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What is a TDS meter?

A TDS meter is a small hand-held device used to indicate the Total Dissolved Solids in a solution, usually water. Since dissolved ionized solids, such as salts and minerals, increase the conductivity of a solution, a TDS meter measures the conductivity of the solution and estimates the TDS from that reading.

TDS meters may be referred to as TDS testers or PPM (parts per million) testers, but all of these are different names for the same thing. TDS meters can be purchased for as low as $10, but more advanced models can cost $1,000+ based on the level of accuracy and additional features offered.

For example, a basic TDS meter may only measure the amount of total dissolved solids in a solution while an advanced model may be able to check salinity, temperature, and more.

Why should you measure TDS?

A high TDS level means you have an abundance of dissolved solids in your water, which typically includes minerals. Over time, the constant presence of these minerals in your water can lead to scale buildup in your pipes and appliances which shortens their lifespan and effectiveness. By knowing your TDS level, you can determine whether you need something to combat this issue, like a Salt-Free Water Conditioner or a water softener for, especially hard water.

Salt-Free Water Conditioners inhibit scale buildup by transforming dissolved hard minerals into harmless, microscopic crystals that don’t accumulate over time. Salt-Free Water Conditioners can protect pipes and plumbing, decrease spots and stains on dishes and shower doors, increase the life of brighter clothing, and more, without wasting salt or water. Keep in mind that a Salt-Free Water Conditioner is different from a water filter. The ultimate goal of a water filter is not to remove all solids in the water.

What does TDS not measure?

A TDS meter does not measure contaminants. It will not tell you if your water is healthy. The TDS meter reading simply refers to the amount of total dissolved solids in your water, it will not tell you what those solids actually are and if they are harmful for your health.

For example, you could have a high TDS meter reading but no harmful contaminants in your water. Some healthy minerals like potassium, magnesium, and calcium can actually cause your TDS meter to spike. So, any water filter with a remineralizer could cause a high reading on your TDS meter, even though the remineralizer is adding good minerals that you want.

On the other hand, you could have a low TDS level even if several harmful contaminants are present in your drinking water. Your water could have heavy metals like lead, or other contaminants like pesticides, pharmaceuticals, or hexavalent chromium. The TDS meter will not pick these contaminants up.

This is why you shouldn’t rely on a TDS meter to determine your water quality. You need to understand not just how many dissolved solids are in your water, but what those solids are and if they’re harmful for your health.

Does a high TDS meter reading mean you need a water filter?

To summarize, your TDS meter reading is simply a quantitative measure of the amount of dissolved solids in your water, it is not a qualitative measure indicating what those substances are and whether they are harmful. Your TDS level can be used to determine if you need a Salt-Free Water Conditioner to prevent scale buildup from mineral accumulation in pipes and appliances, but you should not rely on your water’s TDS alone to decide whether you need a water filter.

To decide whether you need a water filter for your home, your best option is to request a detailed water quality report from your local water supplier. If there are contaminants in your water, knowing which ones are present will help you choose a water filter for your home.

When choosing a water filter, the goal should not be to remove all TDS because some of these are healthy minerals that contribute to a good taste for your drinking water. All Aquasana water filters utilize Claryum® selective filtration technology to remove harmful contaminants while retaining healthy minerals such as calcium, magnesium, and potassium.

To remove the most contaminants, you’ll want to look at reverse osmosis water filters. However, some of these RO filters actually remove too many minerals, so make sure to purchase one with remineralization technology like our OptimH2O® Reverse Osmosis + Claryum® water filter. There are many under sink or countertop water filter options, offerings various levels of filtration power depending on what contaminants you need to address. While each of the options above offer filtered water in a specific area where they’re installed, if you want filtered water throughout your entire home we recommend a whole house water filtration system.

For additional information about TDS and water filters, contact us and we’ll answer your questions.