JBL Proclean Aqua Ex 10-35Substrate (gravel) cleaner for cleaning aquariums with 10 35 cm in height Small, but smart and very effective gravel cleaner to siphon off waste from small aquariums Use: Hold the gravel cleaner under the water, briefly suck down the hose once and let the water flow into the bucket. Immerse the gravel cleaner into the substrate and the suction will remove the waste from the bottom The square cross section also enables you to siphon off waste from the