Using Auto top off system for my tank without reservoir!
I have been used this Auto Top Off for couple years until now that I bought from
www.autotopoff.com
I use two Solenoid Valves to control two float valves (for safety if one fail another one backs up).
The solenoid is an electronic valve capable of handling the higher pressure of reverse osmosis (RO) or city water system. The valve opens when powered, and remains closed when not energized.
Two Float Valves.
The controller powers a device when the lower float switch senses that your tank water level is low. The device will be turned off when the lower float switch senses your water level is high. The top switch is a backup in case the bottom switch fails.
Water will release to my sump when the lower switch senses water level is low.