Grey covering on montipora

[Paul J]

Some advice please. One of my montipora has a grey covering over it. I removed the main body of the monti but its the growth that has spread over the rock that is greying and the monti still seems to be growing with the grey still on top! There is slight sign of this happening to another monti and to my Scholl coral.
Water and lighting are within limits. No extra corals added for several weeks now. I did increase the sand bed to 1 inche.
No change in the foods used or amounts given. Salt used for water change was Salinity. Which is new to me! H'mm is this it? I started using Phosaban to try and drop Phosphate. below 0.03 a week ago.

I don't see any bugs etc
Running carbon and Purigen in a canister.
Tank running for approx 2 years.
100 litre tank
31 corals, all hard
8 fish
2 sea uchins
11 snails
I doze Fusion 1 and 2 by dozing units which is done each day.
I will be changing 20 litre today which a different salt mix
Any ideas, as soon as possible please.
Thank
Paul

 

[Humblefish]

Can you post a pic?

 

[Paul J]

Can you post a pic?

Thanks for getting back to me

The whiter parts are the grey areas - sorry but not good pictures
Please let me know that you got these pictures. The small coral at the top of the picture was not there until today needs to be moved again.

 

[Paul J]

Can you post a pic?

Sorry the Acans should not have been sent.

 

[Humblefish]

Sorry the Acans should not have been sent.

Let's call in #reefsquad to have a look as well once you get the correct pics posted

 

[Paul J]

Let's call in #reefsquad to have a look as well once you get the correct pics posted

Please see attached pictures P1 and P2

 

[DSC reef]

I see bubble algae and skeleton. Possibly birds nest or digitata? The purple montis look fine.

 

[Humblefish]

Have you tested alkalinity, calcium, magnesium lately?

 

[Paul J]

Alk, Mag, Cal, all test good. Just got my Trition results, no issues with these. I have high Selenium this seems to be a common issue however looking into this and also high Lithium again this seems to be common practise. I have low Iodine and low Bromine. A change of salt mix I think would be in order to help reduce Lithium and Selenium.

 

[kireek]

Hmm.The birds nest looking coral may be getting stung by something.Then again,it could be a chemistry issue or a parasite like spiders.These can be almost invisible to see without a dip.
The Montipora look okay from a distance.I would recommend removing them and looking underneath for nudibranchs.Do this while giving them a nice dip help dislodge anything that would be hiding.Coral parasites are tiny and difficult to see without a close inspection.
It is also a possibility that your urchins are damaging the surfaces as they move along.

 

[Paul J]

Hmm.The birds nest looking coral may be getting stung by something.Then again,it could be a chemistry issue or a parasite like spiders.These can be almost invisible to see without a dip.
The Montipora look okay from a distance.I would recommend removing them and looking underneath for nudibranchs.Do this while giving them a nice dip help dislodge anything that would be hiding.Coral parasites are tiny and difficult to see without a close inspection.
It is also a possibility that your urchins are damaging the surfaces as they move along.

Have you tested alkalinity, calcium, magnesium lately?

Alk, Mag, Cal, all test good. Just got my Trition results, no issues with these. I have high Selenium this seems to be a common issue however looking into this and also high Lithium again this seems to be common practise. I have low Iodine and low Bromine. A change of salt mix I think would be in order to help reduce Lithium and Selenium.

Thanks for the reply. This is a weird one as the monti still spreads over the rock. Cant get it out (well I could but taking the whole rock out is a no/no at this time. If its bugs etc, then maybe I will have too.