Rasta zoos turning black!

[Pezking182]

Anyone have a clue to why my Rastas are turning black? All other zoos are doing great.

Parameters
Alk 8.6 (Hanna)
Temp 79
Sg 1.026
Calc 470 (red Sea)
Mag 1450 + ( red Sea - haven'ttested mag in a while)
pH 8 (API)
point of sale .06 (Hanna)
Nitrate 2 ppm (red Sea)

 

[DSC reef]

The colors of zoas can actually get rubbed off. Could be a snail crawling over it. I've accidentally done this fragging or moving a frag. It should regain its color.

 

[zoaplug]

I would give it better light and better flow water change couldn’t hurt either

 

[ironlungzzz]

+1

 

[Beau_B]

Raising from the dead because I have a similar situation. Oxides and Sunny D frags have some black developing. Other varieties (6) in same area are fine...

Any update on what causes this?

 

[zoaprince]

Raising from the dead because I have a similar situation. Oxides and Sunny D frags have some black developing. Other varieties (6) in same area are fine...

Any update on what causes this?

it's likely what @DSC reef said. Have the black spots been the same size or is the spot growing?

 

[ChiCity]

yeah, generally bruising…
but could be expelling zooxanthellae too

 

[Beau_B]

I guess it could be bruising, but they aren’t in a location that gets a lot of traffic and the other colonies around are unharmed.

I can’t be sure if it’s spreading yet. I’ve had them for months but only recently had a couple turn black.