Aqua One AquaNano 30/40 Sponge Foam Filter Media 116s / 117s Aquarium Fish Tank
Aqua One AquaNano Sponge Foams. AquaNano 22 Sponge Foam - 116s. AquaNano 60 Sponge Foam - 117s. These 117s sponges for the aquariums should be replaced every 8 weeks to ensure peak tank conditions and crystal-clear water.