Corals are coming off their skeleton and I don’t know why.

[ILMX20]

Two of my happiest corals -that I’ve had for almost a year now- have started coming off their skeleton. The coral itself isn’t actually dead, it’s just kinda half hanging off. I haven’t changed anything at all about my routine. Still weekly clean ups, I’ve dipped the corals to make sure there were no pests, the water parameters are almost completely fine (my phosphates are a bit high, but they ‘re going down with the water changes). It’s really sad because I love these corals and it happened within two days of each other and before that they looked perfectly fine. Anyone have some advice as to why it might be happening. I’ve attached two pics of the corals, a torch and an elegance. Is there any way I can keep them alive? I’ve never had this problem before.
Thank you!

(ah, also, I know the rocks are super green, but that happened a long time ago, and I’ve tried treating it but it’s not going away.It doesn’t really bother me and it’s not something I’m concerned about.)

 

[Anubisxii]

#1 question is what are your parameters at? Anyone who is going to try and help will want to know.

I'm going on a stretch here but it could be polyp bail out. Meaning the corals not happy and in the process of bailing the polyps so they can find a better area. Do you have other coral and if so how are they doing?

 

[ILMX20]

#1 question is what are your parameters at? Anyone who is going to try and help will want to know.

I'm going on a stretch here but it could be polyp bail out. Meaning the corals not happy and in the process of bailing the polyps so they can find a better area. Do you have other coral and if so how are they doing?

Ammonia: 0
Nitrites: 0
Nitrates: 10 (it is water change day today,)
Ph: 8.2
Salinity: 1.025

my other corals seem fine. I have a Goni, a Kenya tree, frogspawn, and an anemone, who all seem the same as usual.

 

[Anubisxii]

I'll give you a bump to see if anyone else can give their .2 cents

 

[James M]

Do you know any other parameters like Alk, calc, po4 ?

 

[ILMX20]

Do you know any other parameters like Alk, calc, po4 ?

Unfortunately I don’t. I took a water sample to my Lfs, and he tested it for me. He said my phosphates were a bit high but didn’t give me the actual result.

 

[MONTANTK]

Could be low magnesium. That is the element responsible for holding corals to their skeletons (among other things I’m sure). Could also be polyp bailout as previously mentioned. It’s very important to test your alk, calcium and magnesium when dealing with stony corals.

 

[James M]

Unfortunately I don’t. I took a water sample to my Lfs, and he tested it for me. He said my phosphates were a bit high but didn’t give me the actual result.

I would look into getting a test kit...Avoid the API ones as they are inaccurate.

 

[Tired]

Your rocks are supposed to be green. They're going to get covered in assorted algaes, and until/unless coraline algae colonizes most of the space, you'll see green. Don't try to get rid of it, you'll just open up space for peskier algaes to grow.

Is it possible something toxic could have gotten into the tank?