Leak alarm + text mssg. + solid relay

New here - couldn't figure out if this was the right place to post this. I keep a saltwater aquarium and I would like to have a controller that does the following:

  1. In event of a leak, the controller detects water through a sensor on the floor.
  2. When detected, an audible alarm is played.
  3. A relay cuts main power to my aquarium pumps (stopping most types of leaks).
  4. The controller, connected to the internet through my modem, sends a text message to my cell phone alerting me of the issue.

Can an arduino do the above, or is this just a pipe dream? If it can be accomplished, can someone point me in the right direction to get a build started?


Hey there, and welcome! :)

It sounds entirely possible.

Some things you might want to consider:

1: How will you detect water on the floor? I bet there are sensors that will do that for you, but I cant give you any advice in that regard.

2: see the arduino Tone library for generating an audible alarm signal: http://arduino.cc/en/Reference/Tone

3: Using a relay with arduino is easy. Just make sure to use a protection diode, and to drive the relay through a transistor. See here: http://www.arduino.cc/playground/uploads/Learning/relays.pdf

4: I'd probably take a different route with this one. Find an old mobile phone, and hook it up to the arduino, using the sserial2mobile library. I have done this myself, and it works well (using an old SonyEricsson z600). will send both SMS and email. see here: http://code.google.com/p/sserial2mobile/

If you are completely new to arduino, I recommend that you start out with some examples. Get them working, and as you get more experienced, you can start building more complicated systems.

Happy arduino'ing!! :D :D

Hey thanks! That's helpful. The phone idea is interesting, and I have a couple phones lying around. Would I need to have a plan through a carrier to get that to work, though?

I'll start reading up on the basics now.

Yeah, you'd need some sort of carrier for the mobile phone used with arduino.

I dont know where you are, but here in Denmark, there's a carrier that offers a free deal for the first 50 minutes and 50 SMSes every month.

For the mobile phone, you should look into what AT command set your old phones support. You will need a phone that supports SMS in txt mode (as opposed to pdu mode).

I guess you could accomplish sending texts through a modem as well, but that will also require you to be able to 'talk' to the sms service that you would be dialling in to.