Digital TDS Meter, TDS-3 beige pen-style meter with LCD display and three pink buttons, front view
Digital TDS Meter
Does this instrument measure the parameter you need, in the units and range you require?
- Worth considering for
- Readers who need the specific measurements or indicators described in this instrument’s documentation.
From $24.75
Archived USD price · Check today’s price with Crystal Quest.
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A documentation-based review of the manufacturer’s listing and specifications. How we reviewed it
Our assessment
The Digital TDS Meter belongs on a comparison list when its documented application matches your needs. The important next step is to verify the configuration and compatibility, rather than deciding from the product photograph alone.
What the listing gives you
- Configuration choices are documented
Model: TDS-3 (TDS + Temp), TDS & EC (TDS, EC + Temp)
What deserves a closer look
- Fit comes first
Check the measurement range, calibration instructions and what the device cannot measure. A single reading is not a complete water analysis.
- Look beyond the listed price
Review calibration, consumables and handling instructions before comparing the instrument with a laboratory service or another meter.
- Compare the same configuration
The source lists 2 configurations. Use the model and part-number table below so that a size, package or optional component is not mistaken for a different specification.
These are our reading of the published information and our buying considerations. They are not measured performance results.
The specifications, in context.
Values below are published by Crystal Quest. Specifications may describe different configurations; read the model labels and compare the complete source tables in the reference section.
The listing does not provide a separate two-column specification table. Available technical details remain in the full manufacturer reference below; confirm any missing measurements directly with Crystal Quest.
Multi-column comparison tables are preserved in full under Manufacturer reference.
Choose the configuration carefully.
Check the measurement range, calibration instructions and what the device cannot measure. A single reading is not a complete water analysis.
Model & part-number reference 2 configurations
This is a reference table, not an ordering form. SKU and option names are reproduced from the manufacturer snapshot.
| Configuration | Part number / SKU | Listed price (USD) |
|---|---|---|
| TDS-3 (TDS + Temp) | Not specified in listing | $27.45 |
| TDS & EC (TDS, EC + Temp) | Not specified in listing | $24.75 |
Price snapshot from November 8, 2026. This is not a current offer or a stock confirmation.
Think beyond day one.
Review calibration, consumables and handling instructions before comparing the instrument with a laboratory service or another meter.
- Match the exact model or SKU before relying on an installation diagram or replacement schedule.
- Ask what the quoted package includes and what must be supplied separately.
- Keep the manufacturer’s operating instructions with your service and replacement records.
Frequently asked questions
Does this instrument measure the parameter you need, in the units and range you require?Our reading
The Digital TDS Meter belongs on a comparison list when its documented application matches your needs. The important next step is to verify the configuration and compatibility, rather than deciding from the product photograph alone.
Who is Digital TDS Meter worth considering for?Best fit
Readers who need the specific measurements or indicators described in this instrument’s documentation.
What are the configuration constraints and installation requirements?Fit & plumbing
Check the measurement range, calibration instructions and what the device cannot measure. A single reading is not a complete water analysis.
What are the ongoing maintenance and filter replacement considerations?Ownership costs
Review calibration, consumables and handling instructions before comparing the instrument with a laboratory service or another meter.
Go back to the source.
The full product information below is supplied by Crystal Quest, including its own descriptions and claims. We have reorganized the typography and tables for reading. This material is separate from Elorova’s assessment.
Product overviewManufacturer material
Is my reverse osmosis system still working? Is my filter doing anything? What is actually in my tap water? A TDS meter gives you a first answer in about ten seconds. Dip it in a glass and it shows total dissolved solids (TDS): the minerals, salts and metals dissolved in your water, in parts per million (ppm).
We use TDS meters constantly to check that an RO membrane is still doing its job. This is the same quick check, in your pocket.
At a glance
- Reads TDS in ppm in seconds, with no strips or reagents
- Shows water temperature on both models
- HOLD button freezes the reading so you can lift the meter out and read it
- Protective cap keeps the probes clean between tests
- Two models: the TDS-3, or the TDS & EC that adds electrical conductivity in µS/cm
Which model is right for you?
- TDS-3 (TDS + Temp): the simple one. Three buttons (HOLD, TEMP, ON/OFF) for TDS and water temperature. Right for checking tap, filtered and RO water at home.
- TDS & EC (TDS, EC + Temp): adds an EC reading in microsiemens per centimeter (µS/cm) and switches between readings with the SHIFT button. Reads TDS from 0 to 9,999 ppm and EC from 0 to 9,999 µS/cm, accurate to ±5%, with automatic temperature compensation, a titanium alloy electrode and auto shut-off after 5 minutes. A good pick for hydroponics and aquariums, where EC is the usual unit.
How to check your RO system
- Run cold water from your kitchen tap for a few seconds and read a cupful.
- Read a cupful from your RO faucet.
- Compare. Reverse osmosis removes most dissolved solids, so the RO reading should be far lower than the tap reading.
- Write the numbers down and repeat every month or two. When the RO reading starts to climb, it is time to look at your membrane and pre-filters.
What a TDS reading cannot tell you
A TDS meter measures how easily water carries a small electrical current, then converts that to an estimate in ppm. It counts everything dissolved together, healthy minerals like calcium and magnesium included, and it does not say what any of it is. A low number is not a safety verdict: a TDS meter cannot detect lead, PFAS, bacteria, nitrate or pesticides. For those, a certified water test is the answer. Learn more in our guide, How to Use a TDS Meter (and What It Can't Tell You).
Questions? We are here
Not sure what your reading means for your water or your system? Our water specialists have helped customers since 1994. Reach us by phone, email or chat.
Technical specificationsManufacturer material
- Product
- Handheld digital TDS meter, pen style
- Models
- TDS-3 (TDS + temperature); TDS & EC (TDS, EC + temperature)
- TDS & EC: readings
- TDS in ppm, conductivity (EC) in µS/cm, water temperature in °C or °F
- TDS & EC: TDS range
- 0 to 9,999 ppm
- TDS & EC: conductivity range
- 0 to 9,999 µS/cm
- TDS & EC: temperature range
- 0.1 to 80.0 °C (32 to 176 °F)
- TDS & EC: accuracy
- ±5%
- TDS & EC: temperature compensation
- Automatic
- TDS & EC: electrode
- Titanium alloy
- TDS & EC: buttons
- ON/OFF, SHIFT, HOLD
- TDS & EC: auto shut-off
- After 5 minutes with no button pressed
- TDS & EC: memory
- Turns on in the mode you last used
- TDS & EC: size
- 154 x 30 x 14 mm (about 6.1 x 1.2 x 0.6 in)
- TDS & EC: weight
- 45 g (about 1.6 oz), meter only
- TDS & EC: power
- 3V button cell battery
- TDS & EC: marking
- CE
- TDS & EC: max immersion
- 3 cm from the tip (the immersion line); not waterproof
- TDS-3: readings
- TDS in ppm, water temperature
- TDS-3: buttons
- HOLD, TEMP, ON/OFF
- TDS-3: TDS range
- 0 to 9,999 ppm
- TDS-3: resolution
- 1 ppm up to 999 ppm; 10 ppm from 1,000 to 9,999 ppm (shown by the x10 symbol)
- TDS-3: accuracy
- ±2%
- TDS-3: calibration
- Factory calibrated
- TDS-3: temperature range
- 0.1 to 80.0 °C (32 to 176 °F)
- TDS-3: temperature compensation
- Automatic
- TDS-3: size
- 155 x 31 x 23 mm (about 6.1 x 1.2 x 0.9 in)
- TDS-3: weight
- 43 g gross, as printed on the box
- TDS-3: power
- Two 1.5V button cell batteries
- Display
- Digital LCD
- Measures
- Total dissolved solids (estimated from conductivity), water temperature; EC on the TDS & EC model
- Does not measure
- Specific contaminants (lead, PFAS, bacteria, nitrate, pesticides), hardness on its own, pH, chlorine
How to use & careManufacturer material
How to use & care
A reading takes seconds.
- Take off the cap and press ON/OFF.
- Dip the tip into a cup of room-temperature water, no deeper than the immersion line (about 3 cm). Keep the display and buttons dry.
- Stir gently and wait for the reading to settle. The TDS & EC model locks it within 5 seconds.
- Press HOLD, lift the meter out and read it.
- TDS-3: press TEMP for water temperature. TDS & EC: press SHIFT to step through TDS, EC and temperature.
Checking a reverse osmosis system
Read your tap, then your RO faucet, and write both numbers down. Repeat every month or two. When the RO number starts to climb, check your pre-filters and membrane.
The reading guide on the TDS & EC box
- 0 to 50 ppm: high purity
- 51 to 100 ppm: relatively high purity
- 101 to 300 ppm: scale formation
- 301 to 600 ppm: severe scale formation
- 601 to 1,000 ppm: poor taste
- Over 1,000 ppm: unsuitable for drinking
This is the meter maker's general guide. Calcium and magnesium are the main minerals behind scale. A low reading means fewer dissolved solids, but it is not a safety test: a TDS meter cannot detect lead, PFAS, bacteria or nitrate.
Care
- The meter is not waterproof. Never drop it in water or dip it past the immersion line.
- After each test, wipe the tip with a soft cloth and put the cap back on to keep the electrode clean.
- Keep it away from high heat and direct sunlight, and protect it from drops, knocks and heavy pressure.
- The TDS & EC model turns itself off after 5 minutes with no button pressed, to save the battery.
- Take the battery out if you will not use the meter for a long time.
- To check calibration, use a standard calibration solution. Calibrating with the wrong solution makes the readings wrong.
Included parts & replacementsManufacturer material
Parts included
- One Digital TDS Meter, the model you choose
- Protective electrode cap (on the meter)
- Batteries included
What this review is based on.
Elorova researched the public Crystal Quest product listing, its published configuration data, source photographs and linked documents. The source page was checked on .
We have not purchased or installed this product, conducted a laboratory evaluation, or independently confirmed the manufacturer’s treatment and certification claims. We do not copy retailer star ratings into an Elorova rating.
Original Crystal Quest product listingOur research is a snapshot. Check the merchant’s current documentation, warranty, configuration, price and delivery terms before deciding. Read our editorial policy.
