I can't say thanks too much! So I am watching my Nice LARGE Koran Angel and I thought what you described perfectly on my Angel was the "changing to adult". Was HLLE.
I will find some sponge immediately tommorow and feed him. I think it is stressed a little, i have him in a 90 Gallons. Water is good. but i will test again this weekend. he is my pride and joy! I will take a photo and post later. i feed him hiraki angel, myosis frozen and algea sheet. guess it's not enough and i feed him twice morning then dinner.
his tank mates are 2 clarkii, 2 anenomes, fireshrimp, coral banded shrimp, diamond goby, assorted snails and crabs.
I know i don't do enough maintainence, only carbon pillow change once a month, and 5 gallons. might need to rethink that.
any comments i welcome.thanks again. like i said it has been this way for months. I only hope i can save him now.
Anna& Mike