Silver dollar sick?

[ZWICK3R]

Hey guys, I'm new to keeping silver dollar fish and really to keeping fish in general (had a tank a few years back) anyways I got 2 silver dollar fish from the local store yesterday and when I got them home I relised one of them has a fairly large white spot on one of his fins (not the actual dorsal fin but the smaller one behind it) the other silver dollar dosnt have this. Besides that he seems okay he acts just like the other one dosnt look stressed or anything and he swims around perfectly normal, is this a sign he might be getting sick? Or could it just be the way he's coloured? Thanks

 

[fishlover22346]

If you can get a picture that would be helpful, but I do know that silver dollars are hard to get a pic of. It could be icy or fungus, but I would need a picture to see for sure. What is your tank size and water parimeters? and if you can’t test the water quality then is there anything else in the tank with them?

 

[ZWICK3R]

I'll try to a picture later I'm out rn but my ph is about 7-7.5 no nitrite lvls hardness is about a 90 I believe and he's in with an Australian blue lobster, I got the silver dollar from the pet store introduced him to the tank and then about an hour later I noticed the white spot on his fin

 

[fishlover22346]

btwI meant ich not icy lol, but the water parimeters sound good, what’s the tank size? also, can you describe the white spot a little better? because It could be anything from ich to a scrape or something like that.