I've been having issues getting my zoathids to spread. I've had this tank in this configuration for about a year and a half now. About 4-5 months ago I almost killed off these buttons due to the lights being old. So I went ahead and bought some new T5H0 Purple and white bulbs and they seemed to be making a recovery. A new coral actually grew up out of the same live rock piece that I bought with them on it. I have them up at the highest point in the tank tucked into a rock because my urchin acts like a bulldozer to anything that isn't secure. About a month ago I noticed that growth had stopped and this week many of them have been closing up.
I can't figure out why these guys aren't growing please help.
Two side hanging filters and a pump for water flow.
Lights T5HO purple and white bulbs ~5 months old
Water temp 78-9
Sunflower (Yellow Flowerpot) coral at the bottom of the tank