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Just Plumbing | Understanding TDS in Reverse Osmosis Water: What You Need to Know

Understanding TDS in Reverse Osmosis Water: What You Need to Know

There are three important qualities science has attributed to clean water. These are characteristics that anyone with a rudimentary knowledge of elementary science is well aware of. Clean water must be tasteless, colorless, and odorless. Simple, right? Well, not always. One thing you have to know about water is that it’s an excellent solvent. So, it can dissolve certain substances that may alter the ideal status quo. This means the water may have an altered appearance, smell, or taste.

Some of these solvents are categorized as TDS, which means total dissolved solids in full. Unfortunately, TDS has been demonized by many as being very harmful in drinking water. That’s not true. There’s a nuance to it. Whether TDS is harmful or not depends on the nature of the dissolved solids in the water. As you continue reading, we hope that you will unlearn what you know about CDs and learn what it is.

What’s TDS?

TDS, as we mentioned earlier, means total dissolved solids. It describes the total amount of organic and inorganic elements in a body of water. This means that anything else aside from the water itself is classified as TDS. The more materials are dissolved in your water, the higher the TDS level will be.

TDS is capable of altering the color, smell, and taste of your drinking water. It’s also capable of causing buildups in your water-using appliances and pipes in the home. TDS includes elements such as cations, anions, salts, metals, and minerals. We’ll give some examples for each of them. They are more popular than you think.

TDS includes the following:

  • Bicarbonates
  • Minerals (calcium, fluoride, magnesium, and potassium)
  • Metals (Aluminum, cadmium, copper, iron, zinc, and lead)
  • Microbes (parasites, viruses, and bacteria)
  • Salts (sodium, chloride)
  • Chemicals (chlorine, arsenic, sulfates, chloramine, herbicides, and pesticides)

To truly understand the nature of total dissolved solids, you ought to know where they originated from. A one-size-all answer will be ‘anywhere.’ As water travels from its source to your pipes, it will pick up various substances or elements in transit. It could be from mineral springs, salt deposits, carbonate deposits, rivers or lakes, and so many more.

Some of these dissolved solids are beneficial to the human body if present in the right amounts. We’re talking about calcium, magnesium, and sodium. On the flip side, some of these chemicals may be harmful to the body. Good examples include lead, copper, iron, and zinc.

Though a significant amount of TDS comes from the natural ecosystem around us, we also play an equally significant role in bringing TDS-rich water to our doorsteps. Chlorine, for instance, comes from water treatment plants. Old plumbing systems are known to add lead to water that passes through. Then, we have herbicides and pesticides from agricultural run-offs.

What’s the Ideal TDS Level For Drinking Water?

A lot of people think the total absence of TDS in your water makes it perfect for drinking. That’s a misconception. Having TDS in your water doesn’t make it bad for consumption. As long as it’s not beyond a certain level, you can drink water containing TDS. So, what’s the ideal level? According to the Environmental Protection Agency, the maximum TDS level for drinking water is 500 ppm. If the TDS level is above that, the water can still be consumed as long as the harmful solids are not present. However, if the water TDS level is above 1000 ppm, it’s unfit for human consumption.

Measuring TDS in water

The easiest way to test the level of TDS in your drinking water is via a TDS meter.

Total dissolved solids increase the conductivity of water. The TDS meter determines the level of TDS in your water by measuring its conductivity. The higher it is, the higher the TDS level, and vice versa. Most TDS testers measure in ppm, which means parts per million. In layman’s terms, this means there’s 1 mg of dissolved solids for each 1 kg of water.

Despite its ease of use, it’s not the best way to check the TDS level in your water because it doesn’t reveal the nature of the contaminants in your water. Also, it can only detect dissolved solids that produce ions in the water. This means if the contaminant is something like pesticide, motor oil, etc., they will remain undetected by the TDS meter.

What Happens When You Consume Water Rich in TDS

A lot of things happen when you drink or use water that has an abundance of dissolved solids. Let’s talk about some of them:

It Will Affect the Taste of Your Food

We earlier mentioned that when the water has a high TDS level, its taste, color, and odor can be altered. So when you drink it, you’ll notice that it doesn’t taste the way it should. What we didn’t tell you is that the same thing applies to the meals you cook. If you use TDS-rich water to cook food, it will have an unpleasant taste because of the content of the water it’s absorbing. In this case, getting a reverse osmosis water system to filter your drinking and cooking water will be ideal.

Just Plumbing | Understanding TDS in Reverse Osmosis Water: What You Need to Know

It Causes Dryness and an Itchy Feeling in the Hair and Skin

If you have dry and itchy skin or hair, there’s a very high chance that you’re bathing with water that has a high TDS level. If there is a strong presence of calcium and magnesium in the bathing water (two water-hardness minerals), it will alter the oil production chemistry of your skin. This will affect the ability of your skin to moisturize itself and leave you with persistently dry skin.

Also, the residue left on your skin can make it prone to skin conditions such as acne, rashes, inflammation, itching, pimples, and so many more.

As for your hair, it will be hard to clean it properly with hard water. This will cause a buildup over time, causing your hair to lose its natural luster. No amount of hair or skin products will reverse this unless you change the water you bathe with.

Tooth Discoloration

The mineral responsible for this is fluoride (in excessive amounts). Ironically, fluoride is good for the teeth in the right amounts. However, when you drink water that’s rich in fluoride, it will gradually change the appearance of your teeth.

Scale Buildup in Pipes, Plumbing Fixtures, and Appliances

TDS-rich water can be a menace to the home. Firstly, it causes a buildup of limescale in your pipes and your plumbing fixtures. Secondly, it could shorten the lifespan and effectiveness of water-using appliances such as water heaters, dishwashers, and laundry machines.

Thirdly, your dishes and glasses will have water spots on them. Lastly, surfaces that come in contact with water frequently, like your countertops, faucets, sinks, shower doors, and tubs, will have soap scums, scale deposits, and stains.

How to Reduce or Get Rid of TDS in Water?

Eliminating TDS in your water may be extreme, especially if you have some beneficial minerals inside. What will be more prudent is reducing the TDS in your water to an acceptable level. So these are the best ways to reduce TDS in water:

Reverse Osmosis Home System

If your water TDS level is above 500 ppm, the reverse osmosis water system is best equipped to treat it. This popular water treatment system has several filters, including a semi-permeable membrane that keeps a lot of contaminants at bay. This system can reduce the TDS level to less than 50 ppm. However, we don’t recommend a reverse osmosis home system if the TDS level in your water is more than 2000 ppm.

Water Deionizer or Distiller

If you insist on going extreme and eliminating dissolved solids in your water, using a water deionization system is your best bet. This is the only water filtration process that gives you “pure” water. This is ideal for any level of TDS, regardless of how high it may be.

Is Low TDS in Water Bad For You?

The short answer is no. Water is considered to have low TDS when it measures less than 100 ppm. What it means for water to have low TDS is that there are very little amounts of dissolved solids in it. It doesn’t make your water bad; it will just lack healthy minerals like calcium and magnesium. A good TDS level for water with such minerals is 250 ppm.

On the flip side, low TDS is a good thing if the dissolved solids are pesticides, lead, and other harmful contaminants. In fact, 100 ppm is a dangerously high TDS level if the dissolved solids are any of the above-mentioned elements.

Myths Regarding TDS in Water

There have been a lot of misconceptions about TDS. You deserve to know better, and that’s why we want to address some of these myths.

  • TDS is an indication of water quality. This is one of the most popular myths about TDS. The fact is on its own, TDS cannot quantify the quality of water. It’s simply a measure of the amount of dissolved solids in your water. A true water quality test will take other indicators into account, such as microorganisms, disinfectants, disinfection byproducts, inorganic and organic chemicals, etc.
  • If my TDS level is not very low, the water filter isn’t working. Again, a myth. One thing to know about TDS filtration is that not every water treatment system can do the job. So, it doesn’t mean your water filter is not working; it simply means you’re using the wrong water filter. Only two systems can do the job – a deionizer and a reverse osmosis water system.
  • TDS is bad. Not exactly. It depends on the nature of the dissolved solids. An optimal range of healthy minerals in your water makes it good, even high quality. It’s when you have harmful elements that TDS in your water is a bad thing.


People pay too much attention to the TDS level in their water. In the process, they ignore what they should be looking at – what type of dissolved solids are in your water. A high TDS level may be dangerous or not, depending on what your water contains. To recap, the signs that your water has TDS include an unpleasant taste or smell, itchy and dry skin or hair, discolored dentition, and scale buildup in the home. The first course of action when you notice any of these is to check the content of your water. If you notice harmful contaminants, we recommend using a water deionizer for total elimination. On the other hand, if you have more healthy minerals, use a reverse osmosis water system to reduce TDS to an acceptable level. That’s the right way to deal with TDS content in your water.