Neptune Systems PM3 Dissolved Oxygen Module

Let’s 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 Dissolved Oxygen 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.

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.

Warranty & Support

This product carries a 1-year manufacturer warranty on hardware from the date of purchase. Probes are consumable items and carry a 90-day warranty.

Warranty support is handled by us directly. Message our WhatsApp support with your order number and we will diagnose the fault first. Most cases are solved by replacing a single part, so you rarely need to send the whole unit. If the item does need to come back, it ships to our Delhi warehouse, and courier cost in both directions is borne by the customer. Your GST invoice is valid proof of purchase for the claim.

Backorder & Dispatch Timeline

This item is stocked to order. Back-orders are consolidated and placed with our overseas suppliers once a month, on the last day of the month, and all such orders are shipped before the 15th of the following month.

Back-orders cannot be cancelled once they have been placed with the supplier. If you cancel before that, payment-gateway charges of 2% plus GST are deducted and the balance refunded. In the rare case a supplier cannot fulfil the item, we will offer you an alternative first, and refund in full with no deduction if you would rather not take it.

Setup & Use

The PM3 adds dissolved oxygen monitoring to an Apex and connects over AquaBus. The probe plugs into the module. A second port takes a temperature probe, and six switch inputs handle items like a top-off float or a leak alarm. The Apex can then alert you or start air pumps when oxygen drops.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 48 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.