I have 3 large(12-14 inch)GF. Largest is male comet,almost as big regular female, and smaller male. All three have been very healthy and will spawn given half the opportunity. They are in a 150 gal tank. Up till now the smaller male has been the most active and aggresive breeder of the 2 males. Recently he has begun to hang head up in the water in an almost vertical postion. He still feeds normally and does swim around without apparent difficulty. But then he goes back to (hanging). The tank tests out ok, but I cant figure out what his problem is. Last time I saw something like this it was a large fan tail, but that was years ago and that fish was given to me and was never healthy. I have had these guys for over a year with no problems till now. Any ideas?