There's 3 males in the 10 gallon. I'll correct myself and say that it wasn't really green like it shows .25 on the chart. It just wasn't dark yellow.. more of a light yellow. The latest fish was added about 3 weeks ago, and I always do a 50 % water change.
Be sure and clean those test tubes and rinse them out alot ! I had a couple of high readings cause I didnt rinse them enough or at least I think thats what happened cause when I cleaned and rinsed them out again and retested it was fine.