maybe fungus?

[mos90]

on my 6" male ray, right on the beginning of his stinger it looks like a cottony white ball . im thinknig it is some sort of fungus.

what meds should i use. or just salt.

tank not finished cycling so i need to use something that wont harm the process.

 

[mos90]

ive been doing 50% water changes every other day.

looks like pimafix might work.