What are these?

[MikeP]

These things are bad right? What are they and how do I get rid of them?

[Jason McK]

Ya that would be Aptasia

[Slick Fork]

I've had good luck with Joe's Juice.

[Beverly]

Yup. Aiptasia. I inject them with calcium supplement using a needle tipped one ml syringe. Vinegar also works, but it will lower pH. Inject 2 or 3 times at various angles to make sure you get the syringe tip into the aiptasia once it shrivels up when you approach it. You may have to do this one a few occasions if you don't inject it properly the first few times. No big deal. Just keep after them.

[MikeP]

Thanks, luckily they are in my 'holding' tank and not in the display. Should be nice and easy to take care of em. Just out of curiosity is there something that eats aiptasia?

[adidas]

Thanks, luckily they are in my 'holding' tank and not in the display. Should be nice and easy to take care of em. Just out of curiosity is there something that eats aiptasia?

peppermint shrimp

[Pan]

copperbands eat them as well