Are these pest anemones?

[TerenceMcKenna]

My 20g long has been running for 7 months and I have these clear anemones with short hairlike white tentacles that are growing in the back glass and all over the live rock. They are very small, the size of a small shirt button, maybe smaller. I tried removing them by hand when there were only a few and now they are all over the tank. Should I be worried about these?

[SaltyBuddha]

Hard to see. Looks like feather dusters maybe? 

[ajmckay]

Hard to tell but I'm guessing hydroids of some kind.  Google colonial hydroids.

[mndfreeze]

If they are clear but have round balls at the end of their tentacles then they are ball anemones, which are safe and cool.  They usually don't open up in full light and prefer darker spots or when the lights go out.  

 

I can't tell from your picture though.  I would definitely look up pictures of ball anemones as well as colonial hydroids, feather dusters, and other hydroids in general.

[Oldsalt01]

Unfortunately, they don't look like ball 'nems or feather dusters to me. I'm also thinking colonial hydroids, but it's rather hard to tell from the pic. I enlarged it and it looks like there are small "heads" at the ends of the stalks, which are fairly typical for hydroids.

[MarcArgo]

It is not so clear.

[Trish]

The first pic looks like the same thing I have in my tank. I am thinking it is pineapple' sponges. I am told they are (harmless filter feeders).  Please do not take my work for it. Google Pineapple Sponge and see if it is familiar.

[A Little Blue]

No worries, they’re harmless. 

[TerenceMcKenna]

Thank you for all the replies. I managed to take some better pics of the creatures. They have a jellylike body and short white hairs or "tentacles". They don't seem to sting the corals or affect them in any way.

[mndfreeze]

I'm going to have to echo that they are probably sponges, most likely pineapple sponges that are just really small and hard to tell so far.  

[A Little Blue]

4 hours ago, TerenceMcKenna said:

Thank you for all the replies. I managed to take some better pics of the creatures. They have a jellylike body and short white hairs or "tentacles". They don't seem to sting the corals or affect them in any way.

Second picture concerns me a bit. Can you get a better shot of it? 

[mndfreeze]

Should also check the tank in the middle of the night when all the lights are out, then turn them on and quickly get some shots before things close up.  Or use a flashlight while shooting a pic.  There are quite a few hitchhikers that expand to feed at night and close up during the day, like strawberry / ball tipped anemones for example.  

[MarcArgo]

These are considered as pests in the marine aquarium body. There are accidentally imported as hitchhikers on live rock or on the base of corals. If you find Aiptasia in your aquarium, you will want to take steps immediately to keep these pest anemones at a minimum. If they have gone to foothold, it is eventually very difficult to get rid of them. If you are finding it difficult to identify or are not able to get rid of them, it would be better than you ask Pest Control Fairfield CT for some advice. If it would be a pest that will harm your corals, this could be helpful if they are not pests, you would be sure that no pest will harm your corals.

[coryscritch]

Did you figure out what these are?I also have a few in my tank.