Test Kits

[Lifwilend]

I currently have been using salifert test kits and have been pretty happy with the results I have been getting. However, I purchased a calcium test kit about a year ago or less and recently noticed the readings are skewed. I have been performing the test several times and have been getting different readings each time. The expiration date is 2011 so it couldn't be expired. Also, the calcium test process can be confusing. I have had some trouble determining the actual final result of the test. It seems that the color change process from the bright pink to the so called CLEAR BLUE color is very gradual and it passes through a purple color before it turns blue, OR is it blue or dark purple? Can anyone help me with this situation. I have considered changing test kit brands because of this.

 

[BLKTANG]

I go until its past the "purpleish" color drop at a time until it turns light blue.I hold the vial up against a piece of paper to be sure its blue.