Device_class Tank

We do not have connection to a municipal water line so we installed a couple of tanks up on a hill with a float in it. I am reading out the state of the float with a AC/DC octo and an ESP01 but there is no device class for it. Wet/dry is confusing our older inhabitants so I’d love it if a device class called “tank” or “float” with the states “full” and “not full” could be implemented. I am struggling to come up with a beter state description then “not full” but having the 0 state be “empty” would not be accurate as the float only operates in the top of the tank.

Thanks for your consideration!