The Reef Octopus Regal 300-INT Protein Skimmer is the largest in-sump model in the Regal line, rated from 500 gallons at heavy bioload up to 740 gallons at light bioload. It runs the same 36V VarioS-6S variable-speed pump as the 250-INT in a taller hybrid conical body scaled for serious bioload. Bioload capacity: 500 gallons (heavy), 620 gallons (medium), 740 gallons (light), excluding sump Pump: VarioS-6S variable-speed pinwheel pump, 36V, 5 power settings Control features: float switch input, 15/60-minute feed-pause modes, 0-10V third-party controller input, integrated memory Recommended sump water height: 7.9-9.9 inches At up to 740 gallons rated, the 300-INT is the top of the Regal in-sump lineup — a common fit for large display tanks and multi-tank systems sharing a central sump.Compatible replacement parts: VarioS-6S pump kits sized for the Regal 300 series.
