Bluelab One Pen - All-in-One pH, EC and Temperature Handheld
Best for: growers who want Combo Meter-style all-in-one readings but in a single streamlined pen rather than a probe-on-a-cable design.
Our thoughts
Think of this as Bluelab's take on the combo meter in a tidier, single-pen body. It measures pH, conductivity and temperature from one sensor tip, so you get the same "one dip, all the numbers" convenience without a separate cable and display unit to keep track of.
The Bluelab One Pen is an all-in-one portable meter that reads pH, conductivity (in EC, CF, PPM 500 or PPM 700) and temperature from a single probe tip built into the pen body itself, rather than a probe on a cable connected to a separate handheld display. That makes it a genuinely pocketable option for growers who want combo-style functionality without carrying a bulkier two-piece meter.
How it compares
It occupies a middle ground between Bluelab's single-parameter pens and the cabled Combo Meter.
- Versus the Bluelab Combo Meter, the One Pen trades the cabled probe-and-display design for a single streamlined unit, which some growers find easier to handle one-handed.
- Versus buying a separate pH Pen and EC Pen, the One Pen covers both parameters plus temperature from one device, at a price roughly between the two combined.
- Versus combo testers from Hanna Instruments or Milwaukee, Bluelab's reputation for durable, grow-room-specific build quality is the main reason growers pay a premium for the brand.
If you want all-in-one convenience in the most compact form Bluelab offers, this is the pick.
Usage guidance
As with any combined pH/EC pen, proper calibration is what keeps the readings trustworthy.
Calibration
Calibrate pH using 4.0 and 7.0 buffer solution, and conductivity using Bluelab's 2.77 EC standard solution, before first use and periodically afterwards.
Testing
Dip the sensor tip into your reservoir or run-off, let the reading settle, and take your pH, EC and temperature figures straight off the display.
Storage and care
Keep the sensor tip protected with its cap and a little storage solution between uses to stop it drying out, and rinse it after testing strong nutrient mixes.
Technical specifications
- Parameters measured: pH, conductivity (EC/CF/PPM 500/PPM 700), temperature
- Design: single all-in-one pen body with integrated sensor tip
- Calibration: 2-point pH (4.0/7.0), 1-point EC (2.77)
- Display: digital LCD
- Auto-off: yes
- Typical use: hydroponic reservoirs, coco and soil run-off testing
Who this is for
- Growers who want combo-meter convenience in a more compact, single-pen design
- Anyone who finds a cabled probe-and-display meter awkward to handle
- Hobby to mid-level growers testing pH and EC regularly who want one device rather than two
- Growers who value pocketable, grab-and-go testing over a larger benchtop-style unit
Best suited to growers who want all-in-one readings without the bulk of a cabled combo meter.
Our take
The One Pen gives you the same core convenience as the Combo Meter - one dip, every number you need - in a tidier, single-piece design. It's a genuine alternative rather than a downgrade, and worth considering if handling a cabled probe has ever annoyed you.
If compact, all-in-one testing appeals more than a cabled combo unit, this is a solid way to get there. Does exactly what it should, day in, day out.
