Flower on live rock

[egwich]

Was doing a water change and found this guy growing. Good, bad, should I remove it?

 

[DSC reef]

That looks like aptasia. Bad and invasive pest

 

[DesertReefBoy]

Yup agreed. Looks like aptasia. If you can I would remove the rock, pull the aptasia off with tweezers, rinse the rock with salt water (maybe with water change water) and put the rock back in the tank.
If you cant remove the rock there a hundreds of ideas people have. I’ve tried using kalkwiser powder mixed with a little tank water to make a thick paste. Grab a 10 mL syringe suck it up and slowly squirt a little paste in the mouth of the aptasia. Make sure the aptasia grabs the paste and eats it. This normally kills it.
There are other fish and shrimp that eat the aptasia as well. Peppermint shrimp and worked for me. I’ve heard some file fish eat it as well.
Lastly don’t just pluck it out of the tank or disturb it. It could possibly send out seeds and you will see more in your tank.

 

[theKoolAidMan]

Def not a flower you want to have. That's Aptasia Anemone. It grows and spread extremely quickly and packs a sting strong enough to really hurt your coral. You will want to get rid of it as others suggested. If you can remove the rock, that is the easiest way. I think injecting it with kalk of AptasiaX would be difficult due to it's location.

I recently discovered one that came in on a frag. Eventually got around to dealing with it. Added 4 peppermint shrimp and the dang thing didn't last the first night. They enjoyed their snack.

 

[Reefin Ryan]

i prefer removing it then watching the spot like a hawk the next few days and if there is ANY sign of it growing back I put some super glue over it which is a garunteed kill. they can grow back from virtually no remaining tissue when removed so the superglue makes sure that is not going to happen.

 

[eggplantparrot]

Grow it in a jar