Strange problem with acropora

[icliao]

One of my friend's 400GL SPS coral tank has some problem recently.

Around 40% acropora suddenly stop extending the polyps and begin to RTN.

His tank has been up for 1 1/2 years and no significant change in water parameter. (Using Ca-reactor and Kak reactor)

According to him "suddenly the next day" many of the corals never extend its polyps anymore.

All the newly added corals and those uneffected (from the doom day) show no problem and extend it's polyps normally.

Has anyone experienced the same?

Personally it never happen to me so I don't know what to say.

 

[jer77]

Sounds to me like something shocked them, two things that come to mind are temp and light.

 

[icliao]

<a href=showthread.php?s=&postid=7388748#post7388748 target=_blank>Originally posted</a> by jer77
Sounds to me like something shocked them, two things that come to mind are temp and light.

I thought so. There were no lighting change but the temperature did elevated to almost 30 degree C for a day or 2.

After he did water change, adding carbon and correct the temperature those corals still never recover.