As I was inspecting my tank I noticed something that didn't look like algae growing on the side of the tank. Upon a closer look they resembled an anemone or sea lily but this a freshwater aquarium I'm looking into so I'm completely perplexed on what they are. They are growing on some of the rocks too. I'll do my best to give a description, they are white with stalks about 3-4mm long and at the end they have 6 tentacles. Some even have little ones branching off of them. Could anyone tell me what these things are?

something like this? I believe they are called Xenia. However I thought they were only found in marine environments. Sorry, haven't got any other suggestions apart from it is probably a harmless organism.

sounds interesting, pls post pics if you can

I'll try and get some macro shots of them later

A pic would be helpful but it sounds like a harmless growth to me. Probably feeding on excess food

Few questions

How long has the tank been set up
Do you overfeed- only feed what your fish will eat in 2 mins
Do you clean the gravel and change water regulary
Post test results for ammonia, nitrite and nitrate

Here are some pics if I do it right.IMG] i988.photobucket.com/albums/af10/jtomazinis/Picture011.jpg [/IMG]
I hope I did it right...

To answer your questions delboybully the tank has been set up for about 3 years. I don't over feed my fish and lately, due to some spare time, I've been doing water changes every two days. I'd like to think I keep a clean aquarium. The ammonia levels are low enough to not show during tests and the ph is neutral. I don't have a nitrite or nitrate test kit otherwise I would give those measurements. Some changes in the past month have been, a small amount of hornwort has been added and sand substrate was put in last week. Thats about it. Hopefully the pics help.

sorry, I have never seen this before. It worries you then just take the rocks out and clean them

I find it kind of interesting. The only thing that concerns me is that I don't know if these things will get to the point where they take over my tank, but so far their growth rates don't seem to be too fast so I guess I'm going to see where it goes.

They kinda look like hydra but white...I would assume they're a harmless type of algae/plant growth..but yeah, that's odd.

is it mucus like?

I believe they could possibly be CNIDARIAN HYDRA..