Hydroponic pH Tester ------ Unlike Traditional Water Quality Pens, This Product Not Only Measures Ph Ec Tds Temp Easily, But Also Comes with Replaceable Extra-Long, High-Precision Probes To Measure Water Levels In and Narrower Locations.atc Function Provides You with Higher Accuracy and Finer Water Quality.atc Function Provides You with Higher Accuracy and Finer Water Quality Measurements. Perfect for Hydroponics! The Hydroponic EC Meter ------High Accuracy EC Ph Meter Uses A Unique Elongated Probe and Chip To Easily Test The Ec Value of Solutions. It Is Perfect for Hydroponic and Can Be Used To Test The Ph of Nutrient Solutions. Typically, The Optimal Conductivity Range for Hydroponic Is Between 500 and 2000 Ms/cm. The Hydroponic TDS Meter------High Efficiency Tds Detector Makes It Easy To Detect and Control The Tds Value of Hydroponic Solutions for Better Plant Growth. Usually, The Circulating Water System for Vegetable Growing, Hydroponic Tds Value Must Be Less Than or Equal To 1000Mg/l. Root Substrate Ec Value of Tomato, , Etc.: Control At 2.5 To 2.8Ms/cm In Summer and Autumn, The Highest Not Exceeding 3.0Ms/cm, and 3.0 To 3.2Ms/cm In Winter and Spring, The Highest Not Exceeding 3.6Ms/cm; Root Ec Value of Small Cucumber, Coloured Pepper, Etc.: Control At 2.5 To 2.8Ms/cm In Summer and Autumn, The Highest Not Exceeding 3.0Ms/cm; Root Ec Value of Small Cucumber and Coloured Pepper, Etc. Root Ec Value: Summer and Autumn Seasons Control Between 2.2 To 2.5Ms/cm, Do Not Exceed 2.8Ms/cm, Winter and Spring Seasons Control Between 2.5 To 2.8Ms/cm, The Highest Do Not Exceed 3.2Ms/cm That Is The Safe Range. Easy-To-Use Backlit Multifunctional Water Quality Pen------Simply Immerse The Probe In Water and Shake It A Few Times To Easily Obtain Ph, Ec, Tds and Temperature Values. The Backlit Lcd Display Ensures That Measurements Are Clearly Displayed, Even In Dimly Lit Environments, Making Them Easy To Measure and Read. The Included Ph Calibration Powder Helps You To Calibrate The Product and Restore The Accuracy of Your Measurements. Professional and Widely Used Water Quality Tester------This Product Is Very Portable and Suitable for A Wide Range of Measurement Tasks. It Is Suitable for All Hydroponic Growers Such As Nutrient Film Technology, Aeroponics, Etc. It Can Also Be Used To Measure Drinking Water, Wastewater Treatment, Aquarium Culture, Swimming Pools, Hydroponics and More. Model : YY-1040 4 in 1 Hydroponic Test Pen Function: pH; TDS; EC; TEMP pH Range: 0.00-14.00 pH TDS Range: 0-1999ppm; 0-19.9ppt; EC Range: 0-1999uS/cm; 0-19.99mS/cm Calibration:4.00/6.86/;12,88mS/cm;1413uS/cm Resolution : 0.01pH;1ppm(Less than 1999ppm)/10ppm(Greater than1999ppm) ; 1uS/cm(Less than 1999uS/cm)/10uS/( 1999uS/cm) Operation Environment : 0.1-50 Battery: 3 *1.5V LR44 Batteries,Not include Display: LCD Digital Display Backlight: Yes Automatic Temperature Compensation: 0-50 PH Calibration : pH:6.86/4.00, Two Points Waterproof: IP67 The actual product may have slight color differences or differences, which does not affect use. Colour:White Material:plastic Package Contents: 1 x Hydroponic Test Pen Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.