Acclimation is a big deal for new juvenile clowns. Lfs hold them at low salinity in order to suppress disease then they get quickly raised to tank levels at a home... normally should take three days to acclimate from low salinity holdings. Bag floating stresses them per the disease forum, and running no acclimation steps is also harmful per searchable threads from Jay
Most people run carbon or do a water charge first, so that fish weren't added to cloudy water. That can easily be bacterial blooming from too much cycling feed input.