I would guess the Alk is way too high or your Magnesium levels are not where they need to be. If Mag is lower than 1200, you will never get calcium levels where they need to be. I use Salifert(CA,MG,SR),Seachem(PO4,Iodine,Nitrite and Nitrate,MG,SR) Tropic Marin(CA), Instant Ocean fast tests(Alk and PO4). I am looking to switch to the LaMotte tests, to see how I like them, when I need new kits. There has been some debate about reliability of the Salifert kits.
Matt