Moving the Regal platform's reaction chamber outside the sump maximizes contact time at the high flow rates its largest sizes are built for. The Reef Octopus Regal Recirculating External line — 200EXT, 250EXT, and 300EXT — takes the Regal body external for the biggest tanks in the lineup.
Why External at the Top of the Range
At Regal's largest capacities, an external recirculating design gives water more time in the reaction chamber than a straight-through in-sump path, while also freeing up significant sump space that a body this size would otherwise occupy.
Choosing a Size
- Regal 200EXT — takes the 400-gallon-rated Regal 200 platform external, recirculating through the VarioS-4S pump.
- Regal 250EXT — takes the 300–635 gallon rated Regal 250 platform external.
- Regal 300EXT — the flagship of the Regal line, rated from 500 to 740 gallons and built external to maximize both capacity and contact time.
Setup Tips
- Plan cabinet or stand space for the external chamber before ordering — these are large units.
- Account for recirculation plumbing between the sump and external chamber in your build.
- Start the VarioS pump at a moderate speed and tune based on foam production over the first few days.
The Reef Octopus Regal Recirculating External line is available at Marine Concept Supply — order online or pick up at our shop in Wheeling, IL. Shop 200EXT, 250EXT, or 300EXT, and browse more protein skimmers.
