pH Calibration Buffer Solution Set pH 4/7/10 & ORP 222mV

Keep your pH and ORP meters reading with precision using this pH Meter Standard Calibration Buffer Solution Set. Whether you're calibrating a digital pH tester for aquariums, hydroponics, water testing, or soil monitoring, this convenient 50ml calibration solution kit delivers repeatable, accurate results every time.

Each set includes standard reference solutions for pH 4.00, pH 7.00, and pH 10.01, plus an ORP 222mV reference solution — covering the full range of calibration needs for most consumer and professional pH/ORP meters. Compact at just 6.6 × 4 × 4 cm (2.59 × 1.57 × 1.57 in), these bottles are easy to store in your testing kit or lab drawer. Available in 4 color-coded options to help you quickly identify each buffer value at a glance.

Key Features

• Multi-Point Calibration: Supports pH 4.00, 7.00, and 10.01 buffer points for accurate span and offset calibration
• ORP Reference Solution: 222mV standard for reliable oxidation-reduction potential meter calibration
• Compact & Portable: Small 50ml bottles fit neatly in any testing kit or storage drawer
• Color-Coded Options: Choose from 4 color variants for easy identification
• Wide Compatibility: Works with most digital pH meters and ORP testers on the market
• Everyday Value: Reliable, consistent reference solutions at an accessible price point

Ideal Applications

• Aquarium and fish tank water quality monitoring
• Hydroponic and soil nutrient testing
• Drinking water and pool/spa water testing
• Laboratory and classroom science use
• Home brewing and fermentation

Product Specifications

For guidance on water quality testing standards and best practices, visit the U.S. Environmental Protection Agency – Ground Water and Drinking Water resource.

Frequently Asked Questions

Q: What pH calibration buffer solutions are included in this set?

A: This calibration solution set covers the three most widely used pH reference points — pH 4.00, pH 7.00, and pH 10.01 — plus an ORP 222mV standard solution, making it suitable for multi-point calibration of digital pH and ORP meters.

Q: How do I use pH calibration buffer solution to calibrate my meter?

A: Rinse your pH meter's electrode with distilled water, then immerse it in the appropriate buffer solution (e.g. pH 7.00 first). Adjust your meter to match the reference value, rinse again, and repeat with the second buffer point for a two- or three-point calibration. Always follow the specific instructions for your meter model.

Q: Are these calibration solutions compatible with all pH meters?

A: Yes — these standard buffer solutions are compatible with the vast majority of consumer and professional digital pH meters and ORP testers available on the market, as they conform to internationally recognized pH reference values (pH 4.00, 7.00, 10.01) and ORP standard (222mV).

Q: How should I store these calibration buffer solutions?

A: Store the bottles in a cool, dry location away from direct sunlight and extreme temperatures. Keep caps tightly sealed when not in use to prevent evaporation or contamination, which could affect accuracy.