Water Sensors

Many people interested in measuring various **water quality parameters** that are relevant to environmental health in low-cost and accessible ways. Many have been working on low-cost, open-source sensors for water chemistry and physical properties, and there are also several commercially available water sensors and analog tools that can measure relevant water quality parameters. [![IMG_20171205_145207.jpg](https://publiclab.org/system/images/photos/000/022/802/large/IMG_20171205_145207.jpg)](https://publiclab.org/system/images/photos/000/022/802/original/IMG_20171205_145207.jpg) ### Overview Often, electronic environmental sensors are just one part of a system that includes: * a [data logger](/wiki/data-logging) * some kind of [water and weather-proof enclosure](/wiki/sensor-enclosures) * a **sensor of some kind** -- see [Sensors](#Sensors), below And we also have to consider: * how to **configure the logging program** & **[connect to the chosen sensors](/notes/warren/12-06-2017/help-document-how-to-connect-different-sensors-to-a-data-logger)** * how to [download data](/wiki/data-logging#Download) * how to [visualize](/tag/visualization) data * how to [design experiments](/tag/experimental-design) using these techniques It's hard work writing good documentation. Let's team up and share as much of the above as possible -- many of these steps are either not device-specific, or are at least very helpful **if written in a way that supports use across projects**. **** [![coqui.png](https://publiclab.org/system/images/photos/000/022/801/large/coqui.png)](https://publiclab.org/system/images/photos/000/022/801/original/coqui.png) ## Getting started If you have never used an electronic water sensor before, try the Coqui project, which is specifically designed for folks who are just starting out. [Build a Coqui](/wiki/coqui) - a simple device to read a sensor via an audible tone. The Coqui is also a stellar example of how to document a project. (above photo by @akshaya) **** ## Choosing Sensors Often the first step is to **look for a sensor for what you're hoping to measure.** Below we're collecting info on different kinds of water quality sensors, and their: * cost * sensitivity/accuracy * links and documentation Can you afford a sensor? Can it detect what you're looking for? Where can you learn more about it? And here's a longer collection of many different sensors ([add to this list here!](/notes/warren/12-06-2017/help-collect-environmental-sensors-probes-on-a-shared-list)): See and [edit the full spreadsheet here](https://docs.google.com/spreadsheets/d/1UwjRqU8kHTwEcnDdO2Zxkr8zkFkaGfyePJ-cdnxJzw0/edit?usp=sharing) ### To be added * See this [great list of sensors from the KnowFlow](/questions/rockets/07-10-2017/how-accurate-is-the-probe) * [the Wheestat](/wiki/wheestat-user-s-manual) can be plugged into a datalogger * we should go through the above list and see which are Arduino-compatible - add to the "Interface" column * Figaro electronic #hydrogen-sulfide sensors [here](/notes/warren/9-19-2011/prototype-h2s-sensor) Are there others you're interested in? Please add them to the list here and to the linked Google Doc! (below are some not listed above yet) - transparency - chemical oxygen demand - COD - phosphate - total dissolved solids - TDS - Hardness - Lead - bacteria - fluoride heavy metal [prompt:text:ie temperature] **** ## Questions [questions:water-sensors] **** ### Connecting sensors Most of the [data loggers](/wiki/data-logging) on this site are Arduino-based (#arduino) while some are Raspberry Pi-based (#raspberry-pi). Vernier has a lot of good resources on connecting their Arduino-compatible sensors, with example code: https://www.vernier.com/engineering/arduino/ As we build out resources for connecting different sensors or different types of sensor interfaces (i2c, analog, etc), let's think about how best to list those guides and support materials here. Help add activities below for connecting specific sensors to [different data loggers](/wiki/data-logging), and pitch in on [researching how these connect here](/notes/warren/12-06-2017/help-document-how-to-connect-different-sensors-to-a-data-logger). [activities:connecting-sensors] **** ### Analog methods Even though this wiki page is labeled "water sensors," the most accessible modes of measuring water quality parameters are often **analog, non-digital methods** where you directly observe water (e.g. using a secchi disk to assess turbidity) or collect a sample and test it with a visual method (e.g. color-change pH strips). Several analog tools are included in the spreadsheet, and please add more! ### Hybrid approaches and enclosures In some cases, it may be possible to couple a commercially available **probe** sensor with a DIY **data logger** (such as the Riffle, https://publiclab.org/riffle) and an water-tight **enclosure** to create a lower-cost deployable sensor. Deployable sensors can be extremely useful for long-term monitoring, monitoring in places that are difficult to access frequently, or to document fluctuations in water chemistry with greater temporal resolution. ...

Author Comment Last activity Moderation
warren "I love this idea. Here are some leads on connecting a TDS meter to an Arduino, if that's what you're interested in: https://forum.arduino.cc/index..." | Read more » almost 6 years ago
warren "wow!!! This is very cool. Here's an amazon link: https://www.amazon.com/s/?tag=duc0c-20&url=search-alias%3Daps&field-keywords=tds%20aquarium " | Read more » almost 6 years ago
Ag8n "I checked Amazon. There are several tds meters that also do conductivity for a price of under $20. Since a scientific model lists for about $1000,..." | Read more » almost 6 years ago
Ag8n "Sorry. Truncated the internet address: Https://www.hydroponics.net/learn/debate_over_ec_and_tds.php " | Read more » almost 6 years ago
Ag8n "Check out: Https://www.hydroponics.net/lear All tds meters are conductivity meters, but according to the article, they may not all use the same c..." | Read more » almost 6 years ago
Ag8n "I think it is. Was hoping someone was more familiar than me. Different websites talk about charge and others about conductivity, which can be two..." | Read more » almost 6 years ago
gretchengehrke "Hi @Ag8n, Do you know how the aquarium TDS meter works? Maybe it really is just a super cheap conductivity meter? " | Read more » almost 6 years ago
Ag8n "Very interesting article. Thank you for posting it. Could you give more details on the turbidimeter you have developed? Regards " | Read more » almost 6 years ago
warren "And also see: https://publiclab.org/questions/gretchengehrke/07-19-2017/can-commercially-available-water-sensors-work-with-diy-data-loggers " | Read more » about 6 years ago
warren "@cfastie - i remember you highlighted a few different interfaces Arduinos can use -- i2c, analog... do many sensors fall into one of these categori..." | Read more » about 6 years ago
warren "We're going to try to collect this info on this listing of different sensors over here! https://publiclab.org/wiki/water-sensors#Sensors " | Read more » about 6 years ago
donblair "Hi @gretchengehrke! Sorry for the much-delayed reply :) and thanks for the comment. I, too, liked this approach -- basically, using the differenc..." | Read more » about 6 years ago
gretchengehrke "@donblair, I was just reading this again, and am again impressed by your elegantly simple approach -- such a great idea! It seems like this alterna..." | Read more » over 6 years ago
gretchengehrke "@bhikman, that integrated optical filter is neat, and surprisingly inexpensive! If you do pick this back up, I am super interested in seeing how we..." | Read more » over 6 years ago
bhickman "Hi @gretchengehrke. I kinda let this project fall though the cracks. I did have the sensor working pretty well, the only issue was interference fro..." | Read more » over 6 years ago
gretchengehrke "Hi @bhickman and @ggallant! I was just reading this research note and comments again, and it sounds like such a promising project. Are there any up..." | Read more » over 6 years ago
gretchengehrke "That's so great, Shan! " | Read more » over 6 years ago
shanlter ""Did the Chinese government state the methods they would use to evaluate each of these parameters?" yes, they state the standard methods. "Also, di..." | Read more » over 6 years ago
shanlter "Hi @gretchengehrke, sorry for responding late, I was in a temple with no internet access in the passing week. Yes, I've seen that page and I though..." | Read more » over 6 years ago
gretchengehrke "@shanlter, this is great! Have you seen the spreadsheet on the www.publiclab.org/wiki/water-sensors page? There are some other options there listed..." | Read more » over 6 years ago
rockets "yes, that's better than mines " | Read more » over 6 years ago
warren "Hi, @rockets -- maybe refining the title could be helpful here; I hope you don't mind but as I'm an admin, I changed it to How accurate are KnowFlo..." | Read more » over 6 years ago
rockets "The probe accurate is list below: 1 Gravity: Analog Electrical Conductivity Sensor / Meter For Arduino Operating Voltage: +5.00 V PCB Size: 45 × 32..." | Read more » over 6 years ago
jesseslone "@donblair I noticed you have a more recent post about turbidity, I was wondering if you would choose a different light sensor than the Adafruit one..." | Read more » about 7 years ago