Odd Zoa Issue

[fishnoob~noclue]

Hi All,

I've had some issues recently with a certain type of zoa growing in my red sea 250.

About 6 months ago my larger zoas frags and colonies previously growing fine suddenly stopped extending their polyps and in some cases detaching. Whilst my smaller polyped zoas are growing fine.

My parameters are:

Alk 8.4
Cal 440
Mag 1500
P04 0.06
Phosphorus 21ppb
Nitrate 25
1.0265 sg

I have attached photos for reference.

I've given one weak attempt at iodine dipping to not much result.

Any help would be appreciated.

Thanks

 

[Tahoe61]

It looks like some colonies are reaching for light?
Have you checked for the usual suspects?
Nudibrach
Sea Spiders (they are hard to see)
Asterina
Sundial Snails

 

[fishnoob~noclue]

Thanks for the response, I've tried looking for them but can't see any clear evidence of any of the pests.

Do you have any tips or tricks to find and identify them?

Thanks

 

[Tahoe61]

There are Asterina Stars in your tank?
Looking at night with a flash light is the ideal time to see pest out and about.
Typically I find Sea Spiders when dipping frags. Personally I like a hydrogen peroxid dilution dip.

What lighting are you using?

 

[fishnoob~noclue]

There are Asterina Stars in your tank?
Looking at night with a flash light is the ideal time to see pest out and about.
Typically I find Sea Spiders when dipping frags. Personally I like a hydrogen peroxid dilution dip.

What lighting are you using?

Thanks for the suggestion, but I've been searching for last couple of nights but I can't see any pests.

I have previously fragged the colony, is it possible they got an infection during that process?

Other than that I'm pretty stumped on why they're upset.

Thanks