Most likely youre dosing too much or your salt is just really high in alk and calcium. I think 10 dkh is great and i would keep it in the 9-10 dkh, it can get as low as 7 dkh and be okay, but I dont like to keep it there. Calcium should be in the 430-480 range, 600 is really high

you mentioned dosing b-ionic, doing this will raise calcium and alkalinity (if youre using both bottles). Dont follow the directions, just monitor your alk and calcium. If you have a reef that is really depleting both, then check every 3 days to see how your alk and calcium are and dose to the levels you want. There's a reef calculator on this board in order to find out how much to dose to bring it to a level you want. If it hasnt caused problems with your pumps or powerheads, I would leave it alone and stop dosing, or do a water change to bring it a little lower

If you dont have many corals or coralline that consume calcium, I wouldnt worry about it; youll probaby do fine with just doing water changes weekly