HELP! I woke up this morning and my tank was REALLY CLOUDY! I have had the tank for over 3 months now. One fish is on the verge of dying, as if the water caused him to become stressed out overnight (gills are shredded,color fading, and eyes are near black) What do I do! I did a 75% water change and it helped a little bit, and I added some stuff to clear cloudy water, as well as some stresszyme. Other than that, what do you all reccomend, or what do you think happened in a 24 hour span?