Coral disease?

[Hannahhh]

Can anyone help me figure out what is going on with this coral? A similar thing slowly spread through a green encrusting coral I have in the last month or two. I haven’t added anything new in ages and there aren’t any changes in water parameters.

 

[Chris.Reef]

Seems like it’s shaded out. I assume you tested your water parameters?

 

[Hannahhh]

Seems like it’s shaded out. I assume you tested your water parameters?

I’ll be honest I don’t test them too often, I just do water changes and monitor salinity. I’ve done that for years and had no issues with this coral.

 

[Hannahhh]

Seems like it’s shaded out. I assume you tested your water parameters?

Why would shade suddenly be a problem if it grew down there? I could try cutting back the leather if you think that might help

 

[Chris.Reef]

Why would shade suddenly be a problem if it grew down there? I could try cutting back the leather if you think that might help

From the picture it looks like the top is doing fine but the bottom is what’s receding. Looks like there are some other corals close to it which could be causing trouble.

 

[SteveDola]

Going to be guessing without actual measurements of alk, calc, mg, po4, nitrate.
could be flow or lack there of, could be the leather coral killing it, could be lack of light, could be low magnesium or some other level.

 

[Edward]

Going to be guessing without actual measurements of alk, calc, mg, po4, nitrate.
could be flow or lack there of, could be the leather coral killing it, could be lack of light, could be low magnesium or some other level.

I agree with this completely.

I’d definitely check those alk levels