I have a reservior of water which feeds a vertical garden.
I want to install a type of switch/valve?? that fills the reservoir to a specific height if the water drops below a certain point (low water mark). The reasoning is if the reservoir runs dry the water pumps cooks out.
A float switch (like those used in a toilet) will not work (to my knowledge) as the water level drops and rises during the day (when the water pump comes on) but only reaches the low water mark every few weeks after some evaporation takes place. A float switch would fill the reservoir every time the water level drops, creating over flow.