Calcium Test Kit Results

[clowndude]

Today I used a hanna calcium checker and a red sea calcium test kit.

Here are the results:

Red Sea 415 calcium
Hanna Checker 550 calcium

Now the question is which test kit should I rely on. I use pure RO/DI water with zero tds and use Red Sea Coral Pro salt. I don't dose calcium as of yet because I'm trying to determine what my tank is consuming weekly. As you can see from the results I'm not sure which test to go off of.

 

[doctorgori]

Check out the Hanna forum, there is a long thread on the Ca checker...
also a knowledgeable hobbyist has a modified procedure that may help

 

[bertoni]

I'd check in the Hanna forum, but the Red Sea should be something like 490 ppm out of the box.