Help me with my green star polyps

[krazekajin]

I have a 29g reef that has been set up for three years. I have always since the beginning had a gorgeous stand of GSP. They were lush and full and I have been able to frag huge rocks of them (Larger than a softball and almost as big as a volleyball.
However, Lately I have noticed them to be bleaching and slowly receding and thinning out.
My levels are all great.
Am, trites, trates - 0
phophates - 0 or very close to it.
alk - 5.6
calcium - 400
salinity - usually at 1.025
temp is a little high but it has been like that since day one.
The only thing I can think of is that there is xenia near it. Would xenia fight and hurt my GSP?

 

[paintballer768]

Im pretty sure xenia could fight GSP but they would need to be in contact with each other for that to happen. This could be caused also by maybe over exposure to light, maybe you just changed out your lighting recently or your photoperiod may be a bit long and intense for it. Those would be the only things I can think of.

 

[krazekajin]

Well, I am leaning towards some combination of these things.
My MH bulb is a year old so probaly needs replacing. There are two large aptasia that need killing that touch the coral on a corner. I am going to try to direct more flow in that area, maybe the flow has changed.
i am also going to do a lugols dip to kill any creatures that might be harming it.

 

[nycbob]

mh needs to be replaced every 6 months. when u repl them, make sure u put a window screen under them.

 

[krazekajin]

is the window screen to prevent light shock from the new more powerful bulb?

 

[rcoultas]

Originally Posted by KrazeKajin
is the window screen to prevent light shock from the new more powerful bulb?
Yes - that's correct
The aptasia touching it could definitely be a problem as they are stingers