Cindy Achieng

Updating the water flow sensor system

A few weeks ago we decided to update the water flow sensor system. The water flow sensor is an important fail safe system that gives us real-time data of the water flow rate. This is important because from this data, we can infer if there is biofouling in the pipes (forming of solids on the surface of the pipes). These solids can be from the fish waste, microorganisms or algae. For example, a few weeks ago, we had an increase in algae growth and the pump failed frequently; if we had the water flow sensor data, perhaps we would have been able to see a correlation between the two. The water flow sensor is programmed to send an alarm when the flow rate is below a certain value. An alternative is of course, receiving a message from the power alarm when the pumps fail, rather than an alarm from water flow data. We like to have both for redundancy and to decrease our response time when the system fails.


Having said this, let’s get into the work we did.


First, we replaced the previous flow sensor. We then programmed an Arduino MEGA microprocessor to receive and read the data. Arduino MEGA was then interfaced with Arduino Ethernet Shield to push that data to the internet. From there, the data was passed through pushingbox. From pushing box, it was passed through Google Script and finally stored in Google Sheets.


process -

Previously, we used xively but decided to change to Google Sheets because it is free and reliable.


The result is that we now have real-time data uploading to Google Sheets every 30 minutes and an alarm is sent to our phones whenever the flow rate is below 250L/h. Here's the link to view the data in real time.