Keep your nutrient readings reliable with Bluelab 2.77 EC Conductivity Standard Solution (500 ml / 16.9 fl oz)—an essential reference solution for calibrating and/or testing conductivity (EC/PPM) probes. Accurate EC measurement helps you maintain consistent nutrient strength, reduce waste, and avoid common feeding problems caused by solutions that are too weak or too strong. Bluelab conductivity standard solutions are manufactured specifically for Bluelab® products and referenced to high laboratory standards, helping your meters and probes stay accurate and perform longer. Combined with regular probe cleaning, this standard solution is one of the simplest ways to improve day-to-day EC/PPM confidence. Key Benefits 2.77 EC standard for checking and maintaining EC/PPM accuracy Ideal for calibrating or testing conductivity probes (where applicable) Helps support consistent feeding and better crop performance Works with all Bluelab® conductivity products Referenced to high laboratory standards for dependable results