In order for the water to get out what in the river just comes first connect the hose to the water supply, as long run be run until the water in the basin, then hang the hose end in the shower. Have the pipe cut off something, so the device depends to about 1/3 deep into the basin and the water can run completely unattended. If small fish in the tank are, attach a Perlonstrumpf best around the screen, so the little ones do not end up in the drain.
