Bluelab Pulse multimedia ec / moisture / temperature

Reads conductivity, moisture content and temperature directly in the medium, in under ten seconds. Every measurement goes wirelessly to the app on your phone.

The Bluelab Pulse pushes its 200 millimetre probes into soil, coco or potting mix and you press the button. Three values at once, with no samples and no pour-throughs. A built-in depth gauge makes sure you measure at the same depth every time, which is what makes readings comparable with each other.

Root-zone EC versus reservoir EC

This is the distinction the meter exists for, and it explains why growers who appear to do everything right still run into trouble.

What you measure in your reservoir is what you are about to give. That is a check on your own mixing, and it is useful. But the plant is not in your reservoir. It is in a pot, and something else happens there.

A plant takes up water faster than salt. What stays behind in the medium therefore gets slightly more concentrated with every watering. Water with too little runoff and that accumulates: you dutifully give 1.8 EC and after three weeks the pot sits at 3.2. The plant is then in a solution you never mixed, and the first symptoms (slow growth, burnt leaf edges) look like almost anything other than what they are.

The classic way to check is collecting runoff or making a slurry. That works, but it costs time, it disturbs the pot, and you measure a mixture rather than the place the roots actually are.

The Pulse measures in the substrate itself. You see build-up before the plant shows it, and you also see whether it is even: a pot near the door often reads differently from one in the middle of the tent.

Measuring moisture, and what to do with it

Moisture content is the second reading, and it drives your watering. Too wet means too little oxygen at the roots and an open door to root rot; too dry means stress and stalled growth. Both show above ground only days later.

In the app you can set a target range per medium. Measure outside it and the Blink function flags it on the meter itself. You do not have to take your phone out to know whether you are on track.

The app

Measurements travel over Bluetooth to the Pulse app and are stored there with date and time. You can review trends, compare readings, attach notes to a measurement and export the data. The app is free for iOS and Android, and available in Dutch among other languages.

Technical Specifications:

• Measures: conductivity, moisture content and temperature
• EC range: 0 to 15 EC
• accuracy: ± 0.1 EC
• Temperature accuracy: ± 1 °C
• Probe length: 200 mm
• probe separation: 50 mm
• active tip: 50 mm
• Minimum pot size: 2 litres
• Media: soil, potting mix, coco blends and nutrient solution
• Calibration: optional, single step; custom per-medium calibration available in the app
• App: free, for iOS and Android over Bluetooth, available in Dutch among others
• Measuring time: three values in under 10 seconds

Frequently asked questions

Do I need a phone to use it?
Not for a single reading: the Blink function shows on the meter itself whether you are inside your set range. For storing, comparing and exporting measurements you use the app.

Does it work in rockwool?
It is built for soil, potting mix and coco blends. In rockwool blocks the 200 millimetre probe length is usually the obstacle rather than the measurement itself.

Why a minimum pot size of 2 litres?
Because the probes need a certain volume of medium around them. In a smaller pot you read too much edge and too little root zone.

Does this replace my conductivity pen?
No, they measure in two different places. The pen reads what you are about to give, the Pulse reads what is actually in the pot. Together they give you the whole picture.

Does it measure pH as well?
No, conductivity, moisture and temperature only. For pH in a medium, the Bluelab Multimedia pH Meter with a Leap probe or the Soil pH Pen is the tool.