Thanks, that is a lot to consider.
Could be that there is too much flow. I did increase the flow to them in an effort to get them to come out, but they are definitely coming out more when the powerhead is off.
It has been in the tank for maybe a month? I am not sure.
I don't know my phosphates unfortunately. I should maybe be checking them, but I have not so far.
They may be bothered by the frequent back and forth passing of my clarkii clownfish. They have never showing any interest in the GSP, but they do live behind the rock that the GSP is on. That means there is a lot of traffic around the rock.
The lights are not on a timer, but I would say that they are still pretty consistent (+/- 15 minutes).
The tank has been up for 5 months.
thoughts