Neptune Systems PM3 Dissolved Oxygen Module
Lets say your Apex system detects low dissolved oxygen in your aquarium, you could have pumps on standby waiting to be activated when levels hit below optimal as well as send you an email or text message
Add the Dissolved Oxygen Module: PM3 to your Apex Neptune System to allow continuous real time monitoring of your reef tanks dissolved oxygen levels.
- Real-time monitoring of dissolved oxygen in reef aquarium
- Module has extra Temp Probe port (sold separately)
- I/O Switch Inputs for ATO, feed buttons, leak alarms, etc.
Recommended DO level for reef tanks is between 4.5ppm - 7ppm
With so many additives that are hitting the market today, that focus on biological nutrient removal can easily and rapidly take up the dissolved oxygen in the tank leaving it very hard or nearly impossible for your fish and corals to breathe. If you employ any bacterial nutrient control system like biopellets, carbon dosing, or nitrate reactors it is a wise investment to purchase the PM3 and dissolved oxygen probe.
Dissolved oxygen is one of the most critical components to a healthy, thriving tank, but is commonly looked over due to the probes high price tag. Once the probe is purchased it can last a lifetime with the straightforward and easily replaceable membrane that is usually less than 10 dollars to replace. When it comes to probes, you get what you pay for, and Neptune has sourced one of the best lab grade dissolved oxygen probes available today.
The PM3 module also has a bonus that it comes with an open port for a temperature probe and also another opening for an I/O switch port that would be used with the breakout box for monitoring float switches, magnet switches, and much, much more.
Features
- Monitor/Control Dissolved oxygen and temperature
- 6 digital inputs for float switches, water on floor sensors, pressure sensors, etc
- Plug and Play. Automatically recognized when installed into the system
- Two AquaBus connectors for flexible expansion via AquaBus
- Comes with 3′ AquaBus cable
- Galvanic Isolation for accurate and reliable probe readings
- LED Status Indicator
- Upgradeable firmware
- Compatible with all Apex systems
Dissolved oxygen can easily be manipulated with either air pumps and air stones, aiming return nozzles at the surface of the water, or a water pump that vertically pushes the water to the surface to allow for gas exchange. In a typical reef tank, most O2 is lost and transferred with CO2 at the surface of the water. Another large sink for dissolved oxygen to be consumed is settled detritus, food, and other dissolved organic compounds. As the process breaks down organic compounds dissolved oxygen will be consumed. For overstocked tanks that can cause a huge issue as your animals will consume the oxygen as well as their waste which could lead to dangerously low levels of dissolved oxygen.
Dissolved Oxygen Saturation Table
| C (F) | 0ppt | 5ppt | 10ppt | 15ppt | 20ppt | 25ppt | 30ppt | 35ppt |
| 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 |
As an example a tank with a salinity of 35ppt and a temperature of 78.8 degrees Fahrenheit can have a maximum dissolved oxygen amount of 6.64ppm. A freshwater tank with a salinity of 5ppt at 75.2 degrees can dissolve 8.16ppm of oxygen at 100% saturation. On average dissolved oxygen (DO) rates will be around 70%. We suggest maintaining a DO level between 4.5-7ppm, as stress signs can be seen anywhere below 4ppm and fatalities can start to happen below 3ppm.
Note: Dissolved Oxygen probe sold separately.
Apex controller required and sold separately.
