Something on my rock

[912jake]

Not sure what this is but i noticed it after i moved this old piece of live rock to my 30 gallon from my 10 and it seems to be getting bigger just wanted to know what it is and if it is dangerous to my tank. thanks

 

[bjohanson1234]

Thats an apstasia. Its sting will harm corals and they will take over a tank. Kill it with apstasia X

 

[wontonflip]

+1 bj -- kill it kill it kill it!! I used Joe's Juice. Worked great. But I've heard great things about Aiptasia x as well. If you have a lot more than just the one, maybe try getting some peppermint shrimp to eat them. but if it's just that one, Joe's Juice or Aiptasia X is fine.