Water test kit matrix

@juanmagararc and I started a google spreadsheet to compare different commercial test kits that people in the GOSH community are using (chemical, test strips, etc.). If anyone else is into water testing (e.g., people who participated in the water quality workshop at GOSH2018), please feel free to contribute.

7 Likes

Hi! A very beginner question related to water testing and the test kits. I have just become interested in diy testing nearby lakes for coliform and toxic algae. Our city tests the water only in the summers, but I want to test it year round. It looks like the only commercial water testing kit listed in the spreadsheet that tests for bacteria is out of stock here. Does anyone have a guide or tips for testing for coliform? And for algae as well? Thank you!

1 Like

Oh I just found the thread on harmful algal bloom Harmful Algal Bloom here! Will look into that.

Paging @Rachel
Edit: found it

1 Like

sounds very interesting! we have mainly used the Roth cards for microbes in recent years, like I brought to Panama, but I would also love to be checking for harmful algae… Maybe metagenomics is better than a culturing method in that regard??

This has some of our latest lake water quality test info - trying to pull data for all our sampling years together now. The crazy thing is that last year was ‘cleanest’ - infrastructure work may have fixed a leak??? maybe we made a difference? =)

Do we have a list of open source water test equipment?

In particular does anyone know of an open pH monitor?

hi Martin
We have been working on two version of a phmeter with @pablocremades @Laraja and others from reGOSH. One mobile and another more simple lab bench version.
CoSensores have a few other devices to test water already working. Look here
You can look at Hacking Ecology for in field continuous monitoring
There is also this old thread with lots of information on water monitoring from @Markos and a great list of sensors from public lab from @gretchen I think

1 Like

Thanks, I had no idea there were so many options. I’m regrettably mono-lingual. Do you know if any of these are open source & could report back pH values to a Raspberry Pi?

I’ve also found Raspberry Pi compatible pH boards seem to be available from Atlas Scientific, Anyleaf, Homelab-pH, DF Robot and others. The Atlas Scientific seems to be mentioned most in my brief googling, but none appear to be open source.

Forgot to mention the iorodeo phmeter that is fully open
ours are open too… sorry about the language
and I think you can interface any of them with raspberry but you have to write the code for that

1 Like

That’s brilliant, thanks Fernando. In my particular application I’d like to have pH data report back to a Pioreactor, so I’ve posted about this on their forum too.

@Jorodeo & Will Dickson - I’m guessing the pH FeatherWing is your design. Am I correct in assuming it could be plugged straight into a Raspberry Pi 4+ rather than needing a Feather as an intermediary? If so, I’m hoping it could be integrated directly into a Pioreactor.

1 Like

Dear MartinC,

For pH, go to Section 10H of the draft copy of my maker e-textbook at
https://fit.instructure.com/files/48078947/download?download_frd=1
starting on p. 332.
https://www.ebay.com/itm/Liquid-PH-0-14-Value-Detect-Sensor-Module-PH-Electrode-Probe-BNC-for-Arduino/201758085638 is the cheapest source for pH probes and shields.
I order from them in bulk (60 usually) every two years for my class. DFRobot is plan B. Atlas Scientific is way too expensive, although I started with them about 6 years ago.
My class is available at
https://fit.instructure.com/courses/629658

The section after pH is for salinity (electrical conductivity) testing. For my research, I use a more expensive EC, a DO, and an ORP sensor as well
Most of the kit parts are linked to on p. 293. If you need more detail, just post more to the forum.

Best regards,
Jim Brenner

3 Likes

Thanks Jim, quite a comprehensive book. We’re prioritising open hardware & ease of integration with the Raspberry Pi based Pioreactor over absolute cost. We may need to spend >£200 on a micro pH probe just to get one small enough to fit into the 20ml Pioreactor chamber.

It’s great (amazing in fact) to know how cheaply you can get a pH board with a probe included, and we can recommend them to collaborators on the tightest budget.

Thanks @MartinC. I’ll need to learn more about the Pioreactor. I have been working toward an array of bigger bioreactors with a complete array of sensors and controls (pH, ORP, DO, EC, turbidity, several concentration sensors, pumps, valves, filters, automated syringe pumps, etc.) for a full mass balance, with the goal of miniaturizing later on when the cost of the sensors goes down. In terms of other features, we are working toward an incubator that can be integrated with a microscope and a fine positioning system to permit inexpensive live cell imaging under the presence of an electromagnetic field after dosing of growth and differentiation factors. I have also developed a very partial cytokine sensing kit, with the long term hope of measuring the full array of cytokines and building a proper control system using that.

1 Like

The real key to getting the cost down is to use IORodeo’s multiplexed Rodeostat to do the concentration measurements electrochemically. Thanks, @Jorodeo & Will Dickson. I gave Will the design to upgrade the Rodeostat to allow it to be multiplexed. That drove down the cost down to $380 for 7 concentration measurements. The other key is to use chromatography valves from Valco/VICI, which I was able to buy used in bulk (25 ten-way valves for $450).

1 Like

Wow, sounds amazing Jim. With my current Pioreactor setup I have a spectrometer in addition to the standard measures of optical density and temperature. The hope is that, to enable crowd open protein research at scale, we can keep cost & complexity to a minimum by focusing on a few key parameters. I assumed optical density would be the key parameter, but while it (plus OpenFlexure microscopy) gives a great indication of whether the bugs are happy, it doesn’t let you know why…

I’d love to know which parameters you find most useful & couldn’t live without?

Dear MartinC,
The most critical parameter is the lactate concentration. If that isn’t being removed properly, then there are very significant problems.
Good morning,
Jim Brenner

1 Like