Grass?

[FireEater]

This stuff just started growing in tank about 4 days ago. It is on a spot at top of tank on a rock.
It is green and looks just like the plastic grass that goes in Easter baskets. So far it is about 3" long in places and doesn't seem to have spread more than a 5" radius.
I'll try and get a pic, though now the lights are off due to new percula in tank.
Thanks!

[Pineapple House]

Sounds quite a bit like a form of hair algea. This is a real pest, as sometimes it can take over the whole tank, if not watched close enough. When you have this in abundance, you need snails. Turbos, Astreas, Margaritas, etc. They love this stuff. If you have high phosphates and some high nitrates, you might start to see this stuff. One of the best ways of removel, it by picking it up by hand. But try to make sure you dont leave any setting on top of the water.

That's just from the discroption you gave us, so im not exactly sure if it would be a species of hair algea. A picture would greatly help us!

Also, moving to the UFO (Unidentifies Fishtank Objects) forum, where you will get much better answers than the general reef forum :-)

PH =)

[Irisservice]

Sounds like hair alge!
Post a Photo for a better answer.

[Almarktool]

def sounds like green hair alge i just finished getting rid of a large outbreak of it on my 250 lbs of live rock, i used a alge blenny and a emperator angel they cleaned it up in about 2 weeks

[carol]

I have the same stuff too! sorry dont know what it is but my new tubos love it! :D

[FireEater]

Here is a pic of it.

[Mark Anderberg]

The good news is that it is not Hair Algae. You have a form of Macro Algae growing and it is a good thing. If you have a tang in the tank they will help keep it under control. If not, add one and they will be a happy camper. If the Macro Algae begins to take over it is easy enough to remove manually.

Best Regards MDA

[Bob Ashcraft]

Looks like a form of Caulerpa. You're lucky, I had to buy what I have.

[FireEater]

Thanks for the replies!
Maybe I can transplant some down in my fuge.
It is on a rock I got from the beach on Galveston Island. It wasn't there when I first got the rock or I didn't notice. I found it washed up along the jettys after a storm and it had 2 rock anemones on it. Though one was dead, I scraped him off and cleaned the rock real good in the surf. The other anemone is doing great.
:D

[OscarBeast]

A rock anemone? AKA aiptasia?

Many reefers spend hours of their time killing off these pests. They multiply like mad and have a harsh sting that will kill most corals. This is not something that people usually add to their tank.

If you are planning on having a reef tank, then you may want to make the other one dead as well.

Here is a picture of aiptasia. If this looks like your little friend and you are going to have a reef tank, you may want to get rid of it while you still can.

[FireEater]

Luckily they are not aptaisa. They are anemones that grow along the jetties on Galveston Island.