What Is TDS In Water?

TDS, or Total Dissolved Solids, is the concentration of minerals, salts, and metals dissolved in your water, measured in milligrams per liter. It is also one of the most misread numbers in home water testing.

A handheld meter gives you a figure in seconds, but it will not tell you whether the water is safe to drink. So what is TDS in water actually measuring? Quantity, not danger. A reading of 400 could be harmless calcium, or something worse.

That distinction matters. High TDS water usually shows up as scale on your fixtures and a flat, metallic taste, not as a health risk. Knowing your number is useful. Knowing what is in it is what Rayne Water tests for.

What Is a Good TDS Level in Drinking Water?

Once you know what TDS is, the next question is what counts as normal. Most drinking water ranges from 50 to 500 mg/L. Anything under 300 mg/L is considered excellent, and TDS water levels above 1,000 mg/L become noticeably unpleasant to drink. Here is how the ranges break down.

If you live in Rayne’s service area, TDS is not an abstract number.  Colorado River water starts at under 50 mg/L at its source and reaches roughly 700 mg/L by the time it crosses into California, climbing to around 900 mg/L at the Mexican border. That places a major supply for Southern California, Arizona, and Nevada in the “Fair” band before it reaches a treatment plant, and above the EPA’s 500 mg/L secondary standard. This is why scale on fixtures is so common across the region.

Detecting Signs of Elevated TDS Levels

While water with Total Dissolved Solids (TDS) isn’t inherently harmful, high levels sometimes lead to unwanted health issues.

Here are common signs that your water’s TDS levels might be higher than ideal:

• Unusual Taste or Odor: If your water has a sharp, metallic taste or a salty flavor, it might be a sign of high mineral content.
• Mineral Buildup: Notice white or chalky scaling on your faucets, showerheads, and pipes? That’s a classic sign of hard water with high TDS, which can leave noticeable mineral deposits.
• Skin and Gut Issues: For those with sensitive skin, water high in TDS can exacerbate skin conditions like dryness or eczema. It might also cause digestive discomfort if you have a sensitive stomach.

Tips and Techniques for Managing TDS Levels

Keeping your water’s TDS levels in check involves a few steps:

• Regular Testing: Just like how you regularly check your car’s tire pressure, testing your water’s TDS is crucial for maintaining its quality. It helps you monitor dissolved minerals and organics, ensuring the water is healthy and appliance-friendly.
• Tailored Water Treatment: Depending on your specific TDS readings, treatments such as reverse osmosis or distillation can effectively remove excess minerals and contaminants.
• Effective Filtration Systems: Installing the right filtration system will improve your water’s taste and safety by reducing TDS levels.

Assessing TDS Levels: A Key Step in Water Quality Management

Testing your water’s TDS levels is an essential part of home maintenance.

The EPA sets a secondary standard of 500 mg/L for total dissolved solids, roughly equivalent to 500 ppm. It is worth understanding what that number does and does not mean. It is an aesthetic guideline covering taste, staining, and mineral deposits, not an enforceable health limit, and the EPA does not consider TDS at that level a risk to health. 

What it does signal is water likely to leave scale on fixtures, shorten appliance lifespan, and taste noticeably metallic or salty.

Addressing High TDS Concerns: Practical Solutions for Homeowners

If you find yourself grappling with high TDS:

• Explore Treatment Options: Choose appropriate treatments based on your water test results to reduce unwanted minerals.
• Install and Maintain Filtration Systems: Regularly maintaining your water filtration systems ensures they continue to reduce TDS effectively and keep your water safe.

Long-Term Benefits of TDS Management: Enhancing Health and Home Comfort

By managing your TDS levels, you’ll enjoy several long-term benefits:

• Better Tasting Water: Reducing high TDS can remove the unpleasant taste and odor from your water, making it fresher and more enjoyable to drink.
• Appliance Longevity: Protect your household appliances from scale buildup and efficiency loss, extending their lifespan.
• Potential Health Advantages: For those sensitive to high TDS, managing these levels can help avoid digestive issues and promote overall well-being.

In short, keeping an eye on TDS ensures your water is enjoyable and protects your health and home appliances.

Lower Your Home’s TDS with a Reverse Osmosis System

Low TDS water levels are recommended for better water quality, and that can be done with a reverse osmosis  system.

A reverse osmosis system can work as a simple and effective way of lowering your TDS levels. It’s also more eco-friendly than bottled water options that, even when the water starts off healthy, could end up exposing you to plastic contaminants.

Depending on your needs, each of these three options could serve as a smart solution.

A Countertop Water Distiller

If you primarily need purified drinking water, consider a countertop water distiller, which, as the name suggests, removes TDS via distillation.

Here’s how that works:

1. Boiling pure water away from TDS – A heating element boils the water until it evaporates. Most dissolved solids are left behind in the boiling chamber.
2. Condensing the evaporate into clean water – The evaporated H20 then travels to the carafe where it condenses back into water.
3. The water—boiled until vapor and then condensed into clean, safe liquid—is now ready for drinking.

While a countertop water distiller can prove immensely effective for drinking water, it can’t address other water uses throughout the house, like bathing or water-dependent appliances.

Filtration System

With a household water filtration system, your water passes through a filter. This filter sifts out contaminants from your water supply and keeps them inside the filter where they can’t re-enter your water supply. By the time your water reaches you (or your appliances), it has fewer harmful contaminants.

Generally speaking, a filtration system will remove contaminants, but not necessarily minerals. This trait could make filtration systems an ideal option for people who want the taste or health benefits of mineral water and find themselves less concerned about its other side effects like less efficient appliances and dry skin.

Reverse Osmosis System

A reverse osmosis system (often called an RO system) differs from a filtration system in a few key ways. 

An RO system uses reverse pressure to force water through a semipermeable membrane. Contaminants that can’t pass through this membrane are thus separated from the purified water and carried away via a secondary “reject” stream. Additional filters on either side of the membrane act as a way of supplying additional protection against TDS.

Because an RO system typically lowers mineral and chemical TDS levels, it can prove an ideal option for people wishing to avoid various side effects of mineral water.

An RO system achieves more efficient appliances, improves water taste, and supports healthier skin and hair. It helps purify water incredibly effectively such as reverse osmosis lead filtering. In fact, many water purification plants and waste treatment centers use this process. RO systems designed for residential use can differ in size and other important details.

For example, each of the available reverse osmosis systems:

• Filter out TDS like dissolved salt, harmful contaminants, and dirty sediment
• Improve the taste and smell of water
• Produces water of a higher quality than typical bottled water
• Are easy to install and maintain
• Can filter chemical contaminants like sodium, chloride, and lead
• Can filter bacteria like Salmonella and E. Coli
• Can filter viruses like Hepatitis, Enteric, and Norovirus Protozoa like Cryptosporidium and Giardia

Additionally, Rayne Water offers RO systems small enough to fit under your sink. When shopping for an RO system, comparing details like these across brands and models will help you prioritize the factors that matter most to you.

Is Your Water’s TDS Level Ideal?

Managing TDS levels in your water ensures better taste, appliance longevity, and health benefits. Regular testing and treatments like reverse osmosis or distillation can reduce excess minerals. By maintaining filtration systems, you can enjoy clean, safe, and great-tasting water, protecting both your home and well-being.

Rayne has delivered top-notch water softener & drinking systems since 1928. Our water solutions will save you money from day one. Get started with us today!

Sources:

1. Water and Waste Digest. What is Total Dissolved Solids (TDS)?. https://www.wwdmag.com/what-articles/what-total-dissolved-solids-tds 
2. PLOS One. Research on drinking water purification technologies for household use by reducing total dissolved solids (TDS). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8478203/#:~:text=The%20concentration%20of%20total%20dissolved,sodium%20%5B1%E2%80%933%5D. 
3. The Beet. Which Water is Best for You? Mineral, Alkaline, or Filtered. https://thebeet.com/which-water-is-best-for-you/ 
4. Rayne Water. Difference Between a Water Conditioner vs Water Softener. https://www.raynewater.com/blog/difference-between-a-water-conditioner-vs-water-softener/ 
5. NSF. Learn How Reverse Osmosis Works Straight From the Experts. https://www.nsf.org/blog/consumer/reverse-osmosis
6. WHO → https://www.who.int/docs/default-source/wash-documents/wash-chemicals/total-dissolved-solids-background-document.pdf
7. USGS → https://www.usgs.gov/data/compilation-total-dissolved-solids-concentrations-and-specific-conductance-measurements-upper

FAQs

What is water TDS?

TDS, or Total Dissolved Solids, is the combined concentration of all inorganic and organic substances dissolved in water, measured in milligrams per liter. 

It includes minerals such as calcium and magnesium, salts, metals, and trace organic compounds. TDS measures the total quantity of dissolved material, not which substances are present, so the figure alone does not indicate whether water is safe to drink.

What is a good TDS level for drinking water?

Under 300 mg/L is considered excellent and 300 to 600 mg/L is good, according to World Health Organization palatability guidance. Water becomes noticeably unpleasant above 900 mg/L and is widely considered undrinkable above 1,200 mg/L. 

The US EPA sets a secondary standard of 500 mg/L, though this is an aesthetic guideline covering taste and staining rather than an enforceable health limit.

Is high TDS water harmful to health?

Not usually. The World Health Organization has not set a health-based guideline value for TDS, and the EPA classifies its 500 mg/L threshold as a secondary standard for taste and appearance rather than safety. High TDS most often causes scale on fixtures, spotted glassware, and a metallic or salty taste. 

It can, however, signal the presence of specific contaminants, which only a full water test can identify.

What causes high TDS in water?

Most TDS comes from natural sources as water moves through soil and rock, dissolving calcium, magnesium, and other minerals along the way. 

Agricultural runoff adds fertilizers and pesticides, industrial discharge contributes metals and salts, and road salt raises levels in colder regions. Municipal treatment adds small amounts through disinfectants and pH adjusters. 

In the Southwest, Colorado River water reaches roughly 700 mg/L by the California border.

How do you lower TDS in water?

Reverse osmosis is the most effective method, forcing water through a semipermeable membrane that blocks dissolved solids and typically removes 90-99% of TDS. 

Distillation also works, boiling water and condensing the vapor while dissolved solids stay behind. Standard carbon filters and water softeners do not reduce overall TDS. Softeners exchange calcium and magnesium for sodium, reducing hardness but leaving the total roughly unchanged.