Treeger Par Meter (w/ DLI measurement)

What does the Treeger PAR Meter actually measure?

The Treeger PAR Meter measures PPFD (µmol/m²/s) and DLI (mol/m²/day), giving you real-time and daily totals of plant-usable light in the 400–700nm PAR range. It doesn’t measure UV or far-red light, which are outside the standard PAR spectrum.

How accurate is the Treeger PAR Meter?

It offers repeatability around ±1 µmol/m²/s and displays PPFD in 0.1 or 1 µmol increments depending on intensity. It’s far more accurate than lux meters and avoids spectrum-based guesswork from phone apps.

Can I use the Treeger PAR Meter with LED lights, sunlight, or in greenhouses?

Yes—Treeger is compatible with all horticultural lighting, including LED, HID, and natural sunlight. It’s also great for checking light levels in greenhouses, propagation racks, and indoor shelf setups.

How do I use the Treeger PAR Meter to map my grow space?

Measure PPFD at canopy height using a 3×3 or 4×4 grid pattern across your grow area. Use the Min, Max, and Avg features to check light uniformity, spot hotspots, and optimize fixture placement or dimming.

Does the Treeger PAR Meter calculate DLI automatically?

Yes—DLI is calculated based on your PPFD readings and light schedule. Use it to monitor daily totals and avoid over-lighting, which can cause stress or wasted energy.

What PPFD levels should I aim for with seedlings, veg, and flower?

Seedlings prefer lower PPFD, veg stages do best with moderate levels, and flowering typically benefits from higher intensity. The Treeger helps you fine-tune light output based on plant stage and environmental conditions.

Can the Treeger PAR Meter help prevent plant stress and stretching?

Yes—it lets you spot when PPFD is too low (causing stretching) or too high (leading to light stress or bleaching). It also reveals when symptoms are due to light overload rather than true deficiencies.

What accessories are included with the Treeger PAR Meter?

It includes a remote sensor, a 1.5m coiled cord, a 3.5m straight cord, and is often sold with an optional extendable stick. Many versions are compatible with tripod mounting for hands-free mapping.

Is the Treeger PAR Meter easy to use?

Yes—it’s compact, lightweight, and simple to operate. The remote sensor helps in tight spaces, and the interface includes stored readings, Max/Min/Avg modes, and optional backlighting for dark tents.

What batteries does the Treeger PAR Meter use?

It runs on 2 × AAA batteries. Battery life varies based on usage, but it’s optimized for multiple grow sessions. Store it dry when not in use to prolong its life in humid environments.

Does the Treeger PAR Meter store readings or averages?

Yes—it stores up to 99 readings and offers Max, Min, and Avg modes. This is helpful for tracking lighting changes over time or comparing different zones in your grow area.

How do I take an accurate reading with the Treeger PAR Meter?

Hold the sensor flat at canopy height, avoid casting shadows, and let the reading settle before recording. Keep the sensor level and use consistent angles for reliable comparisons.

Do reflective tent walls affect readings?

Yes—reflective walls bounce light back and can increase edge PPFD. That’s normal and beneficial. However, Treeger still helps you adjust for hotspots or under-lit corners by optimizing height and layout.

Does the Treeger PAR Meter need calibration or maintenance?

It’s factory-calibrated for typical grow use. Just keep the sensor clean using a dry or slightly damp microfiber cloth—avoid harsh chemicals or soaking. Dirty sensors cause inaccurate readings.

What’s the most common mistake when using a PAR meter?

Only measuring the center. Light uniformity matters—use a grid to map your whole canopy and avoid over- or under-lighting critical zones. Treeger makes that process fast and accurate.