Compact Series
Compact MS (CMS)
Perfect for spot checking. 17" × 1.75". Up to 7 parameters: Temp, SpConductivity, pH, DO, ORP, TDG. RS-232, SDI-12, RS-485. 120,000-measurement memory. 200 m depth.
Full specifications →Multiprobes
HydroTech compact multiprobe sondes
Compact Series
Compact DS (CDS)
For spot checking and unattended deployments. 21.5" × 2.6". Up to 10 parameters including self-cleaning turbidity, depth, TDG. Internal 8×AA battery. 225 m depth.
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Specialty Sonde
TDG-3
Monitors Temperature, Depth (25 m), and Total Dissolved Gas (TDG). Integrated RS-232, MODBUS, and SDI-12. Designed for TDG monitoring with SDI-12 dataloggers. 2-year warranty.
Full specifications →In-Situ® Sondes
Aqua TROLL® Multiparameter Sondes
Five in-situ Aqua TROLL platforms cover everything from quick spot checks to unattended, multi-month deployments. The 500/600/700/800 share one ecosystem of smart, interchangeable sensors, VuSitu mobile app, and cable/telemetry accessories — pick the port count and power option that fits the job.
Legacy · Spot Check
Aqua TROLL 400
Economical, fixed-sensor probe for temperature, conductivity, DO, pH/ORP, and pressure. No internal battery or memory — runs off external power through a datalogger or handheld display.
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Current · Spot Check
Aqua TROLL 500
Five-port sonde with up to 4 smart, interchangeable sensors and a motorized wiper. The direct replacement for the 400, and a solid pick for low-flow groundwater sampling.
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Current · Long Deployment
Aqua TROLL 600
Adds an internal battery, onboard memory, and autonomous logging to the 500 platform for unattended, long-term groundwater monitoring — 9+ months on 2 D-cell batteries.
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Current · Spot Check
Aqua TROLL 700
Seven-port sonde with up to 6 smart sensors for surface-water work needing more parameters — algae pigments, nutrient ISEs, and dye tracers — plus onboard logging via external/telemetry power.
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Current · Long Deployment
Aqua TROLL 800
The flagship of the family: 7 ports, 6 smart sensors, internal battery, and autonomous logging for long-term coastal, estuary, and HAB monitoring.
Full specifications →Compare
Aqua TROLL Family Comparison
| Feature | Aqua TROLL 400 | Aqua TROLL 500 | Aqua TROLL 600 | Aqua TROLL 700 | Aqua TROLL 800 |
|---|---|---|---|---|---|
| Release generation | Legacy | Current | Current | Current | Current |
| Primary use | Spot check & short deployment | Spot check | Long deployment | Spot check | Long deployment |
| Internal battery | No | No | Yes | No | Yes |
| Internal memory | No | No | Yes | Yes | Yes |
| Autonomous logging | No | No | Yes | Yes | Yes |
| External power | Required | Required | Optional | Required | Optional |
| Sensor technology | Fixed sensors | Smart interchangeable | Smart interchangeable | Smart interchangeable | Smart interchangeable |
| Maximum smart sensors | Fixed only | 4 | 4 | 6 | 6 |
| Wiper | No | Yes | Yes | Yes | Yes |
| Vented version | No | Optional | Yes | Optional | Yes |
| Pressure rating | 150 psi | 150 psi | 350 psi | 350 psi | 350 psi |
| Bluetooth (VuSitu) | Limited | Yes | Yes | Yes | Yes |
| LCD status display | No | Yes | Yes | Yes | Yes |
| SDI-12 | Yes | Yes | Yes | Yes | Yes |
| Modbus RS-485 | Yes | Yes | Yes | Yes | Yes |
Bluetooth/VuSitu pairing on any Aqua TROLL sonde — including with our Rugged Android Device — requires a TROLL Com Plus or Wireless TROLL Com (sold separately). The 400's Bluetooth is limited and uses a separate TROLL Com adapter.
Sensor Comparison
| Sensor | 400 | 500 | 600 | 700 | 800 |
|---|---|---|---|---|---|
| Temperature | ✓ | ✓ | ✓ | ✓ | ✓ |
| Conductivity | ✓ | ✓ | ✓ | ✓ | ✓ |
| Pressure / Level | ✓ | Optional | Optional | Optional | Optional |
| Dissolved oxygen | ✓ | ✓ | ✓ | ✓ | ✓ |
| pH / ORP | ✓ | ✓ | ✓ | ✓ | ✓ |
| Turbidity | — | ✓ | ✓ | ✓ | ✓ |
| Chlorophyll-a | — | ✓ | ✓ | ✓ | ✓ |
| Blue-green algae (PC) | — | ✓ | ✓ | ✓ | ✓ |
| Blue-green algae (PE) | — | ✓ | ✓ | ✓ | ✓ |
| FDOM | — | ✓ | ✓ | ✓ | ✓ |
| Crude oil | — | ✓ | ✓ | ✓ | ✓ |
| Rhodamine WT | — | ✓ | ✓ | ✓ | ✓ |
| Fluorescein WT | — | ✓ | ✓ | ✓ | ✓ |
| Nitrate ISE | — | ✓ | ✓ | ✓ | ✓ |
| Ammonium ISE | — | ✓ | ✓ | ✓ | ✓ |
| Chloride ISE | — | ✓ | ✓ | ✓ | ✓ |
What Changed from the 400?
| Aqua TROLL 400 | Aqua TROLL 500 / 600 / 700 / 800 |
|---|---|
| Fixed sensor package | User-selectable smart sensors |
| No antifouling wiper | Automatic motorized wiper |
| Limited parameter selection | Over 15 available sensor types |
| No onboard display | LCD showing battery, sensors, and health |
| Older communications | Bluetooth + SDI-12 + Modbus + telemetry |
| No field-expandable capability | Sensors can be added or replaced in minutes |
| Best for routine groundwater checks | Suitable for groundwater, surface water, coastal, wastewater, aquaculture, HAB monitoring, and research |
Which Model Fits Which Application?
| Application | Best choice |
|---|---|
| Replace an existing Aqua TROLL 400 | Aqua TROLL 500 |
| Long-term groundwater deployment | Aqua TROLL 600 |
| Surface water with many parameters | Aqua TROLL 700 |
| Long-term coastal or estuary monitoring | Aqua TROLL 800 |
| Harmful algal bloom (HAB) monitoring | Aqua TROLL 700 or 800 |
| Low-flow groundwater sampling | Aqua TROLL 500 or 600 |
Accessories
Aqua TROLL Cables & Accessories
Every Aqua TROLL sonde ships bare — you'll also need a RuggedCable to power it and carry data to a logger, controller, or TROLL Com. Choose vented or non-vented to match your instrument's pressure sensor.
Cables
Non-Vented RuggedCable
Titanium Twist-Lock cable for non-vented (absolute pressure) Aqua TROLL and Level TROLL instruments. IP68, Kevlar reinforced, custom lengths up to 4,000 ft. Carries Modbus, SDI-12, or 4-20mA.
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