blurry tank

[cf1]

Hi aquarium people,

I started a 75g tank with fresh water with only 6 fishes. After a week the tank look blurry, after changing the water about half of it, the tank look s a bit clearer. I wonder if its the issue wuth the filter. Thought I got the right one for the 75g tank. Would a vavkground help? Or get a better filter?