Help, unknown growth!

[cashemin44]

[ooking for some help. A friend and i were examining my tank and noticed these bizarre creatures. I was wondering if anyone knew what they might be and if so are they bad for my tank? I have a 55 gal with rock but its not live. I have a picasso trigger, one clown and regal tang. My levels are normal although my temp for my tank is on the higher side or normal. Any info would be great!

[Mmckibben]

ummm, pics or descriptions...

[xCry0x]

ummm, pics or descriptions...

Lol no kidding.

+1,000

[cashemin44]

I'm having trouble posting a pic....I hope this URL works

http://cdn.saltwaterfish.com/d/d0/d0a1349e_IMG_20110922_183616.jpeg

[cashemin44]

Sorry about the pic issue....let me know if the url gives you trouble. Thanks for looking and trying to help.

[StephLionfish]

Looks like hydroids. Bad.

[cashemin44]

Where do they generate from? I dont have live rock in my tank. Is it possible they could have come from live sand? We added a new bag in the springtime but havent had any issues up until now. Never had anything like this in my tank before. Will it harm my fish?

[dzhuo]

These are Clava sp. (a type of hydroid):

http://emeralddiving.com/images/White%20Hydroid.jpg

Or Cnidarians Hydra (a type of jellyfish):

http://www.tvcc.edu/depts/Biology/HotPot/Images/Biol%201407/hydra.jpg

Between the 2, my guess would be hydriod. I would remove them (or technically remove it since this is a single animal). Clava sp. is actually pretty rare so I wonder where you get it.

[Scribe]

+1 on the hydroids. My tank was covered in them....All the rock is out now waiting for them to die off. Only suggestions I ever got on removal was kalk paste. Didn't do much long term.

[maymania6]

Is take every rock with hydroids out and scrub the heck out if it. Then let it dry completely out for a week or more before adding it back. Thats a pretty serious infestation!