When I turned the tank light on in my 25 gallon platy breeder tank, the water was all cloudy. After testing, my readings were all normal except the ammonia has jumped up to .25ppm. I am getting ready to do a 4 gallon water change on it but, what could be causing it to just cloud up all of a sudden? I dont think its BB because the tank has been cycled for weeks. I dont over feed, my platy's get pellets every other day and the tank is vac'd 2 times a week.