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I've been toying around with the idea of automating the process of testing aquarium water for certain chemicals. Very briefly, salt water aquariums (reefs, specifically) require almost-daily testing for 3-4 chemicals (calcium, alkalinity, ammonia, phosphate). This is typically done by hand, using various kits. There are two main types
- you combine several powders with a fixed amount of aquarium water, and then compare the color the mixture turns with a chart
- you combine several liquids together with the aquarium water, and then add another liquid until the mixture turns a color. you then record how much of the final liquid you had to add for the color change to occur (titration).
Both methods are straightforward, but tedious. To maintain an aquarium well, you really do need daily readings of all of those metrics, which easily adds up to 30 minutes+ daily.
So - I'd like to be able to automate the process. The biggest question is, how do I reliably dispense the materials needed? We're talking in gram and milliliter UoM here. The kits come with plastic syringes and spoons of correct volume for the powders. I need a way to measure out and dispense both of these, and a way to queue up several days worth (refilling daily defeats the purpose).
Edit this is different from How to measure and dispense a finite amount of powder or liquid because of the units of measure involved. I need to be able to reliably dispense ~ 1g +/- 5% of a powder, or 1ml +/- 5% of liquid.