# Water detection 20m away from the Arduino **URL:** \ **Category:** Sensors\ **Created:** [December 2, 2024, 10:47pm UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261 "2024-12-02T22:47:41Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![arduinoscharl](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/arduinoscharl/32/1098836_2.png) [@arduinoscharl](https://forum.arduino.cc/u/arduinoscharl)\ **Post date:** [December 2, 2024, 10:47pm UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261/1 "2024-12-02T22:47:41Z")
Hi, I searched both with google and here in the forum but haven’t found a solution yet. Hopefully you can help? My arduino is installed in a garden hut and shall activate a pump when water level in a tank that is approx 20m away reaches a certain level. I got hardware and software working fine in a test setup with short wires but when I connect the long cable (twin wires, copper ends hanging in the tank to short the circuit when both ends are in water) I assume there is too much resistance in the wires to make Arduino recognise when water shorts the circuit. Any ideas how I can get this to work is very, very appreciated! ---
**Author:** ![UKHeliBob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ukhelibob/32/215663_2.png) [@UKHeliBob](https://forum.arduino.cc/u/UKHeliBob)\ **Post date:** [December 2, 2024, 10:51pm UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261/2 "2024-12-02T22:51:20Z")
Welcome to the forum Are you using digitalRead() to detect the short circuit between the wires ? If so, then consider using analogRead() instead and set the threshold appropriately However, the bare wires are likely to corrode quite quickly whatever method you use ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [December 2, 2024, 11:03pm UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261/3 "2024-12-02T23:03:10Z")
The reality is you should be using a waterproof float switch to do the level testing! ---
**Author:** ![cedarlakeinstruments](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/cedarlakeinstruments/32/1128931_2.png) [@cedarlakeinstruments](https://forum.arduino.cc/u/cedarlakeinstruments)\ **Post date:** [December 2, 2024, 11:09pm UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261/4 "2024-12-02T23:09:07Z")
A float would be the simplest way. Since you already have conductive probes, take a look at the liquid level sensor project at the bottom of this page: [Thermometer simulator | theselittlemachines](http://www.theselittlemachines.com/) Sorry, I don't have page anchors set up or I'd provide a link straight to the right point. It's tuned to detect syrup. You can adjust the settings in the code for water conductivity, it's a simple change. ---
**Author:** ![Ron\_Blain](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ron_blain/32/1126393_2.png) [@Ron\_Blain](https://forum.arduino.cc/u/Ron_Blain)\ **Post date:** [December 2, 2024, 11:13pm UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261/5 "2024-12-02T23:13:13Z")
If I measure common tap water with two standard VOM probes with probes about an inch apart I get about 500 Meg Ohms. Sixty meters is about 200 feet. AWG 18 copper wire has a resistance of about 6.5 Ohms per 1,000 feet or 60.9 meters. I do not see where the added resistance of the wire should matter much. What gauge wire are you using? You are sure your connections are clean and tight? I just doubt your wire length is a problem. Can you please post a schematic of your circuit. Ron ---
**Author:** ![Nick\_Pyner](https://avatars.discourse-cdn.com/v4/letter/n/e8c25b/32.png) [@Nick\_Pyner](https://forum.arduino.cc/u/Nick_Pyner)\ **Post date:** [December 3, 2024, 12:42am UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261/6 "2024-12-03T00:42:23Z")
![IMG_20241203_113503](https://europe1.discourse-cdn.com/arduino/original/4X/9/1/e/91ef7374ff091847e1acdfb5a82745f13d4d829d.jpeg) A proper float switch like this costs about a dollar. ---
**Author:** ![paulpaulson](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paulpaulson/32/363643_2.png) [@paulpaulson](https://forum.arduino.cc/u/paulpaulson)\ **Post date:** [December 3, 2024, 5:53am UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261/7 "2024-12-03T05:53:31Z")
> [@arduinoscharl](#): > > Any ideas how I can get this to work is very, very appreciated! Hello [arduinoscharl](https://forum.arduino.cc/u/arduinoscharl) Welcome to the best Arduino forum ever 🙂 Use a wireless connection simply. Take a view to get some ideas. > **[HC-12 Radio Module • Wolles Elektronikkiste](https://wolles-elektronikkiste.de/en/hc-12-radio-module)** > > The HC-12 module is easy to handle and has a long range. I will show you how to make the settings and how to use it in a legally compliant way (in Germany). ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [June 1, 2025, 5:53am UTC](https://forum.arduino.cc/t/water-detection-20m-away-from-the-arduino/1328261/8 "2025-06-01T05:53:45Z")
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