Tilapia Eye Problem

[Nathan]

I bought a male O. Hornorum a week ago.  He arrived looking very healthy and stayed that way for about three days.  On the fourth day I noticed a membrane from behind his eyes starting to bulge out.  His eyes are not clouding over nor does it appear to be getting worse (unless slowly) and there is no hemorrhaging.  This does not seem to be popeye as his eye has stayed in place but something behind his eye is being pushed out and around his eye.  Other than the eye issue he seems to be in great health eating well, swimming around the tank, and fins are not clamped.

Please help!  I am hoping this is not the beginning stages of streptococcus.  

I have provided pictures.  The whitish ring around his eyes are the "membrane" that are "popping" out.

Water Parameters:

Nitrite: 0

Nitrate: 0

Ammonia: 0

Ph: 8.0

Hardness: 100

Temp: 70 (I lowered the temp in case it might be strep)

I do use untreated well water with a hardness of about 140.