How big is the tank? Three angelfish are a lot to put in any size uncycled tank at the same time. The cloudiness of the water could be from a bacteria bloom. Bacteria blooms are completely normal and benign. The fuzzy slime stuff on the fish is probably a fungus. It could also be Ick if you have white spots that look like white heads. They probably got whatever it is from being stressed out in a non-cycled tank. When you add a lot of fish at one time, diseases are common. Also, angelfish are very sensitive fish and can be very difficult to take care of. I know that they are especially sensitive to pH changes, but are a delicate fish in general.