As
@Diamond1 mentioned, most of these can be done except salinity monitoring. I intentionally punt on it, since its expensive, requires frequent calibration and I could not see a compelling reason to have it (compared to other features). If you are new to electronics, I would also recommend to start simple and aim for multiple controller instead of one thing that does all of it (to keep circuit complexity at minimum). The dosing pump control will be improving in coming days to include stepper motors and few other goodies. Salinity monitoring has been a constant ask for the community, and if I get extra time then I might shoot for it in our next release cycle.