I did a test this morning and got a very faint positive. Then as I threw the test in the bin I looked at the test I did yesterday, and a positive line has appeared but when I did the test yesterday there was nothing.
I have read about evaporation lines, is that it? Though in the test instructions it says, you can keep the test almost indefinitely and the results won't change?!?
I know that I need to retest tomorrow and see, but wondered what this was!