I have a question about the Aquarium Co-Op ammonia test strips that I am embarrassed to ask. I know it states in the directions that the test strip should be read immediately, but it seems the color will change after a few seconds of being out of the water. Should I consider the reading I have of .5 ppm right out of the water as correct, or the reading 5 seconds later of 1 ppm? Thanks in advance for any replies.