Best pH Meters for Hydroponics: 2026 Buying Guide

Everything a reservoir pen needs at a sensible price: temperature compensation, IP67 and automatic calibration.

• ±0.1 pH
• Auto 2-point calibration
• ATC 0–50°C
• IP67

• Replaceable electrode, so the pen outlives its probe
• Arrives calibrated, with a 30-day calibration reminder
• Reads pH and temperature together

Know before you buyAt 230mm and 132g it is chunkier than most pens, and it switches itself off after 8 minutes.

A basic pen you can calibrate from day one, for checking a watering can of feed.

• 0.0–14.0 pH
• CAL button
• 3 buffer powders included
• Protective cap

• The cheapest pen here, and it calibrates
• pH 4.00, 6.86 and 9.18 buffer powders in the box
• Pocket-sized, with a storage case

Know before you buyA basic pen: calibrate it often, and keep it away from a busy reservoir.

The cheapest pen here that is both waterproof and repairable.

• ±0.1 pH
• IP65
• Replaceable electrode
• 1 or 2-point calibration

• Over 1,500 hours of battery life
• Two-year warranty, six months on the electrode
• Large display, easy to read over a tank

Know before you buyCalibration is set by hand with small trimmers rather than automatically, which takes a little practice.

The most precise pen here at ±0.01 pH, and it floats if you drop it in the tank.

• ±0.01 pH
• Auto 1, 2 or 3-point calibration
• ATC 0–50°C
• IP67, floats

• Recognises both common buffer sets
• Replaceable double-junction probe
• Buffer sachets, measuring cup and batteries in the box

Know before you buyThe second decimal only counts with careful calibration and fresh buffer. It will not change how you feed.

A pen you repair rather than replace: when the probe wears out, you screw in a new one.

• ±0.1 pH
• Replaceable probe
• IP68
• pH and temperature

• Two-point calibration with a 30-day reminder
• Calibration and KCl storage sachets in the box
• Two-year warranty, six months on the probe

Know before you buyRated for solutions of 0.2 EC and above, so it is not the tool for checking pure RO water.

pH, EC and temperature from one dip, for growers who check both at every feed.

• pH and EC ±0.1
• EC factory-calibrated
• Automatic temperature compensation
• 5-year meter warranty

• Reads EC, CF, ppm 500 or ppm 700
• Only the pH side needs a monthly two-point calibration
• Backlit display for dim tents

Know before you buySplash-resistant, not waterproof, and it costs more than Bluelab’s separate pH and EC pens together (£160.44).

Watches the reservoir around the clock and sends alarms to your phone.

• Live pH, EC and temperature
• High and low alarms
• Wi-Fi, Edenic app
• Mains powered

• Probes hang in the tank on 2m cables
• Settings and calibration survive a power cut
• Plant-safe green display with adjustable brightness

Know before you buyIt monitors but does not dose, and conductivity tops out at 5.0 EC.