Red Sea ReefMat 500 Replacement RollEfficient, high flow 50 g m2 filter roll made from non woven, polyester fleece. Replacement roll for the ReefMat 500 Auto Filter Roller. Although specific lifespan will vary according to system parameters such as volume, bio load, feeding schedule, and initial water quality; each 28m roll of filter fleece is expected to last 5 8 weeks on a moderately stocked 80 gallon reef system. Bare bottom tanks will typically exhaust rolls at a faster rate.