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 Deeper 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 Aqueous Solutions. It Is Perfect for Hydroponic Crops and Can Be Used To Test The Ph of Nutrient Solutions. Typically, The Optimal Conductivity Range for Hydroponic Crops 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