I received as a gift the Hanna Calcium tester. Having difficulty understanding the instructions. I read them several times and the instructions never tell you to take a sample of the aquarium saltwater? The first part is mixing with deionize water with chemical then appears to have you place in tester as c1 then add reagent and go to co2. I know this cannot be but I put the test kit up until I understand those instructions. What am I missing?
