Review on Copper Test Kit: Accurate 90-Test Aquarium Water Testing with API by Susan Cox

Added to my order to get free shipping. I have most of the other API test kits so thought I'd get this to check the copper values for the invert and help with the build. As simple as most other API tests, but there's a problem: it's hard to read at lower levels. The first color is so light beige that it can be confused with the darkening of the test tube simply by placing it on the test card, and the instructions state that ANY change is considered a positive first stage result. It would be nice if API made a small, battery-powered LED test tube rack that you could pop test tubes in and check color anywhere without worrying about shadows on maps or lighting conditions making colors look different. I'm sure you could create such a product, but it would be nice if the API already created it.