With my FX5 specially wrapped and filled with rock it has kept my Mabuna 240 reef tank with more than 60 Cichlids sparkling for more then 11 months without a cleaning. The photos below a testament to the performance and endurance of circumference filter design. Also below photos of the FX5 cleaned, re-wrapped with Poly-batten and and repacked with decomposed granite gravel. Decomposed granite polishes the water as good as carbon but without any adverse affects, available at any landscaping nursery for about $50 a ton delivered. At that price there is no need to clean it when dirty just returned to the garden and the plants love it, it will take me years to go through a ton LOL.