Lishtot - Water Technology - The first personal water test


Video answers to the most popular questions

Frequently Asked Questions


TestDrop is the most convenient and inexpensive way to regularly test your water for contaminants. Most people have no idea about the quality of the water they drink, and for such an important and life-sustaining resource, people should know more. Whether you're hiking outdoors, traveling to another country, interested to know what's coming out of your home tap or just looking to know how your bottled water compares to your tap water, TestDrop is here to provide answers.

TestDrop allows you to test any type of water. By simply pouring a water sample into a plastic cup, and taking a reading with the TestDrop next to the cup, you can know by the blue or red lights if certain contaminants have been identified in the water. You can also send the recent tests you've done to the app, take a video, add your tests to the Lishtot Global Water Map, and/or learn more details about the level and type of contaminants in your drinking water. There is no contact between the TestDrop and the water, and there is no requirement for adding chemicals or waiting for some reaction. The whole process is complete in 5 seconds.

The TestDrop should be used anywhere and everywhere possible for testing your drinking water. Part of our goal at Lishtot is to help the world know more about its water, and to achieve that we are building a Global Water Map which gets better with more user-generated information. You can test tap water, bottled water, and natural water like streams and rivers. You can test filtered water and distilled water. At home, at work, and in the wilderness. In public water fountains and restaurants. Any type of water that you want to drink, you can test.

Please email us at for information on large purchases.

You can use the device for thousands of tests and will get the blue or red LED response. Greater detail such as graph appearance and likelihood of contamination will require use of a Bluetooth-supported app available for smartphones.

Product & Technologies

Based on well-known chemistry principals, the patented technology behind the TestDrop and future products to be sold by Lishtot detect electric fields associated with the presence of water. If contaminants are present, those electric fields are distorted in various ways, depending on the type of contaminant present in the water. The sensor records a result on the device, and then via a Bluetooth connection can send the information to the Lishtot mobile app for further details.

The TestDrop does not need to be connected to the internet, partly because we want people to be able to use this device anywhere, including at the supermarket and in the wild. The device can perform an unlimited number of tests without having to send data to our mobile app. The last ten tests you run will be transferred to the app once you send data from your device to your phone.

The core technology behind Lishtot's products detects electric fields that are related to water. These fields are generated and altered by interactions with contaminants, and in order to view those interactions, a vessel is needed in order to watch the interplay between water, contaminants, and the vessel itself. Flowing water simply does not produce this detectable electric field. Furthermore, it is also much simpler to get an accurate and reliable result with a sample of water in a still vessel.

This happens when the device is establishing a Bluetooth connection with the smartphone application. Please make sure your location and Bluetooth functionalities are turned on. This should take about 10 seconds before you can begin regular testing. If the blinking persists it could mean that your smartphone is having trouble connecting with the TestDrop. Please contact our customer support team at so we can help you find a solution.

The issue probably has to do with a bad battery in the device. Please send an email to and we will get that sorted out for you immediately.

There are numerous reasons why this could be happening. It could be the water you are testing is in fact contaminated, or that the baseline standard in your location is below the baseline criteria that Lishtot has established for clean water. It can also be a result of not following the testing guidelines that Lishtot provides for using the TestDrop properly. Finally, it could be that the device is malfunctioning. Before reaching out to us, try to purchase several different brands of mineral water at the nearest store and pour into clean plastic cups and test them. If the TestDrop continues to indicate red, please contact for more assistance.

Please ensure that your Bluetooth and location settings are turned on. The device should feature blinking red and blue lights to show that it is working to connect to your phone. If you are still unable to connect the device to your phone please email us at

When you swirl or tilt the water in the cup, you charge the cup. The detector can detect the electric fields associated with the cup. Protein, heavy metals, bacteria, organic pesticides and other materials interfere with the charging of the cup, leading to different fields. The sensor can determine the quality of the water by the electric fields it measures around the cup.

Try to find some clean water, possibly from an unopened plastic bottle of mineral water. Run a test as shown on the website. You should get a blue light. You can add a very small amount of soap or spit in the cup, swirl again, and test. You should get a red light that never goes back to blue after repeated testing. If so, your device is working properly.

We expect so. Please make sure that your app is up to date and that any new software for your TestDrop has been uploaded to the device.


The TestDrop gets the best results when done using plastic cups or water bottles. Any other material interferes with thesignal. The technology currently does not work with glass, ceramic, wood, or metal vessels. TestDrop is extremely sensitive to even the slightest contamination. For reusable bottles and glasses, even something that has been washed with soap and rinsed thoroughly, many times the TestDrop will detect that soap or other residual materials.

The TestDrop sensors are designed to work specifically with hydrophobic containers - containers that repel water. Our reason for designing this way is that, in the case of contamination, the contaminants will actually stick to the walls of the container, enabling Lishtot to detect even the most miniscule levels of contamination. Polypropylene (PP) and polystyrene (PS) are the best materials for testing. Look at the bottom of a cup and it should say PP or PS or have their corresponding recycling numbers, 5 or 6, respectively. PET cups (#1 printed on cups) may also be employed.

It is important to swirl the water in the container or tilt the cup in order toallow the water you are testing to interact with the exposed sides of the plastic cup. We suggest filling a cup to just over one-half full and swirling gently for about ten seconds, tilting on one side just until the water reaches the top of that side. Let the water settle. Measure in the "L" motion as shown in the How-To Videos.

We discourage reusing cups, especially if you have seen a red light. Contaminants may remain on the cup and interfere with future measurements.

In developing our technology, we found that different surfaces-wood, glass, plastic, metal, formica-have different effects on electric fields associated with the plastic cup. Holding the cup in one hand removes this problematic source of this signal "noise".

Bottled water can be placed on a table in order to conduct testing as per the demonstration video.

You should wait around 3 seconds between tests.

Try to get the water back into the water stack and have the sides dry if possible.

We have found that one does not have to touch the cup when doing a proper measurement. If you do touch the cup, the results should not be affected.

Polypropylene (PP) and Polystyrene (PS) are preferred plastics. Look for the PP 05 or PS 06 on the bottom of the cups you use for testing.

Generally no. There are some soft drinks that do work with the device, but in general the presence of numerous chemicals in soft drinks makes testing not possible.

We encourage users to test water at least once a day. You may test more frequently, as water providers often change their source of water several times in any given day.

Yes. Please see the videos on our website for how to check mineral water bottles prior to opening.

Extremely cold water that yields condensation on the outside of a cup or extremely hot water that produces steam and/or condensation on the inside of a cup will give a red light, even if the water is clean. Water should be between 20 and 50 degrees Celsius.

For best results, water from tap or bottle should be poured directly into a clean disposable cup for testing. One should avoid placing the water into a jug, glass or other container as such containers may impart impurities into the water prior to testing.


During the glass bottle manufacturing process, an organic material is coated on the glass. The TestDrop may detect this material and give a red light. Although this material is approved by the FDA, TestDrop may still detect it.

There are dozens, possibly hundreds, of regulated and unregulated chemical contaminants in water. We have done our best at Lishtot to design a product that can be used with any water source and as wide of a variety of plastic cups as possible. It is possible that the TestDrop can yield a false result. No diagnostic device is 100% accurate. Lishtot compares test data to all other data we have processed up until that point. It may be that the water includes contaminants which we have not evaluated and are thus not included in our algorithms. In order to make TestDrop useful for you, we have developed the technology to work with commercially-available plastic cups and with water from sources from around the world. There is a possibility that not all cup-water combinations will yield results that match those recognized by Lishtot's algorithms. We analyze data that come to us to better improve the algorithms on the testing device.

You can see a link to the list of contaminants that the TestDrop can detect here.

Also, because this is an interactive product that is accessible to everyone, it is important to note that you, as a user, are part of the testing process, and while we feel like we've done our best in explaining how to use the product, mistakes can always be made. If a test was not conducted specifically according to our guidelines it is possible to get a wrong answer.

There are several reasons this could have occurred. It is possible that you sent similar, but not exactly the same, water. As an example, water can vary widely even just based on the exact location of where it stopped in the pipe. "First draw" water that has sat in a pipe for over six hours is notoriously dirtier than water that flows more frequently.

It could also be that the contaminated particles stuck to the wall of the test cup, and the water that was brought to the lab is water without those contaminants which were at low concentration initially.

Or it is possible that material detected by TestDrop is not on the list of materials tested by your laboratory. There are hundreds of possible water contaminants and not all labs look for every one.

Knowledge is power. It's true that for many in the world, particularly in impoverished developing countries where there is only one source of drinking water, knowing that that source is contaminated may or may not help immediately (although we argue it will in the long term). However, in the developed world where there are numerous options for drinking water, and the government, municipalities, and corporations are responsible for the quality of the water that they deliver, this device is extremely valuable. Imagine a scenario where Lishtot customers detect lead or E. coli contamination in a region or city section long before it would have ever been made aware to the local authorities. Or perhaps a large beverage company has bottled a bad batch of water or the local grocery store left those bottles too long in the sun. You will know first, and together with your fellow Lishtoters, you will hold the proper authorities accountable and get them to correct the problem as soon as possible. In the meantime, you can check for alternative water options.

You should care about bacteria and organic material that is in your water. There could be things like pathogenic bacteria or water-based parasites which could cause almost immediate illness if ingested. The symptoms could be mild or severe. Biological contaminants, and not heavy metals or chemicals, cause most water-associated illnesses and death in developing countries. Heavy metals at parts-per-billion concentration generally cause health injury over years of ingestion. For heavy metals like lead and cadmium, these materials can be dangerous over short or long periods of time, particularly if the water is consumed for years. Although you may not see the effects right away, they can cause serious harm to you and your loved ones and will almost certainly inhibit your quality of life in some fashion.

Knowing whether there is immediate or long term danger inherent in your water should be a chief concern for all who consume water. Boiling water may kill bacteria but it will do nothing to remove heavy metals.

The TestDrop tests for biological molecules associated with bacteria, heavy metals including lead, mercury, and cadmium, some organic pesticides, toxins including ricin, and organic waste like kerosene and oil.
Click the link for a list of contaminants the TestDrop can detect.

Click here for the continually updated list.

Lishtot developed the TestDrop in order to help customers all over the globe know more about their water. We felt the best way to do this was to hold an extremely high standard for what we consider to be quality water i.e. water that we ourselves would want to drink. We consider all other water to be adulterated-but not necessarily dangerous-water.

It is important to note that water that does not meet our criteria, although registering with a red light on the TestDrop, is not necessarily undrinkable. In fact, many locations have different standards for water, and many will not meet Lishtot's standards particularly given the sensitivity of the TestDrop and its underlying technology.

We have decided to issue warnings of caution instead of telling our customers to flat out not drink the water. If the test indicates blue, we are letting you know that the detector did not detect the contaminants on the website list at the concentrations stated there.

In the end, the more data we have the better we can serve our customers and the planet in painting a picture of water quality around the world. As our algorithms improve with millions of customers testing and using our devices, we will know where standards need to be adjusted based on geography and techniques used in nearby treatment plants.

In future releases of our products, we will add the option to adjust to our suggested contamination level sensitivity based upon your location.

The more information we have, the better we can help serve Lishtot customers. Our algorithms improve every time a test is done. Eventually we will be able to set specific standards and criteria for the street, the building, or even your house. This will produce a specific water profile that you should expect for the water you are drinking, and if there's any change in that profile, however miniscule, we will be able to alert you and possibly alert your water utility to get them to monitor and fix any problems as necessary. Your standards and quality can be compared to others in different regions and geographies, and even to bottled water in your grocery store or in the stream behind your house. More data lead to better knowledge and with better knowledge comes better tools to help improve all of our water.

Our application relies on geography in order to tell us what type of water quality you should expect in your region. Knowing the location of any test you do helps us improve our algorithms to fully understand how water quality changes in different places. Also tap water data can be uploaded to our Global Water Map if we know the location of the water that was tested.

There are a few reasons for different results. It is possible that you were testing a water source that changed quality during the time between the tests. For example, natural water changes constantly, and tap water can change based on when and how long it was standing in a pipe. It is also possible that your test method was altered or you differed from the guidelines that Lishtot recommends for testing. It is also a possibility that our algorithm has been updated to include or exclude those recent contamination levels from the threshold criteria that we use to set our baseline standards for clean water. Also, low amounts of contaminants such as chlorine used to disinfect water can lead to blue and red tests if run multiple times.

Unlike tap water which is generally treated with "chlorine" (hypochlorite), mineral water is treated with ozone to kill bacteria. Ozone is unstable and breaks down quickly. As you pour mineral water out of the bottle, air from the room sits over the remaining water. Bacteria or other contaminants from the air might land in the water, and over the space of a few days bacteria may grow and/or organic contaminants might dissolve in higher and higher concentrations. The red light may well be real. Our testing generally has mineral water giving a red light when tested in plastic cups after a few days of being open.

Bottled water is a broad category of water that can be anything including filtered tap water, or water that has been filtered so purely that companies add the minerals they want back into the water, or water that has been derived directly from a fresh spring and is cleaned and bottled.

Assuming that the test was performed properly, it is possible that any one of these processes was ineffective enough to allow some contaminants to remain. It is also possible that this bottled water was exposed to sunlight in the plastic bottle and the plastic released some chemicals into the water. If the water is in a glass bottle, it is possible that an organic coating material was used during the glass manufacturing process and the TestDrop is detecting that coating. And finally, perhaps someone has already had a sip of your water, or the test was conducted differently than the testing guidelines that Lishtot requires. In our labs, we find that bottled water opened and allowed to stand for a few days (with room air over the water, inside the bottle) often shows degraded profiles compared to those of samples taken from just-opened bottles.

The TestDrop and the sensor technology within can identify proteins from your saliva that were deposited into the water when you drink.The water is obviously not dangerous for your continued consumption. But think about it: would somebody else want to drink from your cup?

No. The red light means that the detector has identified something in the water that should not be there. For example, if you have clean water, it should give a blue light. If you drink a bit from the plastic cup and measure again, the red light may come on. The protein from your saliva has changed the water behavior and the resulting measurement. But your saliva is not dangerous, though others might not want to drink water with someone else's saliva! A red light suggests that the water in the plastic cup is somehow adulterated; a blue light means that the materials listed on our website as contaminants were not detected at their test concentrations.

There can be a couple of reasons. Tap water includes chlorine for disinfecting the water. Over time, chlorine can eat away at the plastic cup and cause a change from blue to red. Alternatively, a contaminant at low concentration may slowly build up on the plastic and cause a different outcome, presenting as red in place of blue. Additionally, pollution from then air might contribute to changed readings if the water sat for an extended period of time.

There are cases where the detector can identify lead or other contaminants below their legal thresholds. For example, under some conditions, the sensor can identify 5 ppb of lead which is legal in the US and elsewhere.

At Lishtot, we do our best to identify as many water contaminants as possible at real-world concentrations. There are hundreds of regulated and unregulated water contaminantsknown to the authorities. We cannot and do not claim that we can identify all of them. A blue light means that the contaminants listed on the Lishtot website do not appear to be present at the concentrations listed there in your water sample. We never suggest that any user drink a given water sample.

Please go to the app and make sure that each device has the newest software installed and similar cutoff values.

That is not a question we can answer. Our device can be used to test water from any relevant source.

Go the app and follow the instructions there on how to update tap water for the location where you are testing.

Lishtot is working with local laboratories for water testing. If your water is often red even after letting "first draw" water run out of the tap, you may want a one-time water analysis to see if there are any problematic materials like lead or organic compounds present in your water.

Yes, through the app, the cutoffs for red/blue light function can be changed to reflect local water conditions.