The invention relates to liquid level sensors, namely the sensors for determining the level of the liquid level in the aquarium and terrarium.The technical result of the utility model is to improve the design of the water level sensor holder, as well as the extension of its use, which is achieved due to the fact that the claimed water level sensor aquarium comprising a housing, the reed switch and the float on which is placed a magnet, characterized in that the housing is divided into two blocks - signal and measuring, in the central part of the measurement block has a recess on the bottom face of the recess two openings formed, the float is situated in a recess, the shape of the float with The appropriate shape of the recess, the width and the float length correspond to the width and length of the recess and the height of the float is less than the height of the recess, the bottom part of the measurement block is a magnet, while in the signal block is located back to said magnet reed switch, the blocks are bonded together by magnets, which are arranged on two in the same field block opposite polarities to each other, in the upper part of the signaling unit is mounted back on the float magnet reed switch.
