I did a change not to long after taking the pic and it was a little cloudy if that’s what you was talking about. But when I bought the fish at my local store it, they had about 10 or baby jds and looked just like this oneWelcome to MFK!
As most members have said that is a FH and if he's only 6in he's pretty thick already, a 75 gallon is perfect for a FH as a wet pet and he will have the best personality in there by himself.
I have to ask who told you that was a JD? and how did you buy that fish not knowing that was a FH?
Not trying to be rude here but i would do more homework on fish keeping is the tank cycled?