Purple Encrusting Monti SICK???...

[klaeq]

I go this purple encrusting monti about 2 weeks ago. The first pic is what he looked like for the first week and a half. You cant really see, but he is a nice deep purple color. He was doing good for almost 2 weeks, and I had to go out of town for 3 days. The next 3 are what he looked like when I came back from a 3 day business trip. My roommate fed my tank per my instructions, and I took measurements before I left and when I came back. Here is what I am at:
Temp: 81
Salinity: 1.025
PH: 8.2
Alk: 1.7-2.8
dKH: 8.3
Calcium: >450
Ammonia: 0
Nitrite: 0
Nitrate: 0
I'm not sure what is going on. Can someone please tell me if I lost this or not? He is turning white, and has some white spots with little feather looking things growing on him. I no longer have a QT because it cracked and I haven't had the time to get a new one. Thanks for your help guys.

 

[ifirefight]

OK ,your readings for ALK and DKH are pretty far apart...1.78-2.80 ...is a big spread...dKh of 8.3 is fine... Pick a measurement . 1.78 would be 5.0 dKh and 2.80 would be about 8.0 dKh...

 

[klaeq]

Sorry, the 1.7-2.8 was using the redsea test kit. I usually dont use those. The readings are in 'ranges' and not very accurate. The 8.3dKH reading was from my Salifert test kit. I was typing too fast to realize i put both measurements down. Sorry. Do you know what those white spots on my monti are?