I have a 10 gallon tank that has been running since September. I finally got the tank through the cycling process around November. All has been well until about a week ago then my water started to get cloudy. It was about time for my weekly water change so I did it hoping this will help. The water still looks cloudy. Levels are as follows: Nitrate 20, Nitrite 0, Amm 0, PH 6.8. I have a hagan co2 system that I got for Christmas that has backed up a few times into the tank making it cloudy. I have always caught this early and with water changes it goes away. I am monitoring the co2 system and I have not seen it backing up into my tank. So do you think I am missing the system backing sometimes or could it be something else?