We’ve gathered all the information we could find to help you have a better understanding of TDS in drinking water.
What does TDS stand for? Total Dissolved Solids.
What are total dissolved solids (TDS)? Any minerals, salts, metals, cations (calcium, magnesium, potassium, and sodium), or anions (bicarbonates, chlorides, and sulfates) that are dissolved in water. These contaminants are present in water after passing through water pipes and the filtration process.
How do you know if you have elevated levels of TDS in your water?
When you have a high amount of dissolved solids in your water, you may notice deposits, colored water, staining, and/or a salty taste. These are not harmful, but rather noticeable aesthetic (such as smell, taste, or color) effects when TDS is above 500 parts per million (ppm).
When you invest in a fridge, pitcher, or faucet filter, you expect pure water, right? Unfortunately, most filters are not designed to reduce TDS. The most popular way to reduce total dissolved solids in your water is to invest in a Reverse Osmosis Water Filter System.
How To Measure TDS
One of the easiest ways to test TDS in your water is by using a TDS meter. A TDS meter is a small hand-held device that estimates the TDS level by measuring the electrical conductivity of the particles in the water.
A TDS meter will NOT measure the overall water quality. Healthy minerals in water like potassium, magnesium, and calcium can cause your reading to spike. TDS meters do not directly measure heavy metals like lead or other contaminants like pesticides, pharmaceuticals, or hexavalent chromium.
Are you wondering if you should invest in a TDS meter? While the decision is ultimately up to you, it is not necessary to have a TDS meter.
HM Digital Water Quality Tester
If you want to know what is in your water, we recommend testing your water with a Water Test Kit. Water Test Kits will tell you exactly what is in your water— including dissolved solids.
Watersafe Well Water Test Kit
Are you concerned about TDS in your water? Here are a few water treatments you can try:
Reverse Osmosis
Reverse Osmosis is the most popular way to remove TDS from your water. Reverse osmosis forces water under pressure, through a synthetic membrane. The membrane will only allow molecules smaller than 0.0001 microns to pass through it. Molecules of dissolved metals and salts are large compared to the water molecules, so the water that passes through the membrane leaves the metals and inorganic salts particles behind.
PuROTwist 4000 Reverse Osmosis System
Distillation
Distilling water involves boiling water to produce water vapor. The water vapor then rises to a cool surface and then condensed back into the liquid form. Dissolved salts are unable to vaporize and remain in the boiling solution.
Dental Purity Stainless Steel Water Distiller
Deionization
This process involves water passing through a positive and negative electrode. Ion-selective membranes cause the positive ions to separate from the water and move towards the negative electrode. The result? De-ionized water with high purity. However, before this can happen, the water must first be passed through a reverse osmosis unit to remove the non-ionic organic contaminants.
Common questions about TDS in water:
Q: After I installed my filter, the TDS was high, why did this happen?
A: Carbon filters can raise TDS. This is usually more prominent right after you install it. Once you flush your filter, TDS will drop back down. This momentary increase is not harmful.
Q: I used a TDS meter and the read was positive. Is there something wrong with my water filter?
A: Nope! There’s nothing wrong with your filter. A TDS meter is a broad test used to determine levels of TDS in liquid. Most meters measure inorganic and organic substances in molecular, ionized, or micro-granular suspended form. Common TDS substances include calcium, phosphates, nitrates, sodium, potassium, and chloride. When water is void of TDS, it can be flat, have an unpleasant taste, and could be lacking in important and healthy minerals your body needs. If you think that there is something wrong with your filter, you will need to do a test that focuses on the contaminants that the filter is supposed to remove. A TDS meter tests too broad of range and will not give you an accurate reading on whether your water is functioning as it should.
Q: I used a TDS meter and the results were way higher after the water was filtered. Is this normal?
A: Depending on the type of filter media that is being used, the TDS reading can be much higher after the water is filtered. Sometimes carbon filter media can release carbon fines during initial use. These harmless particles can cause your TDS reading to be higher. Once the filter is properly flushed, TDS will decrease, but if you have a carbon filter, you will consistently see higher TDS readings. Using a TDS meter to test your filtered water is not a good measure of whether your filter is working or not.
Why is it important to measure and remove TDS?
TDS do not present a risk to human health, the Environmental Protection Agency has not set a mandatory TDS limit, but suggests a maximum level of 500ppm. At or above this level, consumers may notice deposits, colored water, staining, and/or a salty taste. These are not harmful, but rather noticeable aesthetic (such as smell, taste, or color) effects when the TDS is above 500ppm.
Water Hardness
If you have hard water, you may have high levels of TDS in your water. If you notice that you have dry hair, spots on kitchen utensils after they are washed, or regularly occurring toilet stains, these are indicators that you have hard water in your home. Hard water is more specific to dissolved calcium and magnesium in the water. This is measured differently than TDS.
Pools and Spas
High levels of TDS in water can become a huge problem for pool and spa owners. TDS can be the cause of constant maintenance.
The point is, the purer your water is, the healthier you and your family will be. Find exactly what you need to create a healthier environment in your home by shopping at FiltersFast.com.
Katie says
Danelle,
Thank you for reaching out to us. It is common to see a higher TDS after filter replacement. Typically, the carbon filters will release carbon fines at first. Once those rinse out the TDS should go back down.
One of the best ways to know when to replace the filters/membrane is to calculate the TDS rejection rate. 55 PPM TDS before filtration and 455 PPM TDS after filtration indicates the system is removing 87.9% of TDS. Most manufacturers recommend replacing the filters/membrane when that effectiveness drops to 75%.
Please feel free to reach out to us if you have any more questions.
Danelle S. says
So had all the filters changed including membrane. The water is 055 with TDS meter. Is this good? At what point in the TDS reading should I change the filters with just 1 senior in the house?
Tap water is at 455 with the TDS reading in Southern Ca.
Thank you for your website. Danielle S.