Methylene Blue, 1% USP (Pharmaceutical) Grade: 2×50 mL Twin Pack Glass: 3rd Party Tested

Conductivity Standard 2-Pack — 250 mL (8.4 fl oz) Each: 100 μS and 1413 μS — NIST Traceable — for 2-Point Calibration

Methylene Blue, 1% USP (Pharmaceutical) Grade, 50 mL (1.69 fl oz) Glass; 3rd Party Tested

pH Buffer Calibration Solution Kit 2-Pack — one pH 4.00 (red) and one pH 7.00 (Yellow), Each 500 mL (1.06 Pint) — NIST Traceable Reference Standards for All pH Meters

pH/Oxygen Reduction Potential (ORP) Electrode Storage Solution, 250 mL (8.4 fl oz) — Suitable for All pH Meters — 1M KCl Solution — Keeps Your Probe Conditioned and Helps to Extend its Life

pH Buffer Calibration Kit 2-Pack: pH 4.00 and pH 7.00, 500 mL (1.06 Pint) Each — for Precise and Accurate Calibrations — Designed for Hydroponics and Aquaponics — Ideal for All pH Meters

Biopharm pH Buffer Calibration Solution Kit (3) 250 ml (8oz) Bottles pH 4.00, pH 7.00 and Electrode Storage Solution NIST Traceable Reference Standards for All pH Meters

Biopharm Triton X-100 Surfactant (500 mL) | Nonionic Surfactant | Laboratory Cleaning Detergent | Not Diluted

Phenolphthalein Powder Certified ACS Reagent Grade 100 Grams