Water quality testing, on a smartphone

What is Akvo Caddisfly?

It’s a simple, low cost, open source, smartphone-based drinking water testing system connected to an online data platform.

Existing features of the phone combine with software apps and pocket-sized hardware attachments, to conduct reliable tests on water samples and then share this data with the people who need to see it.

Akvo Caddisfly has already been beta tested at scale in Africa, Asia and Europe. It will be widely available in early 2017.

Why do you need Akvo Caddisfly?

Current water quality testing systems can be hard to use in the field, and lab-based tests are expensive and cause delays. Resulting data is generally difficult to share making it hard to act on it quickly and to engage communities who don’t know about problems in their local water supply. 

Smartphones transform water quality measurement, making results accessible in real time. Testing can scale up on a very affordable basis, with data immediately accessible and shareable via an online dashboard. It can lead to faster, better interventions and action. 

Because it’s cheap and easy to use, citizens may eventually be able to test their own water supply, thereby democratising data collection.

What tests will Akvo Caddisfly perform at launch?

  • Fluoride 

    66 million people are at risk from fluoride in water in India alone. 

    How does it work? 

    Add a reagent to a water sample in a testing chamber attached to your smartphone or a special external camera connected via a USB cable. A photo is taken to detect the colour of the sample. This lets the Caddisfly app calculate the fluoride concentration of the sample.

  • Salinity – EC sensors

    Find out instantly if water is drinkable or suitable for agricultural and irrigation purpose.

    How does it work? 

    A sensor attached to your smartphone via a USB cable is used to measure the electrical conductivity (EC) of water. This indicates the water’s total dissolved solids (TDS) or salinity.

  • Any strip test 

    Investigate pH, nitrate, nitrite, phosphates, iron, chlorine, or any parameter for which a strip test exists. 

    How does it work? 

    Dip the test strip into water, position it on a colour calibration card and photograph it with your smartphone. The Caddisfly app interprets the colour of the test strip and calculates the test result.

Viewing, mapping and sharing data in real time

Real time data is shared via Akvo’s data collection platform Akvo Flow. Water quality testing can be easily combined with other base line mapping and monitoring activities and can be viewed and shared online in maps such as this one, thanks to the smartphone’s GPS. 

Looking ahead

The prototypes for the fluoride, EC-sensor and strip tests are now being fine-tuned and readied for manufacture at scale. We’re currently seeking investors to mass-produce them from early 2017. 

We’re already researching and developing new colorimetric field tests for arsenic, coliform bacteria, chlorine and turbidity as well as stationary EC-testing sites. Real time data from these stationary EC-testing sites will be automatically uploaded to an online data platform where they can be visualised in graphs.

Get involved

Do you have some knowledge to share? Would you like to take part in Beta tests? Can you help us fund Caddisfly’s rollout?

About Akvo Caddisfly

Akvo Caddisfly is an open source, smartphone-based water quality testing kit that combines simple, low-cost robust hardware with the Caddisfly Android smartphone app and Akvo Flow, our field data collection platform. 

Akvo’s R&D facility in Bangalore is home to the Caddisfly development team. From here we work with a global network of partners to test the tools, in laboratories and in the field. Testing and developing partners include SNV, the Fluoride Knowledge Action Network (FKAN), ICCO, Acacia Water, UNESCO-IHE, TUDelft, Aqua for All, Indian Institute of Science (IISc) and IIT Kanpur.


Partnership with SNV 

SNV is the lead funding parter for Caddisfly and a global strategic partner of Akvo. Its investment has enabled us to accelerate Caddisfly’s development. SNV intends to scale the use of Caddisfly in its own water, sanitation and hygiene (WASH) and agriculture programmes worldwide.