Moving a skimmer's reaction chamber outside the sump maximizes contact time and frees up cabinet space, and the SRO Recirculating External line applies that approach across the largest SRO capacities. The SRO 5000ext, 6000ext, and XP8000E take their respective in-sump platforms and rebuild them as external, recirculating units.
Why Recirculating External Works at This Scale
At high flow rates, an external recirculating design gives water more contact time in the reaction chamber than a straight-through in-sump unit, while also moving a large skimmer body's footprint entirely out of the sump itself.
Choosing a Size
- SRO 5000ext — moves the SRO 5000 platform outside the sump, recirculating water through the Bubble Blaster HY-5000.
- SRO 6000ext — rated from 500 to 700 gallons, mounted external to the sump for maximum flexibility.
- SRO XP8000E — takes the XP8000 platform outside the sump for maximum contact time, recirculating through the largest standard Bubble Blaster pump.
Setup Tips
- Plan stand or cabinet space for the external chamber before ordering — these are large units that need a dedicated spot outside the sump.
- Account for recirculation plumbing in your build, since water needs a path up to the chamber and back to the sump.
- Break in gradually, expecting microbubble overflow during the first 1–2 weeks of operation.
The Reef Octopus SRO Recirculating External line is available at Marine Concept Supply — order online or pick up at our shop in Wheeling, IL. Shop SRO 5000ext, SRO 6000ext, or SRO XP8000E, and browse more protein skimmers.
