Hey everyone! There has been a lot of talk these days about the options of automated Alkalinity monitors. The benefits of these is easily seen but the price tag, other required controllers, and honestly the looks of some of the options out there have me reluctant to invest quite yet. So I got to thinking, and since I already have some experience with Arduino/RaspberryPi and all sorts of components, could I make one myself? I have not taken the time to really try and figure out how the current market devices are doing their calculations but assume it's something similar to what I am trying for here considering it's a (seemingly) common scientific process. There was a R2R article actually by Randy from way back in 2015 in fact on how you can do this. So it begins.... General project plan: - The process is to essentially take a ph reading of regular tank water, add a standard acid until ph reaches a set level. Once the pH level is reached, perform a calculation to get an outcome of the tank dKH/ppm of Alkalinity. - So, given the method above, here is how I envision this working. Peristaltic pump (1) pumps in sample tank water to a glass container. Amount pumped in is determined by a IR sensor that detects each drop and calculates volume based on drop numbers. pH probe is positioned to read the sample tank water as the container is filled. Likely waiting for a few minutes to take a level reading. Peristaltic pump (2) pumps in a basic acid while pH probe monitors the sample. Again, the amount pumped in is determined by a IR sensor that detects each drop and calculates volume based on drop numbers. Once the pH reaches the desired level, do the required math to determine dKH. Once dKH is determined, peristaltic pump 3 pumps out the water from the container and pumps in tank water as a 'flush' of the container. Once the container has been flushed, Peristaltic pump (1) fill the container to keep the pH probe wet. Depending on testing, this might happen from time t0 time to compensate for evaporation. Still Unknown How much is the minimal amount of wasted water to avoid constantly emptying a waste container. How fast can I run the tests. This is going to depend on how fast I can pump water in while still counting individual drops accurately with the IR sensor. Most pumps also have a minimum speed before the stop pumping liquid so hopefully that will not also become a problem. How to properly drain the container, right now I am thinking a metal syringe tip position as close to the bottom as possible. As a backup, I might look at using a container with a bottom hole but my thinking is that might affect sample accuracy since liquid would be in the pump line. Perhaps this alternative way could eliminate the need for the 3rd pump. Wiring Diagram This is my initial wiring thinking. I am certainly no electrical engineer so will be looking for feedback on this and likely will find someone smarter than I to give final okay on this. Until final approval from someone more qualified than I happens, you assume all risk using this long term for the time being. Remember, water and electricity are dangerous in combination. If you want to help out in the earlier days of this project, great, just please be smart about it. Licensing I'm a huge fan of community development of products. So beyond hoping that some experts here will help with the project itself, I want others to learn and build on top of it as well. Because of this, I am starting under the Creative Commons BY-NC-SA 4.0 license. Put simply, use and remix as you see fit but give those who helped make this happen credit. And you, nor I, can make money off the project directly.