Hi there, abit more info on your tank would help to find the cause of the problem. How big is your tank. What have you got in there. Any new addition to the tank apart from the filter. Have you remove the U/G filter ?Did you disturbed the gravel? What is the parameter of your water(PH,Nitrite, Nitrate, Amonia) etc..
It might be a bacterial bloom causing the water to go cloudy. I would stop adding stress zyme everyday. Do a big water change and add something like B Clear to clear up the water. HTH
cheers,
ron