Worms & Weird Tank Discovery (NEED IDS)

[bootz]

During my latest water change i noticed a few small white/transparent worms too tiny to photograph. I have not added anything new to my tank in 4 months and when i do i use iodine based coral dips. Additionally, when i started my tank over a year ago i used both dry rock and dry sand. Anyone have any clues as to what this worm could be and is it harmful? However, my second discovery can be photographed and i am hoping it is not Aiptasia.

 

[scottkraft]

the small white worms are prolly sand worms and are not harmful in my experience. Your second does not look like aptasia, aptasia looks like a brown anem most times
Scott

 

[bootz]

yeah i figured it was a pineapple sponge. As for the worms i am still researching them.

 

[crister13]

Could they be flatworms?