Total Dissolved Solids and TDS Meter Guide

Total dissolved solids (TDS) in water refer to the total amount of organic and inorganic solids. The amount of TDS in water can affect the water’s taste and appearance. Measuring TDS is a great place to start if you’re concerned about water quality.

What are total dissolved solids, and where do they originate?

Dissolved solids in water are substances other than the pure hydrogen and oxygen (H2O) elements that compose the water. These dissolved solids include minerals, salts, metals, organic waste, and suspended solids like wood pulp.

Water’s most common total dissolved solids are calcium, magnesium, sodium, potassium, chloride, sulfate, bicarbonates, and fluoride. TDS can also include zinc, copper, lead, aluminum, iron, and arsenic. Chlorine, pesticides, and herbicides are also dissolved substances. These contaminants are primarily sourced from agricultural runoff, surface runoff, or the natural weathering of rocks and soils.

The contaminants that make up TDS concentrations will differ depending on the water source and the surrounding environment. Think of TDS as a cumulative measurement of everything lurking in your water. Knowing your TDS level can help you determine if further investigation is needed. To fully understand the contaminants in your water, you must do more comprehensive water testing.

What TDS level is considered safe?

The amount of total dissolved solids in the water can make drinking water unsafe.

The average TDS level of United States tap water is 170-400 parts per million (ppm). According to the Environmental Protection Agency (EPA), the maximum TDS level should not exceed 500 ppm. High TDS levels are between 300 and 500 ppm. Water with high TDS levels may contain harmful contaminants that could be hazardous if consumed.

Measurements above 1000 ppm are considered unsafe, and water with a TDS level of 2000 ppm or more will require more advanced filtration.

Can drinking high TDS water cause health problems?

Not all TDS are considered harmful. Even filtered, purified water will have some TDS. A TDS measurement can include beneficial minerals that your body needs, so eliminating all TDS in your water is not necessarily what you want to do.

Contaminants like lead, copper, and pesticides can pose serious health risks. Lead can damage the brain and nervous system, pesticides have been linked to chronic illnesses, and copper can cause nausea and other issues. These contaminants will be accounted for in the TDS measurement, but more detailed water quality testing is required to identify them.

Knowledge is power, so you should test your water to learn more about its contents and find the best water filtration solution for your unique needs.

Why is measuring TDS important?

TDS affects the quality of your water and can also impact the condition of your water-using appliances. Measuring total dissolved solids will help you better understand what is happening with your water.

Here’s why monitoring TDS is essential:

• Sore Senses: High TDS can make your water taste or smell odd. It can taste bitter or metallic and may even have an earthy or chemical-like scent. This can affect your drinking and eating habits. No one wants to drink nasty-tasting water or strange-tasting pasta that has been cooked in crappy water. It may also make cleaning a hassle because of the spots it will leave on dishes, and the residue can remain in your kitchen sink.
• Health Hazards: A higher TDS may not be necessarily dangerous, but if the TDS substances are lead or copper, this could pose a health risk. Lead can damage the nervous system, and copper causes nausea.
• Failing Filters: When filters have to reduce high levels of TDS, they will wear out faster. This can lead to more frequent filter changes and higher costs.
• Ailing Appliances: Hard water results from higher concentrations of calcium and magnesium, which can lead to scale build-up in pipes and appliances. If not appropriately addressed, this can lead to expensive repairs and shortened lifespans of dishwashers and washing machines.

How to Measure TDS

There are three ways to measure TDS in water:

1. Easy: Using a TDS meter, which measures TDS instantly.
2. Intermediate: Involves filtering 50 mL of water through filter paper into an evaporating dish, letting the residue dry thoroughly, then weighing the dish again. The measurements can then be calculated using the formula TDS (mg/L) = (A – B) x 1000/Water Sample (ml)
3. Advanced: Using an electric conductivity meter, you can convert a stable reading using the formula TDS(mg/L) = 0.6.7 x Conductivity (µS/cm).

What is a TDS meter and how does it work?

A TDS meter is a simple handheld device that can effectively measure concentrations of dissolved ions in water. The unit of measurement for TDS meters is ppm. For example, if you dip the meter into a glass of water and it reads 100 ppm, this means that out of one million particles, there are 100 dissolved solids in the water.

A TDS tester is intended to measure the presence of TDS in the water; it will not help you identify the dissolved solids. TDS meters are an excellent tool for detecting issues requiring more detailed water testing.

When shopping for a TDS meter, here are a few things you should look for:

• High accuracy
• Suitable range (0-9999 ppm)
• Automatic Temperature Compensation (ATC)
• Clear display
• Optimal Battery Life
• Auto-shutoff
• Waterproof

Filters Fast variety of TDS meters to measure the level of TDS in tap water and filtered water.

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How to interpret TDS levels

Once you get a reading on your TDS meter, how do you know what it means? Here’s a quick breakdown of TDS level ranges:

• Below 250 ppm: This is considered low. The water may taste flat or lack the appropriate amount of beneficial minerals like calcium and magnesium.
• 300-500 ppm: The usual TDS range for drinking water. Water with this TDS level should contain enough beneficial minerals and taste pleasant.
• 600-900 ppm: TDS levels in this range are considered high and may indicate a water quality issue.
• 1,000-2,000 ppm: Considered unsafe for drinking.
• Above 2,000 ppm: Above typical safety standards and may require a specialized filter.

This quick-reference TDS chart can help you decide how to proceed when used in conjunction with a TDS meter.

Does low TDS water taste flat?

Water with low TDS may be flat or bland because it lacks the dissolved minerals that give it a natural flavor. If water filtering leads to tasteless water, you may want to explore a remineralization filter to improve the taste.

What to do if your water’s TDS level is above the recommended limit

If your TDS reading is above 500 ppm, have no fear; there are steps that you can take to ensure that your water is safe.

Addressing High TDS

Test Your Water

The first step after measuring TDS should always be to test your water. Testing your water with a water quality test kit or having it professionally tested will give you detailed results about what is in it. Once you know what contaminants are in your water, you can better determine which filtration system is right for you.

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Invest in a Water Filtration System

The following filtration methods are effective at reducing total dissolved solids in water:

Reverse Osmosis is highly effective at dissolving impurities in water. This water filtration system utilizes multiple filters and a semipermeable membrane to remove many contaminants.

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Water Softeners are an ideal solution if high TDS is due to an overabundance of magnesium and calcium minerals, also known as hard water. Through ion exchange, water softening systems replace hardness minerals with sodium or potassium ions. A water softener can help prevent scale build-up and improve appliance lifespan and cleaning results.

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Activated carbon filters can resolve water quality issues related to chlorine taste, odor, and some organic compounds. However, they do not target all dissolved solids.

The distillation process will remove most dissolved solids and contaminants.

Deionization involves the exchange of ions found in dissolved solids for hydrogen and hydroxide ions. This process will produce water that has little to no TDS level. Deionisation requires a special system and filters.

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How to calculate rejection rate

If you have a filtration system, TDS testers help determine the most accurate time to replace your filters.

For example, most reverse osmosis membranes have 2-5 years of lifespan. Because this filter has a vague lifespan, you cannot easily judge when to change it.

Using a TDS meter, you calculate the rejection rate of the reverse osmosis membrane and determine precisely when to replace the filters and the membrane. The TDS meter reassures consumers by confirming that they should replace the filters as soon as they reach capacity.

To calculate the rejection rate, you measure the TDS level of the filtered water processed through the RO system (RO product water), subtract it from the TDS level of the unfiltered tap water that bypasses the RO system (pre-RO feed water), divide the result by the pre-RO feed water, and multiply by 100.

For example, if the TDS level of the filtered water is 25 ppm and the TDS level of the unfiltered water is 350 ppm, this is what the equation would look like:

350ppm – 25ppm = 325ppm

325ppm / 350ppm = 0.92

0.92 x 100 = 92% Rejection rate

How does TDS affect water filter maintenance?

Water filtration is key to reducing dissolved solids in water. However, water with high TDS can wear out and clog filters quickly. That’s why it’s essential to understand what is in your water and how to treat it.

Measuring your water’s TDS level regularly can help you track water quality changes and ensure the filters work correctly. Changing your filters and maintaining your system regularly also helps ensure the best possible water quality.

Tackling TDS

We can help you fix water quality problems caused by TDS. You can find a variety of TDS meters and water quality test kits for purchase. Once you’ve figured out what contaminants to target, we can help you find the best water filtration system that fits your unique needs. Filters Fast’s contact number is 866-438-3458, or you can email Filters Fast at [email protected].

Related Blogs:

• What is TDS in Water?
• Is Drinking Filtered Water Good For You?
• ZeroWater Filter Guide: Remove Contaminants Safely!