ID please.

[Dandy]

Curious what this is and if it is dangerous to my tank. They are currently in my sump.

 

[DDenny]

Looks like pineapple sponges

 

[Paleozoic_reefer]

Looks like you also got some grape calerpa. Good for nutrient control, but make sure you keep it in the sump. It can spread very fast and is difficult to remove.

 

[Dandy]

that is all in the sump,

 

[Dandy]

That's my sump setup currently. Need to finish my stand.