pH, EC, ORP & TDS Calibration Solutions & Buffer Kits
pH, EC, ORP & TDS Calibration Solutions — Keep Every Meter Accurate
A calibration solution is a standardized liquid with a precisely known value used to verify and adjust your measuring instrument to deliver accurate, reliable readings. Without regular calibration, even the best meters drift over time — leading to faulty nutrient mixes, inaccurate water quality reports, and failed quality control checks.
Shop our complete selection of 155+ calibration solutions, buffer solutions, and probe care kits from leading brands including Apera, Bluelab, Milwaukee, Hanna, and more — formulated for professional-grade accuracy across every application.
Calibration Solution Types
- pH Buffer Solutions — pH 4.0, 7.0, and 10.0 buffers for single-point and multi-point pH meter calibration; NIST-traceable accuracy
- EC / Conductivity Standard Solutions — 84 μS/cm, 1,413 μS/cm, 12.88 mS/cm and more for full-range EC and TDS meter calibration
- ORP / Redox Standard Solutions — Quinhydrone or Zobell solutions for accurate ORP meter verification
- TDS Calibration Standards — NaCl and KCl-based solutions in ppm concentrations for TDS meter accuracy
- Dissolved Oxygen (DO) Standards — Zero-oxygen solutions for DO meter span and zero-point calibration
- Ion-Selective Electrode (ISE) Standards — Ionic strength adjustment buffers and standard solutions for nitrate, fluoride, and other ISE probes
Probe Care & Maintenance Accessories
- pH Probe Storage Solutions — KCl-based solutions to keep pH electrodes hydrated between uses and extend probe lifespan
- Probe Cleaning Solutions — Remove protein deposits, mineral scale, and chemical fouling from pH, EC, and DO probes
- Complete Care Kits — All-in-one calibration + storage + cleaning bundles for convenient, comprehensive maintenance
Brands Available
- Apera Instruments — NIST-traceable pH buffer and EC calibration solutions
- Bluelab — EC and pH calibration solutions formulated for Bluelab instruments and general use
- Milwaukee Instruments — Full-range buffer, EC, and ORP calibration solutions and care kits
- Hanna Instruments — Sachets, bottles, and pouches in a wide range of calibration values
How Often Should You Calibrate?
- pH meters: calibrate before each use or at minimum weekly in critical applications
- EC/TDS meters: verify monthly; recalibrate if readings seem inconsistent
- ORP meters: verify with standard solution before each measurement session
- DO meters: calibrate before each use for highest accuracy
Fresh calibration solution is critical — never reuse solutions or return them to the original bottle after use. Browse by brand or solution type below to find exactly what your meter requires.
