Tds Meter Arduino: Performance, Specifications, and How to Apply It in Industry

Types of TDS Meter Arduino

A TDS Meter Arduino is an electronic water quality monitoring system built using the Arduino microcontroller platform. Total Dissolved Solids (TDS) meters measure the concentration of dissolved ions in water, which helps assess purity, salinity, or suitability for drinking, hydroponics, aquariums, and industrial applications. These systems vary widely in design and functionality based on their hardware integration and communication capabilities.

Below is a detailed breakdown of the most common types of TDS meter Arduino configurations, each tailored for specific use cases—from basic educational projects to advanced IoT-enabled monitoring systems.

TDS Meter Arduino with LCD Display

This configuration integrates an LCD (Liquid Crystal Display) module to show real-time TDS and temperature readings directly on the device. It's ideal for standalone applications where immediate visual feedback is needed without a computer or smartphone.

Advantages

• Real-time display without external devices
• User-friendly interface for non-technical users
• Low power consumption and portable setup
• Easy to assemble with common components (e.g., 16x2 LCD)

Limitations

• Limited data logging capability
• No remote access or connectivity
• Screen visibility issues in bright sunlight

Best for: Educational kits, home water testing, portable field testing

TDS Meter Arduino with Bluetooth

This model uses a Bluetooth module (such as HC-05 or HC-06) to wirelessly transmit TDS and temperature data to smartphones or tablets. Users can view readings via custom Android/iOS apps, enabling convenient monitoring without physical access to the device.

Advantages

• Wireless real-time data transmission
• Compatible with mobile apps for visualization
• Greater mobility and ease of use
• Simple integration with existing phone-based dashboards

Limitations

• Short-range connectivity (~10 meters)
• Requires paired device nearby
• Battery drain due to constant Bluetooth use

Best for: Smart home systems, aquarium monitoring, mobile diagnostics

Analog TDS Meter Arduino

This basic version uses an analog TDS sensor that outputs a voltage proportional to the water’s conductivity. The Arduino reads this analog signal through its ADC (Analog-to-Digital Converter) and converts it into TDS values (typically in ppm).

Advantages

• Simplified circuit design
• Low cost and widely available components
• Great for beginners and prototyping
• Minimal power requirements

Limitations

• Less accurate without calibration
• Susceptible to electrical noise
• Lacks digital filtering by default

Best for: DIY projects, learning electronics, entry-level water testing

TDS Meter Arduino with Wi-Fi

Equipped with a Wi-Fi module like ESP8266 or ESP32, this advanced model uploads TDS and temperature data to cloud platforms (e.g., ThingSpeak, Blynk, or AWS). It enables remote monitoring, historical data tracking, and automated alerts.

Advantages

• Internet-based remote monitoring
• Integration with IoT ecosystems
• Data logging and trend analysis
• Supports email/SMS alerts for threshold breaches

Limitations

• Higher power consumption
• More complex setup and coding
• Dependent on stable internet connection

Best for: Industrial monitoring, hydroponic farms, laboratory environments, smart agriculture

TDS and Temperature Meter

This dual-sensor configuration simultaneously measures both TDS and water temperature. Since TDS readings are temperature-dependent, having accurate temperature data allows for proper compensation and improved measurement accuracy.

Advantages

• Temperature-compensated TDS readings
• Higher accuracy and reliability
• Single-unit convenience for two critical parameters
• Essential for scientific and industrial applications

Limitations

• Requires additional sensor (e.g., DS18B20 or thermistor)
• More complex wiring and calibration
• Slightly higher cost than basic models

Best for: Hydroponics, aquariums, water treatment systems, environmental monitoring

Type	Connectivity	Accuracy	Best Use Case	Complexity
TDS Meter with LCD	Local Display	Medium	Portable testing, education	Low
TDS Meter with Bluetooth	Short-range Wireless	Medium-High	Mobile monitoring, smart homes	Medium
Analog TDS Meter	Wired (Analog Output)	Low-Medium	Beginner projects, prototyping	Low
TDS Meter with Wi-Fi	Internet (IoT)	High	Remote monitoring, automation	High
TDS & Temperature Meter	Local or Connected	High	Scientific, agricultural use	Medium

Expert Tip: Always calibrate your TDS sensor using a known standard solution (e.g., 1413 µS/cm or 1000 ppm) and ensure temperature compensation is enabled—especially when using the TDS and Temperature Meter variant—for the most accurate results.

Industry Applications of TDS Meter Arduino

An Arduino-based TDS (Total Dissolved Solids) meter is a versatile, cost-effective solution for real-time water quality assessment across diverse industries. By measuring the concentration of dissolved ions in water, these devices provide critical insights into water purity, nutrient balance, and environmental health. Their open-source nature allows for customization, integration with IoT systems, and scalable deployment—making them ideal for both small-scale projects and large industrial monitoring networks.

Key Industry Applications

Water Quality Monitoring

Arduino TDS meters are extensively used to monitor potable water in municipal supplies, residential systems, and industrial facilities. These systems enable continuous, real-time tracking of water purity without altering its chemical composition.

Large-scale industries such as pharmaceuticals, semiconductor manufacturing, and food processing use custom-built Arduino TDS monitoring systems to ensure compliance with safety standards, prevent contamination, and automate alerts when thresholds are exceeded. This proactive monitoring helps maintain consistent product quality and regulatory compliance.

Hydroponics and Soil-less Agriculture

In hydroponic farming and vertical agriculture, precise control of nutrient solutions is essential for optimal plant growth. TDS levels directly correlate with the concentration of essential nutrients like nitrogen, potassium, and phosphorus dissolved in the water.

Arduino-based TDS sensors allow growers to monitor and adjust nutrient dosages automatically, preventing both deficiencies and toxicities. Integration with microcontrollers enables smart irrigation systems that deliver the right nutrient mix at the right time, significantly improving crop yield and resource efficiency.

Aquaculture and Fish Farming

Water quality is a determining factor in the health and survival of aquatic species such as fish, shrimp, and mollusks. Fluctuations in TDS can indicate changes in salinity, mineral content, or pollutant levels, all of which affect osmoregulation and gill function in aquatic organisms.

Arduino TDS meters provide aquaculture operators with real-time data to maintain ideal water conditions. When paired with pH and temperature sensors, they form a comprehensive monitoring system that supports early detection of stress conditions, reduces mortality rates, and enhances productivity in commercial fish and shrimp farming operations.

Industrial Process Control

Many industrial processes—from boiler feedwater in power plants to rinsing stages in food and beverage production—require strict control over water quality. High TDS levels can lead to scaling, corrosion, and inefficiencies in heat transfer systems.

By integrating Arduino TDS meters into process control loops, industries can automate water treatment systems, optimize reverse osmosis (RO) performance, and improve water reuse strategies. This not only extends equipment lifespan but also reduces operational costs and environmental impact through sustainable water management.

Environmental Research and Monitoring

Environmental scientists rely on TDS as a key indicator of water body health, pollution levels, and ecosystem stability. Changes in TDS can signal runoff from agricultural lands, industrial discharges, or natural geological processes.

Portable Arduino TDS meters empower field researchers to collect accurate, geo-tagged data in remote locations. Their low cost and adaptability make them ideal for large-scale environmental studies, watershed assessments, and long-term ecological monitoring programs, supporting data-driven conservation efforts.

Health and Fitness Sector

In the health and wellness industry, water quality directly impacts human hydration and mineral intake. Consumers and health professionals use TDS meters to evaluate drinking water—from tap water to bottled and mineral water—ensuring it contains beneficial minerals while avoiding excessively purified or contaminated sources.

Arduino-based TDS testers are used in fitness centers, clinics, and homes to educate individuals about water quality. They help promote informed choices about hydration, support dietary planning, and raise awareness about the importance of balanced mineral content in daily water consumption.

Industry	Primary Use Case	Benefits of Arduino TDS Meters
Water Treatment	Continuous quality monitoring	Real-time alerts, low-cost deployment, easy integration with SCADA systems
Hydroponics	Nutrient solution management	Precise dosing, automation, improved crop yields
Aquaculture	Water condition stability	Reduced mortality, early warning system, scalability
Manufacturing	Process water control	Prevents scaling, reduces downtime, supports sustainability
Environmental Science	Field data collection	Portability, affordability, customizable logging
Health & Wellness	Drinking water assessment	Consumer education, transparency, health optimization

Why Choose Arduino-Based TDS Solutions?

Cost-Effective: Significantly cheaper than commercial analyzers, ideal for startups and educational institutions.

Customizable: Open-source platform allows integration with displays, cloud platforms, alarms, and other sensors (pH, temperature, EC).

Portable & Scalable: Can be deployed as handheld testers or networked across multiple locations for large-scale monitoring.

Educational Value: Widely used in STEM programs to teach water chemistry, electronics, and programming.

Sustainability Support: Enables water recycling, reduces waste, and promotes responsible resource use across industries.

Note: While Arduino TDS meters provide reliable relative measurements, they should be calibrated regularly using standard solutions for accuracy. They measure electrical conductivity and estimate TDS based on a conversion factor, so results may vary slightly depending on ion composition. For regulatory or compliance purposes, always cross-check with laboratory-grade equipment when required.

Product Specifications and Features of TDS Meter Arduino

A TDS (Total Dissolved Solids) meter based on the Arduino platform is a powerful, flexible, and cost-effective solution for monitoring water quality in various applications—from hydroponics and aquariums to environmental research and industrial water treatment. Unlike traditional commercial meters, Arduino-based TDS meters offer open-source adaptability, real-time monitoring, and seamless integration with other sensors. Understanding their technical specifications and key features helps users make informed decisions when building or selecting a system tailored to their needs.

Measurement Range

TDS meters typically measure dissolved solids in water from 0 to 1000 ppm (parts per million), which is equivalent to mg/L. This range is suitable for most household, agricultural, and educational applications.

• Higher-end models designed for laboratory or industrial use can extend up to 2000 ppm or more, accommodating brackish or saline water testing.
• The sensor's accuracy may vary at extreme ends of the scale, so proper calibration is essential for reliable results.
• Arduino-based systems often use analog voltage conversion to calculate TDS values, requiring precise code implementation for correct scaling.

Note: Always verify the sensor module’s specified range before deployment to avoid inaccurate readings.

Measurement Units and Conversion

TDS levels are commonly displayed in ppm or mg/L, but conductivity is measured in microsiemens per centimeter (µS/cm). The Arduino TDS meter converts conductivity readings into TDS using an empirical formula (often TDS ≈ 0.5 × EC).

• Analog TDS sensors output a voltage signal (typically 0–5V or 3.3V) that must be converted to digital values via the Arduino’s ADC (Analog-to-Digital Converter).
• Software libraries and calibration curves allow users to switch between units depending on regional standards or application requirements.
• For scientific consistency, advanced setups may include automatic temperature compensation (ATC) since conductivity varies with water temperature.

Pro tip: Use a temperature sensor (e.g., DS18B20) alongside the TDS probe for more accurate EC-to-TDS conversions.

Calibration Process

Calibration ensures measurement accuracy by aligning the sensor output with known standard solutions (commonly 1413 µS/cm or 1000 ppm).

• Many Arduino-compatible TDS modules support manual calibration through code adjustments or potentiometer tuning.
• Some advanced systems implement automatic calibration routines triggered by user input or scheduled intervals.
• Regular recalibration (every 1–2 weeks) is recommended, especially after prolonged use or exposure to contaminated water.

Best practice: Store calibration data in EEPROM to retain settings across power cycles.

Power Supply Options

Arduino TDS meters are designed for flexibility in power sources, making them ideal for both portable and fixed installations.

• Most hobbyist setups run on 9V batteries or USB power via an Arduino Uno or Nano.
• Industrial or remote monitoring systems may use rechargeable lithium-ion batteries paired with solar chargers.
• Low-power modes and sleep functions help extend battery life in field-deployed units.

Energy-saving tip: Implement duty cycling—activate the sensor only during readings—to reduce power consumption and prolong probe life.

Data Logging Capabilities

Advanced Arduino TDS meters can record water quality data over time, enabling trend analysis and long-term monitoring.

• Add an SD card module to log TDS, temperature, and timestamp data at user-defined intervals (e.g., every 5 minutes).
• Integrate with I2C RTC (Real-Time Clock) modules for accurate time-stamping of measurements.
• Data logging is essential for environmental studies, aquaculture management, and compliance reporting.

Application example: A farm using hydroponics can analyze weekly TDS trends to optimize nutrient dosing.

Build Quality and Durability

While commercial TDS meters come in rugged enclosures, DIY Arduino versions require careful assembly for longevity.

• Use waterproof probes and sealed enclosures to protect electronics from moisture and corrosion.
• Choose high-quality TDS sensor modules with built-in amplifiers and noise filters for stable readings.
• Regular cleaning of the probe with distilled water prevents mineral buildup and drift in readings.

Maintenance note: Replace TDS probes every 1–2 years depending on usage frequency and water conditions.

Key Features of Arduino-Based TDS Meters

Innovation Advantage: The open-source nature of Arduino allows users to customize every aspect of the TDS meter—from hardware design to data visualization—making it a superior choice for education, research, and smart agriculture.

• Simplicity and Convenience: Arduino TDS meters are user-friendly and require minimal technical expertise to assemble and operate. With plug-and-play modules and readily available code examples, even beginners can set up a functional system within hours. Real-time readouts eliminate the need for lab testing, enabling immediate decision-making in the field.
• Low Cost: Compared to commercial meters that can cost hundreds of dollars, a complete Arduino TDS setup (board, sensor, display) can be built for under $50. This affordability makes continuous water monitoring accessible for schools, small farms, and community projects.
• Customization: Users can modify firmware to adjust sampling rates, add alarms for threshold breaches, or integrate machine learning algorithms for predictive analysis. Hardware can be expanded with LCD screens, Wi-Fi modules (ESP8266/ESP32), or relay controls for automated water treatment systems.
• Open Source: The Arduino ecosystem provides vast community support, free libraries (e.g., TDS_Sensor, OneWire), and detailed tutorials. This transparency fosters innovation and learning, empowering users to understand and improve their systems.
• Portability: Compact designs powered by batteries or power banks make Arduino TDS meters ideal for on-site testing in remote locations—rivers, wells, greenhouses, or disaster zones—without relying on grid electricity.
• Integration with Other Sensors: One of the biggest advantages is the ability to combine the TDS sensor with pH, ORP, dissolved oxygen, turbidity, and temperature sensors on a single platform. This enables comprehensive water quality assessment, crucial for applications like aquaponics, wastewater monitoring, and ecological research.

Feature	Arduino-Based TDS Meter	Commercial TDS Meter	Advantage
Cost	$20–$60	$100–$500+	Significant savings for DIY users
Customizability	High (code & hardware modifiable)	Low (fixed firmware)	Full control over functionality
Integration	Easy with multiple sensors	Limited or proprietary	Better for multi-parameter analysis
Data Logging	Expandable with SD/Wi-Fi	Often built-in	Flexible storage options
Portability	High (lightweight, battery-powered)	Variable	Ideal for fieldwork

Additional Considerations

• Temperature Compensation: Since TDS readings depend on water temperature, always use a temperature sensor for accurate results. Most algorithms apply a 2% per °C correction factor.
• Sensor Maintenance: Clean the probe regularly with soft brush and distilled water to prevent fouling and ensure consistent performance.
• Code Optimization: Use floating-point math carefully on 8-bit Arduinos; consider fixed-point arithmetic for faster processing.
• Wireless Connectivity: Add ESP32 or NRF24L01 modules to transmit data to cloud platforms like Blynk, ThingSpeak, or MQTT servers.
• Educational Value: Building an Arduino TDS meter teaches principles of electronics, programming, chemistry, and environmental science—making it perfect for STEM curricula.

Professional Recommendation: For reliable, long-term deployments, invest in a high-quality TDS sensor module with built-in signal conditioning and pair it with an Arduino board that supports sleep modes and data logging. Combine it with a waterproof enclosure and solar charging for off-grid applications. Whether you're monitoring hydroponic nutrients, testing drinking water, or conducting environmental research, the Arduino TDS meter offers unmatched flexibility and value.

How To Choose the Right TDS Meter for Arduino Projects

Selecting the appropriate Total Dissolved Solids (TDS) meter for your Arduino-based water quality monitoring system is crucial for reliable and accurate measurements. Whether you're building a smart irrigation system, a hydroponics controller, or a laboratory-grade water analyzer, understanding the key selection criteria ensures optimal performance and longevity. This guide breaks down the essential factors to consider when choosing a TDS sensor module compatible with Arduino platforms.

Important Note: TDS meters do not directly measure dissolved solids. Instead, they estimate TDS by measuring water's electrical conductivity and applying a conversion algorithm. Accuracy depends heavily on proper calibration, temperature compensation, and sensor maintenance.

Key Factors When Choosing a TDS Meter for Arduino

• Accuracy and Measurement Range

  Accuracy is one of the most critical specifications for any TDS meter. High-quality sensors typically offer ±2% to ±5% accuracy, while budget models may have higher error margins. The measurement range should match your application:

  • Laboratory & Industrial Use: Look for meters with a broad range (e.g., 0–9990 ppm) and high precision for analyzing diverse water sources like wastewater, seawater, or chemical solutions.
  • Home & Garden Applications: For aquariums, hydroponics, or drinking water, a range of 0–2000 ppm is usually sufficient, with emphasis on accuracy in lower ranges where subtle changes matter most.
  • Temperature Compensation: Ensure the sensor includes Automatic Temperature Compensation (ATC), as conductivity—and thus TDS readings—varies significantly with temperature.
• Sensor Quality and Design

  The sensor is the heart of your TDS meter, directly influencing reliability and lifespan. High-performance sensors use corrosion-resistant materials like titanium or platinum-coated electrodes to resist fouling and degradation.

  • Industrial-grade sensors offer faster response times and better stability over extended use.
  • Cheap sensors often use lower-grade metals that oxidize quickly, especially in high-TDS or chlorinated water, leading to drift and inaccurate readings.
  • Proper housing (e.g., epoxy-sealed bodies) protects internal circuitry from moisture and physical damage, enhancing durability and safety.
  • Consider replaceable probe designs for long-term projects to reduce maintenance costs.
• Power Source and Efficiency

  Most Arduino-compatible TDS modules operate on 3.3V to 5V DC, drawing power from the microcontroller or an external supply. Power efficiency becomes critical in battery-powered or remote monitoring setups.

  • Low-power sensors with sleep modes can extend battery life significantly—ideal for field deployments or IoT devices.
  • Modules with continuous display, backlighting, or real-time data logging consume more power and may require external power banks or solar charging systems.
  • Look for modules with enable pins that allow software control of power to the sensor, reducing energy consumption when not in use.
• Build Quality and Environmental Durability

  Durability is essential, especially for outdoor or industrial applications. Evaluate the sensor’s ingress protection (IP) rating:

  • An IP67 rating means the device is dust-tight and can withstand temporary immersion in water—ideal for harsh environments.
  • Stainless steel housings provide superior resistance to corrosion and mechanical impact compared to plastic enclosures.
  • For permanent installations, consider waterproof cable glands and UV-resistant materials if exposed to sunlight.
• Display Type and Readability

  While many Arduino TDS systems output data to serial monitors or external displays, some integrated modules feature built-in screens.

  • Digital Displays (LCD/LED): Offer clear, precise readings and can show additional data such as temperature, time, and units (ppm, mg/L, µS/cm).
  • Backlit Screens: Improve visibility in low-light conditions, while transflective LCDs remain readable under direct sunlight.
  • In custom builds, pairing the sensor with an I2C OLED or TFT display gives flexibility in interface design and user interaction.
• Data Logging and Connectivity Options

  Advanced TDS meters enhance functionality through data storage and communication capabilities, making them ideal for long-term monitoring and analysis.

  • Data Logging: Modules with SD card support can record measurements at set intervals for later retrieval and trend analysis.
  • USB Interface: Enables direct connection to PCs for real-time monitoring and firmware updates.
  • Wireless Connectivity: Bluetooth or Wi-Fi-enabled sensors (e.g., via ESP32 integration) allow remote access through mobile apps or cloud platforms like Blynk, ThingSpeak, or Home Assistant.
  • Open-source libraries and example code (available on GitHub or Arduino IDE) simplify integration with your project.

Selection Criteria	Ideal for Hobbyists	Suitable for Professionals	Recommended Features
Accuracy	±5% F.S.	±2% F.S. or better	Calibration support, ATC
Range	0–2000 ppm	0–9990 ppm	Multi-range auto-detection
Sensor Material	Stainless steel	Titanium or platinum-coated	Corrosion-resistant, replaceable probe
Power Consumption	5–10 mA	<5 mA (sleep mode)	Enable pin, low-power mode
Connectivity	Serial/I2C output	Wi-Fi/Bluetooth, SD logging	Cloud integration, real-time dashboard
Durability	Basic waterproofing	IP67 rated, stainless housing	UV-resistant, sealed electronics

Expert Tip: Always calibrate your TDS sensor regularly using standard calibration solutions (e.g., 1413 µS/cm or 12.88 mS/cm). Drift over time is common, especially after prolonged use or exposure to extreme conditions. A monthly calibration schedule ensures consistent accuracy and reliable data collection.

Additional Recommendations

• Choose modules with clear documentation and Arduino library support to speed up development.
• Use protective caps or storage solution when the probe is not in use to prevent drying and contamination.
• Regularly clean the sensor with distilled water and soft brush to remove mineral buildup.
• Combine TDS sensing with pH and temperature sensors for comprehensive water quality analysis.
• For critical applications, implement redundant sensors or periodic manual verification.

Selecting the right TDS meter for your Arduino project involves balancing performance, cost, and environmental demands. By focusing on accuracy, sensor quality, power efficiency, and connectivity, you can build a robust system tailored to your specific needs—whether it's monitoring a home aquarium or managing industrial water treatment processes. With proper care and calibration, your TDS sensor will deliver reliable data for years to come.

Frequently Asked Questions About TDS in Drinking Water

Q1: What is TDS in drinking water?

A1: Total Dissolved Solids (TDS) refers to the combined content of all inorganic and organic substances dissolved in water at a molecular, ionized, or micro-granular suspended level. These include minerals (like calcium, magnesium, and potassium), salts (such as chlorides and sulfates), and trace amounts of organic matter.

According to the Natural Resources Defense Council (NRDC), the ideal TDS level for drinking water is around 200 parts per million (ppm). Water with excessively high TDS (>1000 ppm) may taste salty, bitter, or metallic and can leave deposits on fixtures. Conversely, water with very low TDS (<50 ppm), such as distilled or reverse osmosis-filtered water, may taste flat or bland and lack essential minerals beneficial for health.

The World Health Organization (WHO) classifies water with TDS below 300 ppm as excellent for drinking, while levels above 1200 ppm are considered unpalatable by most consumers.

Q2: How does a TDS meter work?

A2: A TDS meter estimates the concentration of dissolved solids by measuring the electrical conductivity (EC) of water. Since pure water is a poor conductor of electricity, any dissolved ions—such as sodium, chloride, calcium, or magnesium—increase its ability to conduct an electric current.

The meter uses two or more electrodes to pass a small electrical current through the water sample and measures the resistance. Based on this conductivity reading, it applies a conversion factor (typically between 0.5 and 0.7) to estimate the TDS value in parts per million (ppm).

For example, if the conductivity is 500 µS/cm and the conversion factor is 0.67, the estimated TDS would be approximately 335 ppm. It's important to note that TDS meters do not identify specific contaminants—they provide a general estimate of total dissolved ions.

Q3: Can a TDS meter measure TDS in pure water?

A3: True pure water (deionized or distilled) has virtually no dissolved ions and should register a TDS close to 0 ppm. However, most TDS meters may display a reading of 1–2 ppm due to minimal atmospheric CO₂ dissolving into the water (forming weak carbonic acid) or trace contamination from the container or sensor.

TDS meters are not designed to accurately measure ultra-pure water because their sensitivity range typically starts around 10–50 ppm. For laboratory-grade purity assessment, more advanced tools like resistivity meters are used instead.

In practical applications, TDS meters are most effective for testing tap water, bottled water, filtered water (e.g., from reverse osmosis systems), and mineral water, where dissolved solids are present in measurable quantities.

Q4: How do you calibrate a TDS meter?

A4: Calibrating a TDS meter ensures accurate and reliable readings. The process involves using standardized calibration solutions with known TDS concentrations—commonly 1413 ppm or 1000 ppm solutions made from potassium chloride (KCl).

Here’s a step-by-step guide:

1. Prepare the calibration solution: Use a fresh, unexpired standard solution stored in a clean container.
2. Clean the probe: Rinse the meter’s sensor with distilled water and gently blot dry.
3. Immerse the probe: Place the sensor fully into the calibration solution, avoiding air bubbles.
4. Adjust the reading: Turn on the meter and wait for stabilization. Use the calibration screw or digital button (depending on model) to adjust the display to match the known value of the solution.
5. Verify accuracy: Optionally, test a second standard solution (e.g., 1413 ppm and 1000 ppm) to confirm linearity across the range.
6. Rinse and store: After calibration, rinse the probe with distilled water and store it according to the manufacturer’s instructions.

Regular calibration—recommended every 1–3 months or after heavy use—ensures long-term accuracy, especially for meters used in quality control, aquariums, hydroponics, or water treatment systems.

Q5: What are the health and practical risks of high TDS in water?

A5: While high TDS itself is not always directly toxic, it can indicate the presence of undesirable minerals, salts, or contaminants that affect both water quality and health. Elevated TDS levels (above 1000 ppm) pose several risks:

• Poor taste and odor: High concentrations of minerals like iron, manganese, or sulfates can make water taste metallic, salty, or rotten-egg-like, discouraging adequate hydration and potentially leading to dehydration.
• Digestive issues: Consuming water with excessive sulfate or magnesium can cause laxative effects, leading to diarrhea, especially in sensitive individuals or travelers unaccustomed to local water.
• Mineral imbalance: Chronic intake of water high in calcium and magnesium (hard water) may contribute to kidney stone formation in predisposed individuals. Similarly, elevated sodium levels can be problematic for people with hypertension or heart conditions.
• Appliance scaling: High TDS contributes to limescale buildup in kettles, water heaters, and pipes, reducing efficiency and lifespan of household appliances.
• Corrosion: Water with high conductivity due to dissolved salts can be corrosive to plumbing, potentially leaching metals like lead or copper into the water supply.

The U.S. Environmental Protection Agency (EPA) sets a secondary (non-enforceable) standard for TDS at 500 ppm for aesthetic reasons. For optimal health and taste, it's advisable to use filtration methods like reverse osmosis, distillation, or deionization when TDS exceeds 500–600 ppm.