how many goldfish and what kind? IMO
more than 1 goldie per 10g is too many.
what are "fine" readings? NH3
= 0 and NO3
< 20 are ideal
what kind of filtration do you use? did you replace any filter media recently?
chances are, that the cloudiness is a bacteria bloom and will go away on its own - you likely killed off most of your bacteria population and it will take some time to re-establish itself. You might go through a mini cycle and if so, you will need to do small PWCs frequently to keep ammonia and nitrite readings < 0.5 ppm
edit: did you vacuum the gravel or just use it to replace water? also, how often do you usually replace water and gravel vac?