Every week, the bottom of your tank should be vacuumed to remove waste products or uneaten food left by your fish. The more that is removed the cleaner the water will be and the safer its quality.
This siphon gravel cleaner allows you to not only clean the gravel, as the gravel gets sucked into the end chamber as the water is siphoned out, it also agitates the gravel releasing any debris stuck in between. This means more debris is removed than just siphoning out the water itself.