Hi all
Just added another addition to my aquarium. A juvenile blue tang
When I baugh it today I inspect the fish in the bag as I do with all my purchases and it looked healthy and full of life but after 1hour in my tank it's coverd in what looks like white spot.
Can it for so quickly?
Do blue tangs get stressed massively when moved?
I will try and upload a photo or video

Hi, Jordan. 

Yes regal tangs are very susceptible to white spot, about the most of any tang.

It's because they're so panicky, and nervous it makes them more stressed than others.

Also, your 90L tank is far too small for any Tang, even a Kole I'd suggest.

They are very cute at that age.

Treating white spot in the tank will kill the corals, so you'll have to set up a quarantine tank, and transfer all the fish to that.

I wouldn't use hypo salinity as it's so small and fragile at that age. Use a medication instead, but that likely won't be suitable for your corals and inverts, so will have to be in a separate tank.

A few treatments will work, cupramine, cuprazin, etc, they'll all probably use copper, so don't get it near your display tank.

NT Labs Marine Anti-Parasite Treatment | Swell UK Ltd

Seachem Cupramine 50ml  Copper Solution Fresh & Salt Water