Has anyone ever had your tank not use calcium & magnesium. My calcium Is 530 and magnesium Is 1610. I have not done a water change in 2 weeks and it's not going down. Last time I did a water change my calcium was 510 and magnesium was 1600 before I did the water chance. Instead of going down it's going up??? Alkalinity is 8.35 dkh. Any ideas would be great I have mostly zoa's but have some hammers, and frogspawns, also have some gloves and xenia. Everything is growing and doing great well accept my candy cane that I just added to my tank a week ago. My tank is fairly new started it first of June, it's starting to show some purple coralline algae finally. is everything as it should be? I'm kind of new to corals, I've had fowlr tanks but this is my first time with corals.