Before adding the fish, do a full panel test ( pH, ammonia, nitrite, nitrate, general hardness, phosphate) of the water to make sure nothing is out of whack. As for the purigen, look and see that it hasn't turned brown. If it is, it's saturated with organics and needs to be recharged ( as per the directions). If it IS brown, it would make sense that the tank had a lot of organic waste in it which is why you are seeing brown everywhere. That would be a sign your filtering system in not adequate for your fish load.

If that isn't the case, I'd be on ammonia& nitirite watch after adding back your fish since that haze is typical of an overcleaned filter / new tank lacking nitrifying microbes. .