I've been using the API calcium test for 8 months on my nano which was reading on average 400 ppm.
I've since setup my 90 gal with predominantly live rock, coral skeleton, and aragonite sand. My API test kit reads 420 ppm. I recently purchased a salifert bundle and tried the calcium test to compare. For some reason it's coming back with 490 - 500 ppm? I've done the test 4 times and get the same result. Got my chemist wife to do it and she got the same. We left the air gap as instructed to etc.
I can only assume that the API is correct and Salifert way off. My seawater I use is aprox 420 ppm naturally.
Any ideas what I'm doing wrong?
I've since setup my 90 gal with predominantly live rock, coral skeleton, and aragonite sand. My API test kit reads 420 ppm. I recently purchased a salifert bundle and tried the calcium test to compare. For some reason it's coming back with 490 - 500 ppm? I've done the test 4 times and get the same result. Got my chemist wife to do it and she got the same. We left the air gap as instructed to etc.
I can only assume that the API is correct and Salifert way off. My seawater I use is aprox 420 ppm naturally.
Any ideas what I'm doing wrong?