Difference between Ca test kits

[barracuda]

I was used to use Ca test kit by Red Sea. With this test i was measuring Ca about 400-430. Las week i have bought test kit by Hagen. It showed me 560. I remesured with Red Sea and it was 400. So, i don't know which one to trust. Somebody had this kind of problem?

 

[mini-reefer]

Uh oh. Ive got a Red Sea Ca kit. I hope there isnt that much of a variance between two different manufacturers. <img src="graemlins//eek.gif" border="0" alt="[eek]" /> Not to be a smart a@#, but are you sure that you followed the Hagens instructions? I have found myself testing with memory on drops and procedure after changing test kits and fowled up the results. Then it will dawn on me what I did and re-test the water. Just curious here.

 

[frankl15207]

I use either the Red Sea or Salifert depending on my mood. Outside of the fact that the Red Sea test has higher ranges (ie 1 drop = 50), Both tests are always within 20 of each other.