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Alarm System for Monitoring a Pond
I need to monitor a few ponds, the temp, oxygen level and flow rate into it. Not sure what to use.

I need to monitor a few ponds, the temp, oxygen level and flow rate into it. And send SMS when they reach alarming levels. And readings be accessible from remote location.

Looked into sensors, thinking about using 4-20ma or pulses.
I know there are modules for 4-20 to ethernet.

Initially, I thought of the sensaphone 3000, but I am not really controlling anything just monitoring and alarming.

Is there any recommendations? Kinda new to this.


For the data collection and SMS end, Google "datalogger" and make some calls. What you describe has to be a commercial package by now.

I am very interested in helping to encourage folks to solve such projects with simple tools that are easy to use!

Where in the world is your remote (pond) location? How far away is it from your office (or another site with people & computers)? First phase is to determine what your options are for communicating with the remote location. Once you are communicating there are many other options, some of which are summarized here:

Best regards,

You've gotten some informative replies Edward! I'd like to share a few more thoughts.

If you use cellular there are warnings in this message thread:

At the page I linked in my previous message I hope to show the most simple ways that I can find to monitor temperature (locally and remotely). If WiFi is available you can use an inexpensive Raspberry Pi Zero. Moving up the ladder you might want to check out the Waspmote which is an industrial Arduino! Thankfully there are lots of options.

By Bob Peterson on 25 May, 2017 - 4:06 pm

My opinion.

Stick to standard 4-20 mA transmitters.

Plenty of comm options. Cell data. landline. Plenty of dirt cheap PLCs with analog inputs these days and free software.

A lot depends on what you want to do, how often you need to send the data, and what comm options are actually available where the pond is.

Hi Edward,

A 4-20mA wireless system is a good way to go. The SlideShare presentation at

on wireless sensor networking. slide 14 shows an overall diagram of the concept that you can use. if the ponds are all within a mile line of sight of each other. There would need to be environmental packaging of the ROI-RFX 4-20mA modules, local (or solar) power, and antennas (and masts if line of sight is not clear). Instead of the Wi-Fi connection a cellular modem can be substituted. This would require an ISP or cellular provided (based on which of 2 methods used), online data storage, plus an application to read the data and set up the SMS messaging. If each pond is quite distant from another, it may be necessary to configure the system with multiple cellular modems. We can help you get it going, if you would like to discuss it.



Thanks for the reply guys.

The pond is less than 500m away from the office with internet connection. But there are a lot of trees and barriers along the way so can't dig a conduit.

The problem is there won't be workers there all the time. And they need to know if the alarm goes off so they can come down and fix the problem.

Not too sure about frequency. Just enough time to notify workers so the wildlife in the ponds won't die. At least every 30min I'm thinking.

there are also closer smaller tanks for fishes too, but these are in the building close to the office. I can run a conduit for them.

Main thing is alarming notification and logging data. (I did look up datalogger)

Was just looking for easy to use alarming ideas.


Hi Edward,

So if the distance is 500m, you may want to still look at a wireless connection, as that is a lot of wire and conduit. Take a look at page 8 of the same SlideShare presentation

and it will show how 2 wireless modules (transmitter + receiver) can be used to transmit long distance from a local PC. Wireless is a good way to not only save conduit & wire, but also jump obstacles.

A reading every 30 minutes is no problem, you can get a couple of readings a second or as slow as you need.

In regards to getting the readings from it; programming is easy enough for any programmer, but for non-programmers there are simple applications e.g. Keyboard Wedges, from a number of companies that will work with it. A link to an example is

for a discussion of a data recorder application that should make the job simpler.

If you are able to use Microsoft Office Excel, VBA can send an email message. The trick in sending it to a Cell Phone as an SMS text is to know the cell phone providers format is how you would do it for ATT. I just added it to a spread sheet now and tried it, worked fine to the phone and cc'd an email account.


Dear Edward,

Simple solution for your case is below.

Use oxygen meter, Temperature Transmitter & Flow meter. All instruments with 4-20 mA transmitter.

Give your 4-20 mA to our data monitoring system.

and your data will be in your laptop or mobile phone within second.

You can monitor from anywhere. visit below website for more details.

I just updated this morning after quickly getting a console Debian installed on a RPi Zero Wireless. This is a very neat way to start with inexpensive hardware!