If you're just starting out with it keep it simple, until you're comfortable and committed to the process before investing too heavily into it. Any container will do. First and most important thing, know your daily alkalinity consumption. Second, know your approximate evaporation volume. You can't exceed that in your kalk dosage. It's unlikely you will if you have a tank with low demand but it's worth mentioning. Set your doser to drip it in over the course of the day, or just the evening to help with dirunal pH drop. There are calculators out there to tell you how much to dose based on your tanks daily consumption. You can mix up as large or small a batch as you like based on your setup constraints or personal preference. Larger volume equals less maintenance frequency. It won't fall out of solution so don't worry about that.
Mix two teaspoons approximately or to be more precise 1.73g/L is the max that will go into solution at 25 degrees Celsius. Just dump it in and stir it. Some may settle out to the bottom, that's fine just leave it there. Keep your draw tube just above the level of the bottom so you don't draw that up.
The Kamoer pumps are a bit limited in there control and while you can control dose rate in continuous mode is unlikely a continuous slow dose rate at a low consumption will work out. Even at 1ml/min that's a gallon a day. You also don't want to dose overly fast either as you could experience localized abiotic precipitation. A simple smart power switch could be configured to limit dosing times. Overall it's a pretty simple and safe way to replace calcium and alkalinity in your tank
