TDS meter. This type of meter is designed to measure the electrical conductivity of water, which refers to how strongly the solution resists electric current. Identifying the conductivity of water allows you to determine the concentration of total dissolved solids by making a simple conversion.
When rain falls to the ground, the minerals in the surrounding soil and rocks will pass through it. Once these minerals dissolve, they will remain in the water and cause the TDS measurement to increase. Rainwater is slightly acidic, which means that it will likely taste better after minerals have been introduced to it. Some of the minerals that are commonly found in water include sodium, calcium, and magnesium.
The concentration of dissolved minerals in water is generally higher in some locations than others. When water has a reading of 120 mg/L or higher, it will be considered hard. Water is very hard when the readings reach 180 mg/L or higher. The ideal range is between 80 to 100 mg/L. Keep in mind that TDS can also measure organic material from waste, leaves, and sewage.
If you wish to use a TDS meter to measure the concentration of dissolved solids, the device will tell you if the water contains any salts and minerals. You’ll be able to use the reading to determine if you should increase the solution’s conductivity. As touched upon previously, TDS is estimated based on the conductivity reading.
When you’re searching for the right TDS meter, you’ll have access to models that range from $50 to more than $1,000. The higher-priced models usually offer better precision and more features. If you select a basic meter, you may only be able to measure TDS. A more advanced model should also inform you of the water’s temperature and salinity.
If the meter tells you that the water has a high TDS level, this indicates that there’s a considerable amount of dissolved solids and minerals in the solution. Eventually, these minerals can cause scale buildup to occur in appliances and pipes, which can damage the materials.
When you use a TDS meter, you’ll receive a conductivity reading. High conductivity means that your water contains an elevated concentration of dissolved solids. When you place the meter into the water, it will emit a small electrical current, which is designed to track how well the current is conducted. This reading will be converted into a TDS measurement.
Before you use a TDS meter, it’s important to understand that it doesn’t directly measure contaminants. It won’t inform you if the water is healthy to drink. Even though you can use this meter to identify the concentration of dissolved solids, you won’t know what these solids are.
Let’s say that you receive a high TDS reading. There may be no harmful contaminants in the water. Minerals like calcium, potassium, and magnesium are healthy. However, they also cause TDS readings to spike. If you receive a low TDS level, your water could contain harmful contaminants like pesticides, lead, and pharmaceuticals. These contaminants aren’t picked up by a TDS meter.
Before you get started, there are some temperature considerations that you must account for. Ion conductivity depends on the temperature of the water. When the water temperature is high, ions will move faster, which will invariably cause the conductivity reading to increase.
Some TDS meters compensate for temperature by obtaining this reading alongside the conductivity. When calibrating your TDS meter, it’s a good idea to set it to the standard temperature of 77 degrees Fahrenheit.
Can a TDS Meter Be Used to Measure Water Hardness?
You may be wondering if a TDS meter can be used to measure water hardness. While it can give you a general idea of how hard the water is, it measures much more than hardness. Let’s say that the TDS meter provides you with a high reading. While there’s a good chance that the water is very hard, a high percentage of the TDS reading will be comprised of other substances. In this scenario, the TDS value will be much higher than the hardness one.
It’s also difficult to use this meter to determine how effective your water softener is. Because of how the water softening process works, the meter won’t properly capture it. Water softeners are ion-exchange devices that obtain magnesium and calcium ions. These ions are exchanged for sodium ones. Even though sodium doesn’t harden the water, it has the same electrical charge as hard minerals.
Why TDS and Hardness Are Not the Same
To understand why TDS meters won’t tell you how hard the water is, it’s important to consider the many components that make up total dissolved solids. If water doesn’t contain any dissolved solids, it’s considered deionized. This type of water will likely taste flat. It often has a low pH of around 5.5. If you consume deionized water regularly, you might experience acidosis, which can result in rapid breathing, confusion, and seizures.
Dissolved solids involve any salts, metals, minerals, anions, or cations that can break apart in the water. Total dissolved solids can include the following substances:
- Sulfates
- Chlorides
- Calcium
- Magnesium
- Sodium
- Bicarbonates
- Potassium
- Organic matter
Most dissolved solids are inorganic salts. In drinking water, TDS often comes from natural sources, industrial wastewater, chemicals from the treatment process, urban runoff, and sewage. You might also receive high TDS readings from issues like seawater intrusion, mineral springs, salt deposits, and carbonate deposits.
The total dissolved solids measurement represents the number of anions and cations in the water. Anions are negatively charged ions, while cations are positively charged ions. Even though a TDS reading provides you with a qualitative measurement of the dissolved ions in the water, it doesn’t give you any additional information. As touched upon previously, different types of dissolved solids have unique effects on TDS readings.
If the water consists of high sodium levels, you’ll likely receive elevated TDS readings. However, the water may not be hard. On the other hand, the presence of chloride and sulfate can increase hardness and the TDS concentration at the same time. TDS will only decrease if you remove minerals, contaminants, and dissolved solids from the water.
When you’re attempting to estimate the hardness of your water, you can calculate it by dividing the ppm measurement by 10. Your TDS meter should automatically display a ppm reading. Once you divide it by 10, you’ll have a somewhat accurate hardness value. This value may be off by around two to three French degrees of hardness.
Limitations of Using TDS for Water Softener Evaluation
TDS also has several limitations when it comes to measuring the effectiveness of a water softener. A water softener is a type of device that’s capable of removing hard minerals from the water that’s sent to your home. This system can reduce hardness by removing minerals like magnesium, calcium, and iron. By keeping your water soft, you’ll be able to prevent the following issues:
- Chalky films on glasses and dishes
- Damage to appliances that use water
- Clogged pipes
- Leaky faucets
- Scale buildup
- Mineral deposits
- Faded colors on clothing
- Dry hair and skin after you take a shower
Water softeners are designed to prevent heavy minerals from flowing through the water or binding to it. Once you soften the water in your home, you’ll benefit from softer clothes, cleaner glasses, better-tasting water, and smoother hair.
While there are numerous types of water softeners available to you, nearly all of them use the same process to reduce hardness, which is ion exchange. As mentioned previously, the ion exchange process occurs when hard minerals like calcium and magnesium are substituted for sodium and potassium, neither of which increases hardness.
If you use a conventional water softener, water will move through a tank that contains a thick bed of resin beads. These beads are saturated with sodium, which allows for the exchange to take place. Once the hard minerals become attached to the beads, the sodium will enter the water. After the water exits the system, it will be soft.
Keep in mind that resin beds become saturated with hard minerals over time, which means that they will eventually need to be taken through a regeneration cycle. During regeneration, sodium-rich water will be placed in the system to effectively saturate the resin beads. There are many types of water softeners on the market, which include the following:
- Salt-based water softeners
- Dual-tank water softeners
- Salt-free water softeners
- Magnetic and electromagnetic water softeners
- Full filtration systems
- Polyphosphates
Salt-based water softeners are among the most commonly used systems. There are also numerous types of salt-based water softeners you can buy for your home. This system works by bringing heavy minerals into a resin and exchanging them with sodium. The main issue with this specific softener is that the resin will need to be recharged at least once every week. They’re also very large, which means that it will be difficult to store them in your home.
If you want a salt-based water softener for your home, there are a few portable options you should have access to. These systems also include a hose that allows you to connect it to a campground water supply or an outdoor faucet.
If you opt for a dual-tank water softener, you’ll receive two resin tanks. This salt-based softener is suitable for well water because of its ability to filter high concentrations of heavy minerals. The best aspect of a dual-tank water softener is that the second tank can be used after you place the first one in the regeneration cycle. There’s no downtime with this system, which means that you shouldn’t run out of softened water.
Salt-free water softeners don’t remove heavy mineral deposits. Instead, they are designed to effectively condition the water, which means that the minerals won’t build up on showerheads and faucets. Even though the minerals stay in the water, they can no longer function like normal.
Keep in mind that salt-free softeners usually come with a higher upfront cost. On the other hand, they don’t use electricity, which means that you should save money in the long run. These systems are typically smaller than salt-based ones, which means that they can effectively fit in smaller homes.
Once you soften the water in your home, you’ll likely receive the same TDS readings even though you’ve decreased the concentration of hard minerals. Sodium and potassium are just as effective at increasing TDS levels as calcium and magnesium. When you perform a TDS measurement, you can’t discern the effectiveness of your water softener.
As mentioned previously, the TDS level will always be considerably higher than the hardness one. In most cases, TDS consists of more contaminants than just hard minerals, which you won’t be able to account for when taking these measurements.
Proper Methods for Testing Water Hardness
There are several methods you can use to test water hardness, which include hardness test strips. Likely the fastest way to perform this test is with a clean and empty bottle. Make sure the bottle is around one-third full of water.
Before you place the cap on the bottle, add a few drops of any pure liquid soap at your disposal. Once it’s closed, you only need to shake the bottle for a few seconds. If you find that there aren’t many fluffy bubbles above the water, there’s a good chance that it’s hard. Your water could also contain a high concentration of hard minerals if it appears milky or cloudy.
If the water is soft, it will produce a lot of bubbles when you shake it. The water that rests below the bubbles should be clear as well. Before performing this test, keep in mind that many soaps are made with detergents, which means that they’ll lather even if you have hard water in your home. Your best option is to use a basic soap that’s free of perfumes, detergents, and dyes.
While the water bottle test is somewhat effective, it will only inform you if the water is hard or soft. To discern the level of hardness, you must perform a more sophisticated test. You can identify the level of hardness in your water by using a hard water kit, which includes a color chart and some test strips. These kits are available at most supermarkets and home improvement stores for $10 or under. Some companies also provide them for free upon request.
If you opt for the test kit method, fill a small glass with cold water, which you can take from your kitchen or bathroom sink. Place the test strip in the water for a few seconds before you remove it. If you decide to place the strip under running water, the results will likely be inaccurate. After you remove the strip from the water, it will begin to change color. Compare the final appearance with the kit’s color chart to identify the hardness of your home’s water supply.
Consider obtaining more advanced test kits if you’d like to perform a comprehensive water assessment. Online retailers and home improvement stores may also sell test kits that evaluate solutions for alkalinity, nitrates, pH, iron, and chlorine.
The most in-depth analysis can be obtained by sending a sample of your water to a third-party lab. They’ll be able to test your water for unique contaminants, such as bacteria and heavy metals. Keep in mind, however, that this type of water assessment usually isn’t necessary when testing hardness.
Some hardness test kits include numbers beside each color. You can match the number with a specific hardness, which will tell you how high the concentration of dissolved solids is. The average hardness in U.S. homes is around 13 grains, which is viewed as very hard. If your water comes back with a reading of 14 grains or higher, it will be extremely hard. The overall effects of hard water begin to occur at just seven grains of hardness.
If you begin to notice signs of hardness in your water, it’s highly recommended that you perform hardness testing. This type of testing is also useful if you’d like to determine how effective your water softener is. On the other hand, there are times when it’s best to take readings with TDS meters.
If you want to remove all contaminants from your water, obtaining the conductivity reading can be highly beneficial. You can also use the information from a TDS meter to determine if the methods you employ to treat water are effective. Place the TDS meter in the water before and after you treat it. Compare the differences to determine if your treatment has worked as intended.
Conclusion
TDS tests can help you identify the total concentration of dissolved solids in a sample of water. You can use this reading to make a rough estimate of the water hardness in your home. However, it might be more advantageous for you to use hardness test strips if you want to know the specific level of hardness. It’s important that you use the right testing method to obtain accurate results. If you’re looking for ways to maintain clean and healthy water in your home, consider using a combination of TDS meters, softeners, and hardness test kits.
Source link: https://sensorex.com/tds-test-for-hard-water/ by Joshua Samp at sensorex.com