I think Salifert have changed the Ca kit as mine just arrived today and only has one bottle of solution and the instructions make no mention of a Ca-3 bottle. The instructions are also a bit rubbish in that it tells you to add 0.6ml of Ca-2 in one go then add drop wise until colour changes pink to blue. I did this, but colour was already blue. I then realised 0.6ml equates to 300 ppm Ca whereas my water is around 30. I did it again and this time just added dropwise from the start - it changed after adding only 0.06ml sp bang on 30ppm.