pH + PPM + EC Meters & Solutions

A pH and PPM meter shows exactly what your plants are getting, so you can adjust the feed before lockout shows on the leaves. Pick a combo pen for daily checks, a wall monitor or inline sensor for round-the-clock readings, and fresh calibration solution for either.

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pH + PPM + EC Meters & Solutions

pH and PPM Meter Combos, Pens, Monitors and Calibration Solutions

A pH and PPM meter tells you whether the feed in your reservoir matches the chart, before plants show a problem. This collection covers Bluelab, Hanna, HM Digital, Milwaukee and Myron L meters and pens. Inline sensors from TrolMaster and Growlink, plus calibration and storage solutions, round it out....

pH and PPM meter infographic: combo meters, single testers, inline monitors, ppm 500 vs 700 scales and calibration solutions

For conductivity meters alone, see our TDS, PPM and EC meters. Correct a reading with our pH up and down, and find more water gear in Air + Water + CO2.

Types of Water Testing Meters

Combo Meters and Pens

The Bluelab OnePen reads pH to ±0.05 and EC to ±0.1, with a replaceable probe and Bluetooth logging. The Bluelab Combo Meter shows pH, EC, ppm 500 or ppm 700 and temperature. Hanna's HI98129 reads pH and conductivity to 3999 µS/cm, and it floats. Pick a combo if you check every feed.

Single-Parameter Testers

The Bluelab pH Pen holds ±0.1 pH with a double junction probe and temperature compensation. The Hanna Checker HI98103 reads to 0.1 pH and recognizes 4.01 and 7.01 buffers on its own. For media, the Bluelab Soil pH Pen and Pulse meter read straight in the root zone.

Monitors, Sensors and Solutions

The Bluelab Guardian Inline Wi-Fi logs pH, EC and temperature around the clock. Hanna's GroLine HI981420 reads all three from one probe on the wall. TrolMaster PPH and PCT probes feed controllers. Bluelab, Hanna and GH solutions cover calibration, cleaning and probe storage.

How Growers Use pH and EC Meters

Read the reservoir after mixing nutrients, then again after any pH adjustment, and check runoff. Let calibration solution reach room temperature first. Hanna testers take 1413 µS/cm when they display microsiemens and 1382 ppm when they display ppm.

Frequently Asked Questions

PPM 500 vs 700: which scale should I use?

Use whichever scale your nutrient chart uses. The ppm 500 scale multiplies EC by 500, and ppm 700 by 700, so 2.77 EC reads 1385 or 1939 ppm. Bluelab pens let you choose either. Hanna's HI70442L standard uses a third scale, the 4-4-2 factor of about 0.65.

How often should you calibrate a pH meter?

Plan on about once a month, and sooner if readings drift. Bluelab pH pens show a calibration reminder after 30 days. Use fresh 4.0 and 7.0 solution each time. Conductivity drifts far less, so Bluelab ships those probes factory calibrated and treats 2.77 EC solution as a check.

How to store a pH pen?

Keep the tip wet in KCl storage solution, never dry and never in plain water. RO and distilled water pull potassium chloride out through the junction and shorten probe life. Bluelab puts it simply: if it dries, it dies. Rinse the probe before it goes back in the cap.