Bluelab Combo Meter with Leap pH Probe Review: pH, EC & Temperature in Any Substrate
The Combo Meter Gets an Upgrade
The Bluelab Combo Meter has been one of the most trusted 3-in-1 meters in hydroponics for over 25 years. It measures pH, EC, and temperature in a single portable device — everything a grower needs to manage nutrient solution chemistry on the go.
But the standard Combo Meter comes with a traditional glass-tip pH probe. That's perfect for liquid measurements, but it has a limitation: you can't push it directly into soil, coco coir, or rockwool without risking damage to the fragile glass membrane.
The Bluelab Combo Meter with Leap pH Probe (SKU: METCOMPLUS) solves this. It takes the proven Combo Meter platform and pairs it with the Bluelab Leap pH Probe — a reinforced spear-tip probe designed for direct insertion into any growing substrate. The result is a 3-in-1 meter that works everywhere: reservoirs, run-off, soil, coco, rockwool, and potting mix.
What's Different About the Leap pH Probe?
The Leap Probe is Bluelab's toughest pH probe. Its reinforced spear tip is designed to penetrate growing substrates without cracking or contaminating — giving you direct root zone pH readings that a standard glass-tip probe simply can't provide safely.
This matters because root zone pH and reservoir pH are not always the same. Substrates like coco coir and soil have their own buffering capacity. Even if your reservoir is at pH 6.0, the root zone pH may be different — and it's the root zone pH that actually determines nutrient availability to your plants.
The Leap Probe is also replaceable. When it reaches the end of its lifespan, you swap the probe, not the entire meter.
Key Features Explained
3-in-1 Measurement: pH, EC & Temperature
Like the standard Combo Meter, the METCOMPLUS measures all three fundamental parameters simultaneously:
- pH — via the Leap Probe, in solution or directly in substrate
- EC (Electrical Conductivity) — via the factory-calibrated conductivity probe, no further calibration required
- Temperature — in °C or °F, with Automatic Temperature Compensation (ATC) applied to pH and EC readings
Automatic Temperature Compensation (ATC)
Both pH and EC readings are affected by temperature. The METCOMPLUS automatically compensates for temperature variation, so your readings are accurate whether your nutrient solution is at 18°C or 26°C. This is especially important in environments where temperature fluctuates between day and night cycles.
Multiple EC Scales
The meter supports all four common conductivity scales — EC, CF, ppm 500 (TDS), and ppm 700 — so you can match your nutrient manufacturer's recommendations without conversion math. Switch between scales at any time.
2-Point pH Calibration with 30-Day Reminder
Two-point calibration at pH 4.0 and pH 7.0 gives you the most accurate pH readings. The built-in 30-day calibration reminder ensures you never miss a recalibration cycle — one of the most common causes of drifting pH readings.
2-Metre Cable for Hard-to-Reach Locations
The 2-metre (6.6 ft) probe cables give you the reach to measure in deep reservoirs, large growing beds, and hard-to-access locations without submerging the meter body.
KCl Storage Cap
The Leap Probe comes with a KCl (potassium chloride) storage cap to keep the probe tip hydrated between uses. Never store a pH probe dry — the KCl cap prevents membrane damage and extends probe life.
Bluelab Combo Meter vs. Combo Meter with Leap Probe: Which Should You Choose?
| Feature | Combo Meter (METCOM) | Combo Meter + Leap Probe (METCOMPLUS) |
|---|---|---|
| pH, EC, Temperature | Yes | Yes |
| Substrate insertion | No — standard glass-tip probe | Yes — reinforced spear-tip Leap Probe |
| Compatible media | Solution only | Solution, soil, coco, rockwool, potting mix |
| ATC | Yes | Yes |
| EC scales | EC, CF, ppm 500, ppm 700 | EC, CF, ppm 500, ppm 700 |
| Cable length | 2 m / 6.6 ft | 2 m / 6.6 ft |
| Price | $356.00 | $419.00 |
If you grow exclusively in hydroponic solution and never need to measure substrate pH, the standard Combo Meter is the right choice. If you grow in soil, coco, rockwool, or any other substrate — or if you want the flexibility to measure root zone pH directly — the Combo Meter with Leap Probe is worth the additional investment.
Which Growing Media Can You Measure?
- Nutrient solution — reservoir, run-off, and water supply
- Soil — direct insertion for root zone pH measurement
- Coco coir — substrate pH in coco-based systems
- Rockwool — slab and cube pH measurement
- Potting mix — container growing and transplant pH checks
Who Should Use the Bluelab Combo Meter with Leap Probe?
- Soil and coco growers who need pH, EC, and temperature plus direct substrate pH measurement
- Rockwool growers checking slab pH alongside nutrient solution EC and temperature
- Multi-media growers who work across different substrates and need one meter for all of them
- Commercial growers who need fast, accurate root zone data to optimise yield
- Anyone upgrading from the standard Combo Meter who wants multimedia capability
The Bottom Line
The Bluelab Combo Meter with Leap pH Probe is the most versatile 3-in-1 meter Bluelab makes. It delivers everything the standard Combo Meter offers — pH, EC, temperature, ATC, multiple EC scales, 2-point calibration, 2-metre cables — and adds the ability to measure pH directly in any growing substrate via the Leap Probe's reinforced spear tip.
If you're serious about root zone management and grow in anything other than pure hydroponic solution, this is the meter to have. At $419.00, it's a professional-grade instrument that pays for itself in better data and healthier plants.