The pad is a compact, durable scrubber sized for use directly in hand rather than mounted on a pole or magnet, giving the user close control over pressure and placement while cleaning. Each version is built for one tank surface material only, since a pad meant for glass can be too abrasive for acrylic and vice versa. The pad measures roughly three inches square and is intended to be worked directly against the interior tank wall to lift algae film from flat surfaces and tight corners. It should be rinsed with tap water before and after each use and is not intended for use on dry surfaces. If the pad picks up aquarium gravel while cleaning, it should be rinsed clean before continuing, since trapped gravel can scratch the tank. Each package contains one scrubbing pad and no assembly or setup is required before use.