JBL AquaEx Gravel Cleaner NanoGravel cleaner for smaller Nano aquariums. Small but powerful gravel cleaner for the siphoning of waste in small aquariums. Use: hold the gravel cleaner into the water, briefly suck in down the hose once and the water flows into the bucket. Immerse gravel cleaner into the substrate and the suction removes waste from the bottom. The square cross section also enables you to siphon waste in the aquarium corners. Removable protective sieve to prevent