Looking for help

[ThorEffex]

So when I got home about a week ago there was a dead and dieing coral in my tank and I don't know why. So I was hoping some one might have some ideas. So here is 2 pictures of the coral death in progress, I did frag the coral and all 5 pieces are doing well.
2 days ago

Today

And now another corals starting

I do use rodi water 0tds if my meter is good. Only thing new was I added 2 emerald crabs to eat bubble algae. Which made their home close to the corals affected.

I did test my water today it's 1.026, ca 380, alk 9.1 mg 1330

 

[Wazzel]

Hard to say from the information provided. You Ca is a bit low, but should have not caused that.

Look for
1. Pest
2. Anything that changed or spiked right before it happened.

 

[ThorEffex]

Well I don't see any red bugs or signs of flat worms. The area is kinda low flow I guess, I did clean the power heads about a week ago. I have not changes any thing like overhead positions for about 5 months so I'm not sure why it would have a problem now. I did baste the spot and a lot of detritus was in and around that area. Phosphates and nitrates are undetectable.

 

[PaleHorse]

http://www.reefcentral.com/forums/showthread.php?t=2430841

Alk swing??

Like wazzle said Cal is a bit low. Follow the format in the link so we can help more.

 

[swhobbie1]

Some people have reported that they have observed emerald crabs eating their coral. That is why I won't keep crabs in my tank - i don't trust they won't try to eat some corals now/then.

 

[ThorEffex]

Yeah I pulled one out today and now I see the other one working the bare spots on the coral. I think they have to go the bubble algae is going to have to be taken out by other means I think

 

[PaleHorse]

Some people have reported that they have observed emerald crabs eating their coral. That is why I won't keep crabs in my tank - i don't trust they won't try to eat some corals now/then.

Yeah I pulled one out today and now I see the other one working the bare spots on the coral. I think they have to go the bubble algae is going to have to be taken out by other means I think

Do not put a emerald crab in your tank, they are known to eat sps

 

[ThorEffex]

Yeah I almost caught the 2nd one last night but they are fast little buggers

 

[swk]

My emeralds were caught demolishing a few acro colonies before I finally caught on. I kept telling myself "oh I'm tripping. They're probably just cleaning some algae"

Fwiw - it always seemed to be the males that did the most damage. The only emerald I have left is a female with one claw. All the rest went bye bye