Perfect circles in my algae?

[Kelstofer]

So, over the past week or so I’ve started noticing these dots showing up in my algae and I have no idea what’s causing them, could use some helo

In the tank I have;
2 Clownfish
1 Royal Gramma
1 Fireshrimp
1 Watchamn Goby
1 snail

The newest additions to the tank are the watchman goby and aircraft of gsp

What could be causing these? They’re like perfect circles

 

[sfin52]

Snail is my guess

 

[sfin52]

Beautiful scape

 

[The_Paradox]

Snails and urchins tend to leave circular or oval feeding marks.

 

[Kelstofer]

Snail is my guess

He leaves a clear trail wherever he goes, these are perfect circles

 

[Kelstofer]

Snails and urchins tend to leave circular or oval feeding marks.

The snails been there for a bit, and this is a new development. I also don’t have an urchin

 

[The_Paradox]

The snails been there for a bit, and this is a new development. I also don’t have an urchin

Fine.

 

[shakacuz]

wild guess but could be bacteria and coralline algae competing for space.

other guess is perhaps the clowns have hovered over the PVC and rubbed off some algae from it?

last guess would be the snail. i’ve seen some snails take a break then go back to town after sliding around the tank a bit

 

[RabidDragon]

The circles are varying in size and location, including in the sandbed.... its some microfauna competing for real estate.
Watch them over a few days, do they grown in diameter?

 

[Patx]

Look like a petri dish culture.
Just saying.