choc. chip starfish needs help

[benguck]

I've had my choc. chip starfish for over month doing great and now over the last week one of his arms has slowly been deteriating and leaving small, white spheres (they look like small, white beads) on the substrate where he has been hanging out. All levels and water quality is qood. Anybody have an idea of what's going on? Thanks :help:

 

[ophiura]

Unfortunately, we can't really tell anything (other than it is in trouble) without knowing SPECIFIC water parameters. Please give us:
ammonia
nitrite
nitrate
pH
alkalinity
specific gravity
recent water changes (how big)
age of tank
inhabitants
what and how often you feed
how long did you acclimate
Can you get a picture?
The time frame and description seems characteristic of acclimation shock. It is important to understand that what is "good" for fish only systems may be fatal to these sorts of animals. Knowing specifics is crucial.

 

[benguck]

tank is 4 months old
ammonia 0
nitrite 0
nitrate 5
pH 8.3
sp.gr 1.024
did a 20% water change a week ago right after I started noticing his condition
tank mates include Hippo tang, coral banded shrimp, cleaner shrimp
55gallon tank
enclosing some pictures (the healthy pic is what he looked like when I first got him (month ago
I cant' get pictures to upload, can I email them to you?

 

[ophiura]

You can, I'll upload them.
ophiuroid@"no_spam"gmail.com
Obviously remove the "no_spam" part

How do you measure your specific gravity...with a refractometer or a hydrometer?