GSP Weirdness help

[bsfmaximus]

My gsp has been opening less and less over the past three days. Today it seems to be almost completely retracted. Meanwhile it's purple mat seems to be spreading. Does growth coincide with polyp retraction? Is there another common reason that it would be retracted all of the sudden? All other corals in my tank seem great, levels are good.

Related here, as seen in the picture, what is this large, lone "tube" coming off of my gsp? Haven't seen anything like that on a gsp before.

 

[ihavecrabs]

Could it have been physically bothered? i.e. hermit running over it?

Sometime mine closes up on one side while the other is fully open. It typically opens back up within a few hours though. In the past before I was closely monitoring and managing by parameters, it would stay closed for days at a time. It is a very hardy coral but swings in parameters could also cause this behaviour.

 

[bsfmaximus]

No to the smothering. In fact I haven't seen hermits near recently. In the past when bothered by hermits or me, it is fairly quick to open back up. Parameters are consistent. Any idea on that tube like structure coming off off the middle of the mat?

 

[ihavecrabs]

I don't see what you mean by tube like structure unfortunately.

Is it directly under intense light?

 

[bsfmaximus]

 

[bsfmaximus]

 

[reefndude]

Looks to be growth. Mine grows tube like structures all over

 

[twilliard]

I use GSP's for water indicators.
Have you done anything to change the chemistry of the water ?
No3
Po4
ALK
And so on?

 

[bsfmaximus]

Water chemistry looks normal for my tank. I keep it consistent and test every few days or so. Could my toadstool be culprit via chemical warfare? They are a few inches apart. The toadstool is also a few inches from a colony of zoas that are doing fine.

 

[bsfmaximus]

Nitrite 0
Nitrate 10
Phosphate .25
Ph 8.2
Calcium 400