Are you using an API test kit? What hardness are you testing, GH or KH?
It's the Aquarium Pharmaceuticals gh and kh test kit. Thanks Sherry
OK, thought so. I found a little trick with them and certain types of water samples. When starting the test(s) with one drop at a time, keep an eye on the water level line. It is usually a convex miniscus(sp?). Veiw it from the side as well as the top looking down. Sometimes the color change actually does occur, just in the miniscus. Also, dont cheat, only one drop at a time. Rinse test tubes good with tap water after use, then rinse once or twice with tank water (or water sample to be tested). The outcome may change. I thought I had the hardest water on the face of the earth for years. Pure liquid magnessium and calcium. Then I noticed, by accident, the miniscus had changed color after only one drop, but never completely changed the water color. This was confirmed by a water analisys by a lab on my private well water. I told someone else of this about a year or 2 ago, and they got the same result as I did after realizing the "spot" to look. This was for the GH test. If you have high calcium carbonates in your water with the KH test, it will turn a dark (blue I think is the first color) color at first. Then it may only go clear instead of the next color. I can't remember the colors, My tanks have been packed since September last year, except for 1. I didn't really test KH too much in that for a while because I had no concerns. Wont set up the aquariums until the new house is done being built. I am in an apartment for the next 2 1/2 months until then.
Thanks will try that. Good to know, lol. Best Sherry