Can someone please help my figure out what this is and how to fix it. Thanks A little about the tank. 90G FOLR stock list
1 clownfish
2 small blue damsels
1 small 3 strip damsel
1 lunar wrasse
1 yellow tang
1 checkerboard wrasse
1 snowflake eel
3 feather dusters
1 pink cucumber
1 orange tree sponge