How to make DIY Water Detection using Arduino??

Hi My name is Raash and I’m newbie for arduino. I want to make DIY Water detection using Arduino. I have check many forum regarding this topic. One of the related project that I found is How to Make an Arduino Water Detection Alarm at I have follow all the instruction as in the above forum and build the exact circuit as shown above in forum to make water detection using arduino but it doest not work for me. The circuit just can’t overcome the resistance of the water.

What might be the problem

  1. I think the 5v power source is not enough and though want to increase the power source to 9v or 12v using external power source like battery but I scare this will burn the arduino uno board

Below shows the image of circuit of water detection using arduino from the forum How to Make an Arduino Water Detection Alarm which extracted from

Can anybody help me how to solve the problem?

Try 100K instead of the 10K.
OPs Fritzy

Tom… :slight_smile:

Why use an arduino, a darlington-pair transistor will do that job perfectly

Try one of these $2 sensors, just plug in and go.

Detects , wet ,dry and anything in between.

TomGeorge as you said I used 100k resistor and it working. Can you explain to me why 100k works but 10k doesn't works?

If the wires need to stay wet indefinitely, I will look for a better solution. Otherwise, they will corrode overtime.