How big are your goldies? A 10 gal
tank is way too small for 5 goldfish. Goldfish require 10 gals per fish. Test your ph out of the tap and see what the readings are. Are you adding any chemicals to the tank? The cloudiness is either a natural bacterial bloom that will go away on it's own or a result over a high bioload and low filtration. I have a 33 gal
goldie tank with a high bioload and I run 2 filters rated for 70 gals each. 600 gph
overturn. Until I had that kind of filtration the water was always slightly cloudy.
As for the goldie floating upside down, goldfish are prone to swim bladder issues. To help this fish first do a 50% water change. Then you will have to decide whether to get another tank or return some of the goldies to the lfs
. As for your parameters, what are the readings exactly for ammonia, nitrite and nitrate? You can add some epsom salt to your tank to help the upside down goldfish and cut back on feedings. Epsom salt, 1/8 tsp per 10 gals. Also try feeding some frozen peas, blanch and peel and make into bite size. Good luck.