Partnering with Akvo

Integration with Akvo FLOW

Water quality testing is very important. We all know that Fluoride, Arsenic, among other contaminants, are harming millions of people in India and around the world. We see Caddisfly growing to become an indispensable tool for communities to manage their water resources. To get there, we need to do several things – finish development of the Fluoride tests, build other tests, work on our communications, find customers, build distribution channels, handle sales, handle support, handle training.

This would have been a little overwhelming, if it were not for our partnership with Akvo. Since January 2014, Akvo has been helping us along in the development of Caddisfly. By integrating with Akvo FLOW, we have our data gathering and mapping solved. We actually tested this integration in our field testing with the Fluoride Network. Akvo works with several partners in the water and sanitation sectors that could potentially use Caddisfly.

Akvo and us share two crucial values – commitment to open source and a flat organization structure. In addition, we took 10 months to see how our teams get along.

What difference will this make to Caddisfly? Firstly we hope this partnership will speed up development and bring the product to market far sooner than we could have done by ourselves. Caddisfly will be closely integrated with Akvo FLOW, and we hope to benefit from Akvo FLOW’s continuous improvement. Caddisfly will continue to be open source.

Field testing at Jhabua

Workshop on Fluoride by FKAN

The Fluoride Knowledge and Action Network had a five day workshop on Fluoride and Fluorosis near Dahod, Gujarat. Sunder of INREM Foundation, who facilitates the FKAN, thought it would be a good idea for us to mix the workshop with some field testing around Jhabua, a tribal district in Madhya Pradesh. INREM Foundation has been working there for several years educating people about Fluorosis and facilitating interventions like filters, nutrition supplements, nutrition gardens, and a whole lot of other things. Especially touching, though hopeful, was the story of Neelesh, a child with Fluorosis, with a near miraculous improvement.

We did get to meet Neelesh at his school in Jashoda Khumji village at Jhabua during the course of our field testing. We took samples from handpumps, open wells, defluoridation plants and talabs. Rather shockingly, we found that defluoridation plants did not seem to be working in most cases. A solar defluoridation plant at a school where children regularly drank from had Fluoride in excess of 8 ppm. Far better were simple and inexpensive activated alumina filters supplied by INREM. All of them had removed Fluoride to less that 0.5 ppm.
Obviously, this being our first field test at scale, we learned a few valuable lessons. The test itself looks good. However there is a lot of work that needs to be done around the kit and the testing experience, especially on the field, where one would be hard pressed to even find a reasonably flat surface to place the phone on.

This video shows a typical test where we tested the water of an open dug well. Ramsoor, a tribal farmer, talks about farming, mahua, and drinking water in his village.

Simplifying Caddisfly

Making better use of the phone

We have significantly changed the architecture of Caddisfly. This post tries to explain these why these decisions were made and how it impacts the product. Caddisfly continues to be in development, though we now have a very good prototype for a Fluoride test.

At its heart, Caddisfly is a colorimeter. Red, green and blue LEDs flash and a photodiode measures the intensity of the the light as it passes through sample mixed with reagent. The microcontroller then matches this RGB value against a set of calibrated values and then sends the result to a phone via bluetooth. This process is illustrated below.


This is a very simplified process of what goes on inside Caddisfly. There are several challenges that need to be addressed here.

Firstly bluetooth is fickle at best. There are good chances that future users will run into trouble trying to get data off Caddisfly and onto their phones. This would have undermined one of our key promises – real time data aggregation.

Secondly, we could not control all factors involved in the circuitry, components and casing to give us consistent readings. This simply meant that we would have to settle for calibrating each device individually rather than one calibration for all devices.

Thirdly, adding new tests was going to be difficult – involving hardware changes and firmware updates. As of now there was a one way communication between device and phone, would we have to add the extra complication of firmware updates from the phone to the device?

Most importantly, we had to create dies, moulds, PCBs and electronic assemblies in order to build and ship units. That meant goodbye to our inexpensive, rapid iterations. We would have to come up with a design and stick with it. But without the investment up front, we just would not get traction.

Let’s look at what we had at this point: A colorimeter, a cartridge system, and ideas for a dispensing mechanism. As a concept this worked very well – it was just that there were several practical difficulties in execution.

At some point in October 2013, we realized that we were overlooking something obvious. All smartphones come armed with very good cameras, and a camera is a very sensitive color sensor. Designing the rest was simplicity itself. The Indian market is aflood with inexpensive phone back cases – usually made for each model. It was a fairly simple task to a mount our cartridge to the back on the phone, positioned over the camera using these back cases and using the camera and flash to take pictures. We rewrote the android app to perform colorimetric analyses from these pictures.


What happened was that we were able to make and test tens of kits. We could also rapidly iterate rapidly since the parts were fairly simple and inexpensive to fabricate. In fact our first few prototypes were made almost entirely of PVC plumbing pipes and fittings.

We have now eliminated massive complexity from the product. No bluetooth and no electronics. However there were a few areas that remained to be addressed.

Remember the dispensing mechanism that we glibly passed off a few paragraphs ago with “ideas for a dispensing mechanism”? Well we now had to address it, and that brought its own challenges. However, not having to worry about hardware and electronics meant that we could give it more attention.

Phone cameras and flashes, we have found, are hugely variable. There are some models on which Caddisfly stubbornly refuses to work. On others, colors are just awful. We may have to come up with a whitelist of phones that Caddisfly works on, and perhaps a shorter list of recommended phones. Also, because of camera variability, each phone will have to be calibrated individually. We are working on how to ease, simplify or remove this step.

Which brings us to where we are now. We have a fully functional prototype for the Fluoride test, which has been lab and field tested. There’s still some work to be done to make the test more accurate and repeatable. As mentioned earlier, we have to work on simplifying calibration.

The Water Crusaders

Named after the bio-indicators of pure water - caddisflies, which are flies that inhabit clean water - the product is a water testing kit.

“With millions risking fluorosis and arsenic poisoning around the world, the four brains believe that the first step to address this issue is reliable testing of water.” writes Shyama Krishna Kumar about Caddisfly in The New Indian Express.

Read the story here.

We are Mint’s ‘Cool Startup’

"...tackling some of the most pressing water & sanitation issues in India..."

“The founders of TernUp Research Labs LLP avoid titles – Arun Kumar jokingly calls himself ‘chief bullshit officer’. But they take their work seriously and they are tackling some of the most pressing water and sanitation issues in India, problems most start-ups shy away from.” writes Mark Bergen.

Read the full article at Live Mint