Bluelab PPM Pen | Waterproof Conductivity Pen for EC and ppm

What the Bluelab PPM Pen Reads, and How Close

Nutrient charts do not agree on units, which is why this pen lets you pick. It covers ppm 500 from 0 to 5000, ppm 700 from 0 to 7000 and EC from 0.0 to 10.0. Accuracy runs ±50 ppm on the 500 scale, ±70 on the 700 and ±0.1 EC, measured at 25°C. Temperature comes along as well, 0 to 50°C or 32 to 122°F, to within a degree. Automatic temperature compensation does quiet work behind all of it. On an uncompensated meter a cold reservoir reads low and a warm one reads high. That gap is wide enough to move a feeding decision. This one arrives factory calibrated, so the first reading is a reading rather than a setup job.

Living With a Conductivity Pen Day to Day

The care routine is short. Rinse it under running water after every use so nutrient salts do not build up on the electrodes. Clean the probe properly about every two weeks. That is the whole of it, and skipping it is the usual reason a pen starts reading oddly. Calibration is optional on a conductivity meter, which is not true of a pH one. A bottle of 2.77 EC standard is a check here, not a chore. The body is fully waterproof and it floats, which matters more than it sounds when you are leaning over a full tank. A backlit screen, a hold function, auto off and a low battery warning cover the rest, on one AAA cell. The probe is not replaceable. When the electrodes eventually go, the pen goes with them. Anyone who would rather change a probe than a meter should look at the OnePen.

Key Features

• Selectable units: ppm 500, ppm 700 or EC, so it matches whichever scale your nutrient chart uses.
• Reads to ±50 ppm: On the 500 scale, or ±70 on the 700 scale and ±0.1 EC at 25 degrees.
• Automatic temperature compensation: A cold tank reads low on an uncompensated meter. This one corrects for it.
• Temperature as well: 0 to 50 degrees Celsius, or 32 to 122 Fahrenheit, to within a degree.
• Factory calibrated: Ready on arrival, and calibration stays optional rather than routine.
• Waterproof and it floats: Useful the first time it goes into a full reservoir by accident.
• Two week cleaning cycle: Rinse after each use, clean the probe properly every couple of weeks.
• Backlit with hold and auto off: Plus a low battery warning, all running from a single AAA cell.
• Probe is not replaceable: When the electrodes fail the pen is finished. The OnePen takes a new probe.
• One year warranty: Repair or replacement, from Bluelab.

Technical Specifications