Are you planning on dosing
Mg too? I doubt you will be able to get the
Ca level in
FW above 350ppm without adding in
Mg even if you get the
alk around 8dkh.
Honestly, I've never attempted what you are doing. You are more than welcome to try but I think you may find that it will be much simpler to use
Kalk and then dose the tank if needed.