What type salt mix are you using? I`m thinking with that reading it`s Instant Ocean. You might have to supplement calcium with that salt mix. Not that IO is inferior to any other salt mix. They have their pros and cons. I use Oceanic which keeps my calcium around 450-480. But the con for that is the alk
is kind of low. Let me know what type you are using and I know that alot of folks use some type 2 part calcium solution but I cant remember what the name is. Maybe kurt will see this and let us know.