What Is This

[Volsman85]

This hopefully is nothing but it like appeared overnight. What is this white stuff and is it a problem?

 

[JGT]

Looks like your coralline algae is bleaching. Any recent changes?

 

[Marlin Spikes]

Sea urchin is hungry.

 

[Volsman85]

Looks like your coralline algae is bleaching. Any recent changes?

No changes. Coralline algae?

 

[ShepherdReefer]

Maybe that is the path of the urchin eating the algae.

 

[Auquanut]

It does look like clean rock left behind after urchin has been grazing. How long have you had the urchin?

 

[Gobi-Wan]

No changes. Coralline algae?

Purple plated growth across your rocks is coralline algae, it’s desirable- a sign of good water quality and prevents uglier algae from taking up the surface space on your rocks. Sea urchins like to munch it though.
What livestock do you have in the tank?

 

[JGT]

It does look like clean rock left behind after urchin has been grazing. How long have you had the urchin?

Yes , just noticed the urchin lurking in the background. Could be your culprit.

 

[Volsman85]

Purple plated growth across your rocks is coralline algae, it’s desirable- a sign of good water quality and prevents uglier algae from taking up the surface space on your rocks. Sea urchins like to munch it though.
What livestock do you have in the tank?

Pencil urchin, 4 peppermint shrimp, 1 fire shrimp, 2 clowns, 2 engineer gobis and one fire tail Gobi, his companion didn't make it and several crabs and snails and bristle worms

 

[Volsman85]

Yes , just noticed the urchin lurking in the background. Could be your culprit.

Month or 2. He's grown 40% at least

 

[Volsman85]

Looks like your coralline algae is bleaching. Any recent changes?

Nope

 

[Gobi-Wan]

I don’t mean to sound silly but... could it just be sand deposited by one of your gobies?