An in-water suction cleaner includes a portable housing for disposing at water of a pool or tank, a motorized unit supported in the portable housing for vacuuming a suction cavity of the portable housing to suck the water in the suction cavity out of the portable housing through a fluid outlet of the portable housing so as to create a suction at a fluid inlet of the portable housing, a manual scrubbing arrangement detachably coupled at the fluid inlet of the portable housing for scrubbing pool or tank surfaces and for sucking the water into the suction cavity at the same time, and a filtering element replaceably disposed in the suction cavity for filtering the water from the fluid inlet to the fluid outlet through the suction cavity so as to ensure the water after filtered being discharged back to the pool or tank via the fluid outlet.