An investment in your own survival
There are many auto fill devices on the market today, however, most of them are mechanical floats similar to the toilet tank floats. Because they are mechanical devices, they are susceptible to malfunctions such as sticking, jamming, rusting, warping or corroding. as a result of this, most floats stick or malfunction in the closed position, resulting in an unchecked, continuous flow of water causing an overflow. If this happens in a koi pond, the result could be the chlorine or chloramine poisoning of the fish.
The AquaFill electronic water level controller is designed to fail in the open position, meaning that the 24-volt circuit to the solenoid is interrupted causing the solenoid that supplies the water to become non-operational. It is truly a "Fail-Safe" system, so consequently, the AquaFill is used by koi farms and breeders worldwide. The AquaFill's only competition is the auto fill, which uses probes to sense the water level through conductivity. It requires an elaborate, electronic circuit board to accomplish this. Because of the many electrical component parts, there are many things that can go wrong with it and does.
The AquaFill retails for $98 and the Levolor starts well over $300. As a result, pool contractors are switching to AquaFill, not just for the economics, but for its reliability and dependability in doing what it is designed to do. The AquaFill only has one moving part and that is a small styrene float bobber that rides up and down on a hermetically sealed shaft containing a micro leaf switch. This switch was designed to open and close thousands of times per day and carries a 5-year warranty against factory defects. The float acts as a switch between the 24-volt transformer and the inline solenoid switch. When the float bobber drops due to water loss through splashing and evaporation, two magnets embedded into the float cause the micro switch to close and completes the circuit, sending voltage to the solenoid and causing it to open and put water into the pond. The float is housed inside an enclosure, preventing water turbulence that would cause the bobber to bounce up and down causing the switch to oscillate on and off, and causing the solenoid to click on and off. This would create undue wear and tear on both the switch and the solenoid.