pH and EC meters and controllers

Reference values for pH and EC

Measure pH after mixing in the nutrients, because they shift it. Then correct with small doses of BioBizz pH Plus or pH Minus (1 L or 5 L), stir and measure again.

Pens, monitors and controllers: the differences

• Handheld meters: for checking water and reservoir by hand. The Bluelab Combo Meter and Aquamaster P160 Combo Pen measure pH and EC in one device; the Bluelab EC Truncheon measures EC only. The range is completed by the Aquamaster P50, P700, H600 and Milwaukee MC110.
• Growing medium pH: the Aquamaster S300 measures pH directly in the growing medium, handy in soil.
• Monitors: the Bluelab Guardian Monitor, also available with Wi-Fi, stays in the reservoir and shows readings continuously; ideal for irrigation systems and hydro set-ups with a reservoir.
• Controllers: the Bluelab pH Controller and Controller Connect measure pH in the reservoir and dose the corrector automatically. Worth it for large reservoirs or systems that are not checked every day.

Calibration and probe care

1. Calibrate pH with pH 7.0 and pH 4.0 buffer solutions, fresh and at room temperature.
2. Repeat calibration every 2–4 weeks, and straight away if readings become slow or unstable.
3. Keep the pH probe moist in storage solution: never dry and never in distilled water.
4. Check EC with the reference solution specified by the manufacturer and rinse the probes with clean water after every reading.

To automate climate and irrigation as well, have a look at the controllers.

Delivery and advice

All prices are in Swiss francs including Swiss VAT. Gro.w.LaB ships throughout Switzerland with Swiss Post; bulky parcels travel by courier. We can recommend the right instrument for your system, from pen to controller. For technical advice, send us an email or call +41 79 359 67 58; you are welcome at our Quartino shop by appointment.

Useful guides

• Water pH: the right levels for soil, coco and hydro
• Nutrients: NPK, doses and EC for veg and flowering
• Hydroponics: systems and first steps

Frequently asked questions

What pH should water be for soil, coco and hydro?

Soil 6.0–7.0; coco and hydro 5.5–6.5. Always measure after adding the nutrients.

How do I calibrate a pH meter?

Rinse the probe, dip it first in pH 7.0 buffer solution and then in pH 4.0, confirming each point as described in the manual.

How often should a pH probe be calibrated?

Every 2–4 weeks with regular use, and whenever readings become slow or unstable.

What is EC and what value should I aim for?

EC (electrical conductivity) shows how much nutrient salt the solution contains, in mS/cm. Guide values: 0.4–0.8 for seedlings and cuttings, 0.8–1.6 in veg, 1.2–2.0 in flowering.

How do I raise or lower pH?

With pH correctors: pH Plus to raise it, pH Minus to lower it. Add a little at a time, stir and measure again.