My Jap. quail eggs are a day late hatching so far, I have tried candling them but not with much success because they are so dark. I was on YouTube earlier and thought I would check to see if I was actually doing it right when I came across a lady water testing hers. I watched very carefully (three times) and thought I would give it a go. IT WORKS!!!! 10 of my 12 eggs started wiggling around. I used purified warm water and only had them out for a few seconds before getting them back in the warm. I was getting so worried because they were overdue and now I know they are viable. I am so happy, now just need to get them successfully hatched and brooded. Fingers crossed everybody