Why Ca++ Test kits Don't Change to Blue
I am using Aquarium Systems Calcium test kit for my reef tank. I can never get blue as the end result, it stops at purple. I called Aq.Sytems 1-800 help line and actually got through to a tech. support person. He told me this happens to about 10% of the people that use calcium test kits and it's because my salt water is too dense. I told him I keep it at the recommended 1.022 specific gravity. He said that's not what he meant by too dense. He explained the specific gravity of my water is fine, it just has too many minerals in it that are inhibiting the color change to blue. I asked if he thought my magnesium was too hi, and he said "no, it is precipitated out with the reagent that has the small dropper." He told me to dilute my test water in half with either ro or di water and then take a reading. He was right. I tried it and the color change to blue was dramatic and unmistakable. I guess this guy knows what he's talking about. So if any of you have trouble with a color change to blue, you now know why. If you have any other ideas , please let me know.
Thanks, Dick Lutman
I am using Aquarium Systems Calcium test kit for my reef tank. I can never get blue as the end result, it stops at purple. I called Aq.Sytems 1-800 help line and actually got through to a tech. support person. He told me this happens to about 10% of the people that use calcium test kits and it's because my salt water is too dense. I told him I keep it at the recommended 1.022 specific gravity. He said that's not what he meant by too dense. He explained the specific gravity of my water is fine, it just has too many minerals in it that are inhibiting the color change to blue. I asked if he thought my magnesium was too hi, and he said "no, it is precipitated out with the reagent that has the small dropper." He told me to dilute my test water in half with either ro or di water and then take a reading. He was right. I tried it and the color change to blue was dramatic and unmistakable. I guess this guy knows what he's talking about. So if any of you have trouble with a color change to blue, you now know why. If you have any other ideas , please let me know.
Thanks, Dick Lutman
