General Hydroponics pH Test Kit

The General Hydroponics pH Test Kit provides a simple, economical way to measure the pH of hydroponic nutrient solutions and irrigation water. Its concentrated liquid indicator changes color according to acidity or alkalinity, providing an immediate visual reading without batteries, calibration, or electronic equipment.

The kit covers a broad testing range from approximately pH 4.0 to 8.5. Many hydroponic crops are grown within a nutrient-solution range of approximately 5.5 to 6.5, although the correct target depends on the crop, growing medium, and feeding program.

What’s Included

• Concentrated liquid pH Test Indicator
• Reusable sample vial
• Color-comparison reference chart

Key Benefits

• Wide testing range: Measures nutrient solutions from approximately pH 4.0 to 8.5.
• No calibration required: Provides visual pH testing without maintaining an electronic probe.
• No batteries needed: Always ready for routine reservoir checks.
• Highly concentrated: Only three drops are required for each approximately 5 mL sample.
• Multiple applications: Suitable for nutrient solutions, irrigation water, hydroponic reservoirs, and liquid-feeding programs.
• Useful meter backup: Offers an independent visual reference for checking unexpected digital-meter readings.

How to Test pH

1. Mix all nutrients and compatible supplements completely before collecting the sample.
2. Rinse the test vial with clean water.
3. Fill the vial approximately halfway with about 5 mL of nutrient solution.
4. Add exactly three drops of pH Test Indicator.
5. Gently shake or swirl the vial to mix.
6. Compare the resulting color with the included pH chart under natural or clear, full-spectrum light.
7. Use a white background when comparing colors for easier interpretation.
8. Discard the tested sample and rinse the vial after use.

Important: Test the nutrient solution again after adding pH Up or pH Down. Never add indicator solution directly to a reservoir, and do not return tested samples to the reservoir.

This kit measures pH only. pH Up and pH Down adjusting solutions are sold separately.

Storage

Keep the indicator bottle tightly sealed and store it in a cool, dry location away from direct sunlight and extreme temperatures. Keep out of reach of children and follow the product label and Safety Data Sheet for handling and disposal.