Height of Baffles for a Refugium Sump

Protein skimmers and splashing water cause microbubbles in the sump. Baffles slow the water flow and prevent bubbles from traveling into the display tank. Place four baffles in your aquarium; place one between the sump and refugium and three between the refugium and the return.

  1. How Bubble Traps Work

    • Three-baffle bubble traps allow microbubbles to leave the water, keeping them out of the return area. Alternating bottom-open with top-open baffles forces the water over and under them to reach the return area from the refugium. The lighter air rises to the top and leaves the water during the trip.

    Placement of Baffles

    • Attach the baffle closest to the refugium to the bottom to retain the sand substrate. A short last baffle of the bubble trap prevents the return from running dry. The middle baffle, raised off the bottom, runs most the height of the tank. Prevent overflow during power outages by keeping sumps/refugiums only half full.

    Baffle Height

    • The protein skimmer's requirements determine the height of the sump-refugium baffle; normally a 9-inch baffle works well. Make the first baffle of the refugium-return bubble trap half the height of the aquarium. Subtract 2 inches from the aquarium height for the middle baffle; set it 1 inch from the bottom. Make the baffle nearest the return 6 inches high.