Unusable because too weak from the power and only for basins under 40. height. So a sucker to be good if you even want to suck sludge having to perform without a water change so, just who is a pool with a water level of more than 40 cm has the need to do a water change, as the cup only to a mark of about 35 cm may be immersed. For small basins to about 112l and who just wants to suck the sludge ok but the gravel itself fine can not be cleaned, but the suction power is too weak.
