What are these tiny things?

[tdenham735]

Hi Everyone,

I've noticed recently some very small things growing in my tank and seem to be spreading rapidly, including to the glass. The average size seems to be about 1/2 mm, but some a little smaller and larger.

Anyone have an idea what these things could be? Some kind of worms? Are they bad?

Thanks...

My tank is parameters seem ok, Nitrates barely detectable, Calcium about 460 and DKH about 10 at the moment. No detectable phosphates, but not sure how well the test kits work on phosphates.

Tank is about 65 gallons and have a couple of corals, two clown fish and a few peppermint shrimp.

Here's a photo of the critters?

 

[Aquarian]

They are Spirorbis spp. Spirorbid worms they are harmless filter feeders and will come and go. They are good to have

 

[tdenham735]

Thanks for the quick reply. im glad they are harmless...whew!