6 Pieces Plastic PP Float Switch Fish Tank Liquid Water Level Sensor,Model: DP5200

I used this float to monitor the activity of a sump pump (specifically looking for when the water level dropped which indicated the sump pump had run). After trying various other gadgets like a water level sensor (which failed in a matter of days), this float has been working flawlessly for weeks. It is used simply as a switch, with no load in the circuit. It is attached to an A-D converter that is connected to an Arduino Wifi that logs pump activity to a database on a web server. The float acts essentially as a resistor -- either very high resistance when the switch is open, and very low resistance when the switch is closed.I suspect that people who have had issues with this float have a load in the circuit that contains this switch, thereby drawing current through the float. Instead, use the float to send a signal to, say, an Arduino which then controls a relay that switches power to the load. This will keep the current through the float at a very low level. No need for an expensive Arduino -- a basic Nano will do.

These are great, very affordable and work fine.Let me just say in case anyone is an idiot like me. When the float is down (meaning away from the wires), the switch is ON. When it moves closer to the wires, the switch is OFF.There are two basic ways to use these. If you want to use them as an auto top off, the wires should be facing up so that as the water lowers, the switch can turn on a pump. If you want to use them to turn off a water source with a solenoid, such as when you're filling your RODI reservoir, flip it over so that the switch floats up to activate the solenoid when the water is high enough.

The glue that is used does not bond to the plastic nor the wires very well. In the picture you can see the slight crack between the glue and the housing. If the whole thing is put underwater, it will fail eventually due to water seeping in.

I liked that it gave me an option to Screw down the switch onto something to hold it in place, and one thing I didn’t like is that when I bumped the switch, sometimes it did not activate. However I don’t see that being an issue in normal use.

I used these levels switches to control a landscape watering system where water was pumped from a pond to a holding tank, then pumped to sprinklers with a second pump. the switches were used to monitor pond and holding tank levels to insure pumps would not be run dry. Several of the sensor proved to be unreliable - stuck in one state regardless of float position. I don't know what the cause is. I tend to suspect temperature because the failures happened to happen on warm days in the sun (but not direct sun).

these are so much better than the Stainless steel version. they seem to last a little longer and the wires are much longer and easier to work with.

Used it to fix my brio water dispenser, had issues with it not detecting the tank being full, upon replacement with this sensor works perfectly again!

Float switches typically have built in hysteresis, i.e., they turn on and off at different levels, to prevent pumps from rapidly turning on and off which can damage motors and relays. Fortunately, one can get hysteresis by connecting two float switches, at different levels, in series with the coil of a relay and have the relay shunt one of the float switches. For example, with a sump pump, the higher level float switch should be shunted by a relay. For the inconvenience of this extra circuitry and no directions from the manufacturer on how to do it, I gave one star for "Easy to Install."