Description
Neptune Systems Lab Grade Dissolved Oxygen Probe
Accurate, Long-Term Dissolved Oxygen Monitoring
This lab-grade dissolved oxygen (DO) probe is designed for use with the Neptune PM3 module, providing precise and reliable measurement of oxygen levels in your aquarium. Unlike traditional probes, the replaceable membrane design allows for long-term use without needing full probe replacement.
Key Features
- Lab-grade dissolved oxygen measurement
- Compatible with Neptune PM3 module
- Replaceable sensing membrane for extended lifespan
- Includes 3 m cable
- Cost-effective long-term maintenance
Replaceable Membrane System
The probe’s sensing membrane can be replaced approximately every 3 months, restoring performance to like-new condition. Replacement is quick, simple, and economical, making this probe a long-term solution for oxygen monitoring.
Why Monitor Dissolved Oxygen?
Dissolved oxygen is a critical parameter in both reef and freshwater aquariums. Oxygen levels are influenced by surface agitation, gas exchange, biological load, and organic waste breakdown.
- Low oxygen levels can stress or kill fish and corals
- Overstocked systems are especially at risk
- Decomposition of organic matter consumes oxygen
- Gas exchange at the surface is the primary oxygen source
Oxygen levels can be improved through increased surface agitation, air stones, or optimized water flow.
Recommended Dissolved Oxygen Levels
- Optimal range: 4.5 – 7 ppm
- Stress may occur below: 4 ppm
- Dangerous levels: below 3 ppm
Dissolved Oxygen Reference Table (ppm at 100% Saturation)
| Temp °C (°F) | 0 ppt | 5 ppt | 10 ppt | 15 ppt | 20 ppt | 25 ppt | 30 ppt | 35 ppt |
|---|---|---|---|---|---|---|---|---|
| 18 (64.4) | 9.45 | 9.17 | 8.90 | 8.64 | 8.38 | 8.14 | 7.90 | 7.66 |
| 20 (68.0) | 9.08 | 8.81 | 8.56 | 8.31 | 8.06 | 7.83 | 7.60 | 7.38 |
| 22 (71.6) | 8.73 | 8.48 | 8.23 | 8.00 | 7.77 | 7.54 | 7.33 | 7.12 |
| 24 (75.2) | 8.40 | 8.16 | 7.93 | 7.71 | 7.49 | 7.28 | 7.07 | 6.87 |
| 26 (78.8) | 8.09 | 7.87 | 7.65 | 7.44 | 7.23 | 7.03 | 6.83 | 6.64 |
| 28 (82.4) | 7.81 | 7.59 | 7.38 | 7.18 | 6.98 | 6.79 | 6.61 | 6.42 |
| 30 (86.0) | 7.54 | 7.33 | 7.14 | 6.94 | 6.75 | 6.57 | 6.39 | 6.22 |
For example, at 26°C (78.8°F) and 35 ppt salinity, the maximum dissolved oxygen level is approximately 6.64 ppm at full saturation. In practice, most aquariums operate around 70% saturation, making proper monitoring essential.
