I should have asked this from the beginning, how's your system doing besides the chaeto? Corals, fish, appearance, pests?
Fish are fine but corals are not happy at all and receding. Even the GSP and Xenia are not happy. I've started up weekly 20% water changes to keep Nitrates down.
For fish I have 2 maroon clowns, 6 line wrasse, yellow watchman goby, diamond watchman goby and a scopas tang. all fish are very small no more than 3" long. The tank is about 40 gallons total water volume