Best EC and TDS Meters: 2026 Buying Guide

The pen most growers should buy: accurate, waterproof, and it reads in whatever units your feed chart uses.

• ±0.1 EC accuracy
• EC, CF and both ppm scales
• Floats
• Factory calibrated

• Automatic temperature compensation, so warm and cold mixes read true
• Backlit screen and a hold button for reading away from the tank
• About 350 hours from one AAA battery

Know before you buyIt switches itself off after 4 minutes, and it costs five times the budget pick.

The cheapest way to stop mixing feed by guesswork and start mixing to a number.

• Digital EC display
• Up to 700 hours’ battery
• Screwdriver calibration
• Carry case included

• Set it against a known solution when the reading drifts
• Tough plastic body for a wet grow room

Know before you buyA strength check rather than a precision instrument. It shows EC only, so test at a similar water temperature each time.

The cheapest pen here with proper specs: temperature compensation, IP65 and a replaceable probe.

• 0.00–10.00 mS/cm
• ±2% full scale
• IP65 waterproof
• Replaceable electrode

• Reads to 0.01 mS/cm
• Automatic temperature compensation from 5 to 50°C
• One-point calibration at 1413 µS/cm with a small trimmer

Know before you buyIt reads mS/cm only, so multiply by 500 or 700 if your feed chart is in ppm.

Stir the tank and read it in one movement, with nothing to calibrate, ever.

• 0.2–3.6 EC
• ±0.1 EC accuracy
• LED scale: EC, CF, ppm
• 5-year warranty

• Factory calibrated for life
• Switches on by itself when the probe touches liquid
• Fully waterproof, with automatic temperature compensation

Know before you buyThe range stops at 3.6 EC and it shows a lit LED, not a number. Long and awkward for a small watering can.

Push the probe into the slab or pot and read EC straight from the medium, with no run-off to collect.

• 0.0–19.9 mS/cm
• 90cm probe cord
• Root-zone temperature
• IP67 electrode

• Shows root-zone temperature to ±0.5°C as well
• Automatic one-point calibration at 1.4 EC
• Replaceable electrode for repeated use

Know before you buyNot the tool for mixing a tank. Readings change with how wet the medium is, so test at the same point after watering.

One meter for pH and EC, with every calibration solution you need in the box.

• pH, EC, TDS, salinity
• pH ±0.01
• IP67
• Replaceable probe

• pH 4 and 7 buffers plus 1413 µS and 12.88 mS EC standards included
• TDS factor adjusts from 0.40 to 1.00 to match your chart
• High and low alarms, auto-hold and a backlit screen

Know before you buyChoose the Hydroponic Meter PRO Kit option. The two cheaper kits on the same page read pH only.