What are these white Spots ?

[xc700dave]

My goby got these spots a couple days ago. they are about 1/8 in dia. all fish have been in the tank for 6 mos or more
ph 8.1
temp 80
ammo 0
nitrite 0
nitrate 20
cal 420
alk 11
Tank size 150 reef
Thanks for the help.

 

[xc700dave]

another

 

[beth]

Are those just on the fins?

 

[xc700dave]

Yes they are

 

[beth]

Are they always in the same spot? I'm thinking grains of sand. If not, then it could be Lymphocyctis. Take a look at the Diseased Fish Thread and look for the fish with this disease.
What are your water readings and is this fish eating? What are you feeding your fish?