Mixed Reviews On Hydroids - Need To Discover The Truth!

So I was staring at my tank today and noticed this little thing on the glass that looked like a snowflake. Taking a closer look I discovered maybe 10 more but really really really tiny! I did some research and could definitely identify them as hydroids. So my question is; are they harmful or not? I read many reviews but was torn deciding on an answer because some said they are harmful and should just come off in time and others say they are worse than aiptasia and are a bother. Really need help.... and if they are harmful, how can i get rid of them? Thanks, any answers are greatly appreciated.

 

Sounds like Hydroid jellies, often found in newer set ups and harmless.

There are many types of hydroids, and image would help to establish type of hydroid versus aiptasia.

 

+1

As Corailline stated, there are many types of hydroids; hydroid jellies (and some others) are harmless and short-lived. OTOH, there are a few, such as colonial hydroids (looks like clusters of small feather dusters), that have a nasty sting and can over-run your tank.

 

Take a look in our Pictorial Hitchhikers Guide to Your Aquarium

It's easy to use...just scroll down and find your critter for an ID and additional info. There are sections for both motile and sessile hitchhikers, so there are different hydroids in each section, altho it sounds like you have hydroid medusae, which will be in the motile section.