What is going on with my grouper?

[Chappy8]

I have had my miniatus grouper for 2 weeks now and when I got him he was bright orange with blue spots.bright orangeAbout a week ago he started to become very dark toward his tail and i think his front is becoming darker also. The color that is taking over is like blackish and a little spotty but you can still see the orange. We have a huma huma trigger in there and they don't fight at all. Nothing has changed with the trigger's color however. We feed them sivlersides and krill once a day with zoe. They both devore it and are very active during the day. Can you please tell me what this blackness is if anything? Thanks for all your time and replies. Corey

 

[jmeader]

Generally when a grouper darkens it means something is stressing it. Check all your water parameters. Then look closely for any sign of ich. Also check the breathing rate.