6 Pieces Black Water Level Sensor Aquarium Tank Side Mounted Horizontal Liquid Float Switch

Works great with Arduino to control nutrient solution levels in hydroponic system. digitalRead(A0); returns "1" or "0." For my application, as sensor falls, a "1" is sent to the Arduino, which charges a DC-DC relay to activate normally closed solenoid valve until signal reads "0" again. I was hesitant to order after reading a lot of the reviews that insisted they go out after a short while, until I more closely examined the reviews. You cannot wire these directly between a source and a load (over about 5v) or they will predictably burn out! They are sensors, not switches, and as such must be "read" by another device that is then able to act upon it. As at least one other reviewer has noted, Arduino is a simple and safe platform for reading the signal and causing some other action based on the state of the sensor. If you need more info, Youtube it - "Arduino float switch"

Very simple reed switch. So far, all of them work great. The supply an input to a microcontroller. These are very low current switch, keepnthat in mind. If you are looking to directly use it as an inline switch, I would suggest using it to feed a MOSFET or opto-isolator. I would recommend using a SCR if it is for AC current

Used these on my 300 gallon rain (barrel) collection system. Working great! Programmed a WeMos D1 Mini to provide five water levels, water temperature, and activation of an irrigation valve.

Tested all 6 with a continuity tester, all 6 worked with varying activation distances [2-5mm of float drop].Bought these as coolant level sensors for a CNC system retrofit and will update as needed.Recommendations for use:Limit voltage to <150V. Limit current to <20mA.If you need to control more power use them to switch a MOSFET or SSR [Solid State Relay].

Installed in auto water dispenser for i gallon water container for dog. When water gets very low the contacts close and a buzzer i rigged up goes off.

The sensors themselves work great so far and seem reliable.There are no instructions on how to properly install this so I had to dig around and look at other similar products and installation photos to figure it out. The photos show the silicone gasket backwards from what actually works. The flange goes on the inside, through the hole, then the nylon washer goes on, then the nut. These create a watertight seal on both sides.

I installed the first float switch and it tested satisfactorily. The next day, my computerized water well system notified me of an issue. The float switch contact failed to close when the water tank level dropped. I had to tap the float switch in order to get the contact to close. I tested the remaining switches and out of the 6 float switches, 3 tested bad with a multimeter, out of the box. I am using these in a 24VDC circuit with minimal current draw, and of course, checking them with a multimeter certainly won't use enough current to damage them. All three bad switches had the same issues. When the float was lifted, the switch opened, every time. When the float was lowered, the switch remained at a high resistance, until I thumped it with my finger, then the contacts would close. I don't have much faith these will last very long, and I don't recommend this product.

I installed and soldered up the first one to alert me when the hydroponic nutrient tank was low and it immediately stuck closed. Ugh! I had checked it before installation and it worked as expected. I disconnected everything and determined the switch wasn't switching when I moved the arm. I banged it a few times on the concrete floor and actuated it a couple of dozen times and it started working again. I reinstalled it and it hasn't squawked yet. I hope it will when the nutrients get low....