Does any one know what these perfect circles are?

[kingranch2003]

 

[leob201187]

Urchins do it tangs can do it. Any algae eating fish can do it

That’s true

 

[jaykinch]

Hey is it new rock from the shop wondering if something has been stacked up on it, or some chemical dropped on it

 

[themcnertney]

No

I guess we have different ideas of what the circles are in your photo.

 

[leob201187]

I guess we have different ideas of what the circles are in your photo.

Anything would help

 

[leob201187]

Hey is it new rock from the shop wondering if something has been stacked up on it, or some chemical dropped on it

Yes new rock but it was washed before add to the tank. The whole thing was covered in green algae just like the areas around it..

 

[BubblesandSqueak]

Yes new rock but it was washed before add to the tank. The whole thing was covered in green algae just like the areas around it..

finger prints? oil from fingers when you placed them?

 

[Janet Belanger]

Wondering if your "algae" is actually something like diatoms or dinos, and those rings are die-off.

 

[leob201187]

Wondering if your "algae" is actually something like diatoms or dinos, and those rings are die-off.

That is a possibility but not sure. This the first time I experienced this

 

[leob201187]

finger prints? oil from fingers when you placed them?

No I washed my hands and rinsed everything

 

[19Mateo83]

Just out of curiosity , what is the volume of this tank with rings?

 

[leob201187]

Just out of curiosity , what is the volume of this tank with rings?

150 gallons total including sump

 

[Clarkjw2002]

Have you looked at the tank in the middle of the night with a blue flashlight?

I have had worms in the past that would stretch out and clean the algae and detritus around a central hiding spot. upon shining with a light they'd retract into their refuge spot. This could explain the circle--a circumference around a central refuge spot.

My guess is you moved something with the 20lbs of sand from your previous system. When I've had them they always came with real, mature, live rock and their feeding patterns were almost unnoticeable. On new rock they might just be picking clean because of a lack of a mature bio load. If I remember correctly, they were some type of oligochaete, not polychaete, worm.

In any case, I would not worry about it.