White dots on tank glass

[charlie7073]

Any help identifying these white spots that seem to be swirls up close and have sharp spikes?

 

[ludnix]

They are called spirobid worms and are a type of tiny sessile filter feeding featherduster. They are not an issue and can be easily cleaned off with a scraper or equipment can be cleaned with an acidic bath like citric acid or vinegar.

 

[charlie7073]

They are called spirobid worms and are a type of tiny sessile filter feeding featherduster. They are not an issue and can be easily cleaned off with a scraper or equipment can be cleaned with an acidic bath like citric acid or vinegar.

Thank you