Water lifting device for lifting purified water from a purification tank comprising: a U-shaped pipe, whose base is immersed in a liquid for purification in a purification tank with a first leg as the lifting pipe and a second leg as the ventilation pipe, with the base being contrived as a connecting manifold between the lifting pipe and the ventilation pipe, and with upper ends (11, 12) of the legs (6, 8) projecting out of the liquid for purification; an intake fitting disposed on the ventilation pipe at a lower water level in relation to the purified water to be lifted and at least one compressed air connection disposed on the lifting pipe and below the water level of the intake fitting; with the intake fitting being contrived as an inverted siphon device, and with the inverted siphon device having an inverted U or V-shaped manifold (18, 19) which feeds into a dip pipe fitting with an intake port, characterised in that the dip pipe fitting has a compressed air connection to a second compressed air line, and in that the water lifting device has a control device for controlling the operation of the water lifting device, with the control device being set up to control ventilation of the inverted siphon device via the second compressed air line in such a way that, temporally for all operating phases except the lifting phase, an air bubble occupies the inverted siphon bend section and prevents the hydraulic connection between the purification tank and the lifting pipe, and with the control device being set up so that during the lifting phase, it switches compressed air valve (16, 31), of which there is at least one, in the lifting pipe from a closed position to an open position to transport water via the intake fitting in ventilation pipe to an open upper end of the lifting pipe and with the control device being set up so that after water withdrawal in the lifting phase, the dip pipe fitting with the compressed air connection is activated as an air-lift pump and before feeding the purification tank with liquid for purification, the water lifting device is filled up with purified water. a U-shaped pipe, whose base is immersed in a liquid for purification in a purification tank with a first leg as the lifting pipe and a second leg as the ventilation pipe, with the base being contrived as a connecting manifold between the lifting pipe and the ventilation pipe, and with upper ends (11, 12) of the legs (6, 8) projecting out of the liquid for purification; an intake fitting disposed on the ventilation pipe at a lower water level in relation to the purified water to be lifted and at least one compressed air connection disposed on the lifting pipe and below the water level of the intake fitting; with the intake fitting being contrived as an inverted siphon device, and with the inverted siphon device having an inverted U or V-shaped manifold (18, 19) which feeds into a dip pipe fitting with an intake port, characterised in that the dip pipe fitting has a compressed air connection to a second compressed air line, and in that the water lifting device has a control device for controlling the operation of the water lifting device, with the control device being set up to control ventilation of the inverted siphon device via the second compressed air line in such a way that, temporally for all operating phases except the lifting phase, an air bubble occupies the inverted siphon bend section and prevents the hydraulic connection between the purification tank and the lifting pipe, and with the control device being set up so that during the lifting phase, it switches compressed air valve (16, 31), of which there is at least one, in the lifting pipe from a closed position to an open position to transport water via the intake fitting in ventilation pipe to an open upper end of the lifting pipe and with the control device being set up so that after water withdrawal in the lifting phase, the dip pipe fitting with the compressed air connection is activated as an air-lift pump and before feeding the purification tank with liquid for purification, the water lifting device is filled up with purified water.