White spots

[fishtex]

So I need some help playing the guessing game. My wife just told me that a couple of my fish Are developing white spots on their sides. The only ones affected so far are Mono argentus, the tank is a 150, with salinity about 1.006. there are archers monos 2 jade gobies, 2 brackish cats, and a few puffers. There have been no new introductions in the last 4 months. only live food they get are guppies which breed in the sump of same tank. filtration is a sump and 2 eheim 2028s. I dont have water parameters or pics yet. She says it looks like ich but if nothing has been added to tank is that possible?
I am in korea and this tank is at my house in texas so please help if you have any ideas.

 

[crisper]

white spots sound like ich..

 

[fishwhisperer]

iv never heard brackish having ich, if its ich i would slowly go full fresh then if ur ich remains then bump it to full salt SLOWLY, 2 different strands for each type of water, niether can live in the others water type

 

[fishtex]

Is it possible for it to be ich if there has been nothing added to the tank in 3+ months?