simonc
Use the spreadsheet in my signature.
Put the Ca and Mg values given on the bottle and the bicarbonate in the bicarbonate bit….if bicarbonate isn’t listed but alkalinity is just put that straight into alkalinity box. Put your brew boiler temp in there (figure it out from viewing the offset in the pid settings + your brew boiler temp or look at the pressure gauge and figure it out from that). I imagine lockhills will not scale in a brew boiler but I’ve never actually checked.
Service boiler is the same. How you estimate when to drain is based on how often you steam and how much water gets used when you do. The second page can calculate how often you’ll need to drain if you actually know that but it’s difficult to figure out. Most just draw off water every week and refresh the boiler every month. You can test the water you pull off with a drop test kit to get an idea of how quickly it is becoming saturated, and assuming you have some kind of regular routine/use of the machine, just empty the boiler as often as required based on those tests. If it is scaling to start with then you can figure out how much scale is deposited per litre in mg/l but I don’t know what use that would be, really you’re just looking at scheduling descaling, whether regular and light or irregular and hard.