This cleaning tool pairs an exterior magnetic handle with an interior scrubbing pad, letting the pad be guided across the inside of an aquarium wall while the handle stays dry on the outside. Each unit includes one pad suited to glass surfaces and one suited to acrylic surfaces, so a single tool can serve either tank material. The interior scrubber is weighted at the bottom so that if it separates from the outer magnet, it sinks straight down rather than floating out of reach. A bowed-bottom shape keeps the pad riding above the substrate, which helps avoid trapping gravel or sand that could mar the tank wall. No tools or assembly are needed; the magnet is simply placed against the outside of the tank opposite the submerged scrubber. Replacement pads for the scrubbing surface are sold separately once the original pads wear down.