How to use API calcium test kit?

[Davoaldo]

I just got a calcium test kit from API and i am not too sure on how to use it. Can anyone help me?

I don't get what point 5 and point 6 of the instruction is saying?

Does the whole tube of liquid have to be blue to be the end point or when the drop hits the solution it turns blue?
What if it slowly turns blue?
My solution never seems to turn blue whenever I shake it will will turn to pink.

What am i doing wrong?


5. Holding the bottle vertically, add Calcium Test Solution #2, drop by drop to the test tube until the solution changes from pink to the blue end-point. Each drop is equivalent to 20 mg/L (ppm) calcium (Ca2+). Cap and shake the test tube between drops. Be sure to count the drops added.
a. A pink color should form after the first drop.
b. If a blue color forms after the first drop, the calcium concentration is 20 mg/L (ppm) or below.

6. As the end-point is approached, the color will usually change from pink to purple before finally changing to blue. After the purple color forms, only one or two more drops should be required to reach the blue endpoint.

[sjm817]

Keep adding till it turns blue. It can be many drops. If your calcium is 440, its 22 drops. It will turn from pink to purple to blue. # drops X 20 = ca level.

[Davoaldo]

What if I have added more then 22 drop and its still pink?
My tank is pretty new and I never added calcium in it can this be possible?

[dsn112]

If you have nothing in the tank really using the calcium it could be. Are you flipping the capsule to mix it during the drips? I usually add about 18 drops, then flip it. then i flip every drop after until i get the purple color.

[Davoaldo]

Yes i am flipping it every drop.
I've only got 4 chromis and a dottieback in the tank no corals at all just rocks and DSB.

[dsn112]

My first tests before any corals was around 500ppm using Instant Ocean mix

[sjm817]

Could be your ca is high. What kind of salt?

[Davoaldo]

I am using Seachem marine salt it came in a bucket load.

[sjm817]

Keep adding drops till it turns blue and post back the number.

[Davoaldo]

I just finishing testing both calcium and dkh

Cal is 560
and dkh is 15

Is this weird or normal?

[sjm817]

That is high on both of them. Is your SG too high? Did you mix your salt using a calibrated refractometer?

BTW, I would not put any livestock in the tank until you get this figured out.

[Davoaldo]

I mixed the salt with a floating device, hydrometer i think.

Its currently sitting at 1.025.

What will happen if the Cal and dkh is too high? Will things die?

[sjm817]

Odd. Range for alk is 7 - 11. 15 is really high. I would post this in the chemistry forum and see what they think.

[stingythingy45]

I'm willing to bet that if that hydrometer was checked against a refractor your water would be 1.028-1.029 SG.
And you MG would be 1550 ppm or higher.

[sjm817]

Yeah, get another SG reading.

[Nanz]

• Use a 5ml Syringe to place the sample in the testube.
• Always clean the testube and cap with RODI and a brush.
• Always shake reagents prior to using.