The Raritan Engineering PST12EX2 Complete Purasan EX Treatment System is a Type I Marine Sanitation Device (MSD) designed for comprehensive marine waste treatment in both saltwater and freshwater environments. Originally developed as an alternative to Lectra/San systems for Kentucky's freshwater lakes, this 12V system has gained widespread popularity among boaters who prefer treating waste at the source rather than relying on holding tank pump-out facilities.
How the Purasan EX Works:
The Purasan EX operates as a flow-through treatment system. When the toilet flushes, waste enters the treatment tank where a measured amount of disinfectant is automatically introduced to neutralize the waste. Simultaneously, an equal volume of treated waste is discharged overboard through the thru-hull fitting. A high-speed macerator inside the tank breaks down solid waste and ensures thorough contact between the disinfectant and waste material.
Key Features and Improvements:
- Tablet-based disinfection system using compounds similar to commercial wastewater treatment plants
- Built-in control panel that alerts users when tablets need replenishment
- Integrated air pump forces water into the treatment tank, preventing premature tablet deterioration
- Compatible with virtually any marine toilet on the market
- Flexible installation options with easier mounting than previous generations
- High-speed macerator ensures complete waste breakdown and treatment
- Operates on 12V DC power for standard marine electrical systems
Treatment Tablet System:
The system uses specialized treatment tablets that dissolve when flushed water passes over them, creating a sanitizing solution that drains into the treatment tank. Only freshwater is required for the tablet dissolution process, though toilets connected to the system can flush with either saltwater or freshwater.
Important Considerations:
While Type I MSDs allow treated discharge outside the three-mile limit in most areas, boaters should be aware of No Discharge Zones where any overboard discharge is prohibited. Vessel operators should evaluate their cruising patterns, local regulations, and pump-out facility availability when choosing between a treatment system and holding tank solution.
The complete system includes the treatment tank, macerator, air pump, control electronics, and all necessary components for a full installation. Replacement treatment tablets must be purchased separately for ongoing operation.
