Is this good or bad?

[Shawn Boe]

Just noticed this today and I don't know if it's a pest or not!

 

[vetteguy53081]

Hard to confirm what it is under heavy blue light but may be an aptasia
Remove frag and scrape it off into toilet

 

[brmc1985]

Hss add rd to confirm what it is under heavy blue light but may be an aptasia
Remove frag and scrape it off into toilet

“Scrape it off into toilet”. Lol. I want to put a cup of salt in my toilet and do this and see how long it would live in there.

 

[brmc1985]

Just noticed this today and I don't know if it's a pest or not!

I agree with vetteguy. Probably aptasia. If the toilet doesn’t kill it your next best choice is to set the house on fire and rebuild from scratch. Sarcasm…but only mild

 

[JPM San Diego]

Wait, don't kill it yet. We need better, white light, photos to be sure what it is.
I really can't tell, but the tentacles look a bit thick and straight for aiptasia. Better photos please

 

[dk2nt9]

Take a look at pictures of aiptasia and see if this is what you have. Scraping could be not enough, read about aiptasia removing methods. Covering it completely with superglue should work better.