Does anyone know what this red stuff is

[macara.brooks]

I added a live rock and now I have this red stuff

 

[shakacuz]

live rock tend to have things like aiptasia, feather dusters, and the like. what you have circled is too small to be able to properly ID, but my guess is its some kind of invertebrate like aiptasia or ball anemone

 

[lil sumpin]

The thin tubes on the right side look like they could be vermetid snails and I think the red stuff might be coralline or peysonellia algae.

 

[macara.brooks]

The thin tubes on the right side look like they could be vermetid snails and I think the red stuff might be coralline or peysonellia algae.

Will it harm my tank?

 

[OriginalUserName]

Foraminiferans it looks like. If so, harmless and a good indicator of healthy activity.

Edit, the circle on the right looks different. Hard to tell from pic.

 

[lil sumpin]

Vermetids can bug coral but I wouldn’t fret. A few here and there are not gonna ruin your tank, can always remove them or put a little superglue into the opening of their tube. The red stuff is good. All in all, a neat little bit of biodiversity