White spot treatment - treat entire tank or isolate?

hello, Unfortunately, one of my fish has white spot disease. I am going to treat the tank with some medication. As the fish is in a community aquarium can I treat the whole tank or should I separate the fish to treat it?
In other words, will the medication affect the other fish that don't have white spot?
Thanks.

 

Do you have a pic of the fish? Make sure that is what it is before treatment. You will want to treat the whole tank for it now unfortunately. What kind of medication is it?

 

Pictures may help to diagnose....if with white spot disease you mean ich, then you have to treat the whole tank as the ich on the fish is just one stage of the ich life cycle.

 

he is hiding right now so can't get a pic but I will try and get one as soon as he comes out.

 

What kind of medication do you have on hand?

 

Also, how big is the tank and what is the stocking?