tecwzrd said:
Kurt_Nelson said:
I use the AP test for calcium also
How do you like the AP CA test? I've used both the red sea and Salifert test kits and they both work fairly well but cost 2-3 times as much. I have used AP for the basic tests for 15+ years and have always been happy but until this year wasn't even aware they sold a test kit for CA.
AP test kits seem to be the easiest thing for me to find in local fish stores, and as you noted, a lot cheaper than the "better" ones. I liked the ease of use of the basic AP tests, so I bought their Ca test when I needed to start testing for it. I don't have anything to compare it against, but I'll buy it again. 10 drops of bottle 1, shake, then start dropping bottle 2 and count your drops - 20ppm per drop.
Only complaint is that the color change from pinkish to blue isn't very dramatic. You get a purple phase one drop before "true" blue, but their "blue" takes some getting used to. Like most tests, once you know what color you're looking for, it's no problem. For that reason, I've started doing my tests in the same room under the same lights all the time. Colors under 240W of incandescent look a lot different than 240W of flourescent.
Back to the original poster... this may seem dumb, but have you checked your electronic pH meter against a cheapo liquid drop test like AP? If it was me, I'd want a "second opinion" before trusting the results of something that can go in and out of calibration at the drop of a hat. Granted, you can be more accurate with an electronic, but the "compare the color" tests are pretty repeatable and consistent.
