what is this thing

I was cleaning my glass and noticed an abundance of these small Star like critters on my glass. They’re tiny - like a thin point to a lead pencil. To my eye they look like 4 pointed or Star shaped, but my phone was able to take a pretty detailed photo. Here are two different ones. ‍♂️ curious...

I have a 10 gallon reef tank and i have this new fellow and i don’t know wat they are. i got it first from some algee and i thought it was sand or soemthing and then it started to grow in size from an inch to maybe half an inch.

So I thought this was hard but it turns out it’s not not hard so i’m guessing sponge? What kind is this??? It just started growing in my tank randomly and I have no idea what it is

So I’ve been trying to figure out what this is and I can’t figure it out! It just started growing in my tank one day and now it’s huge. I thought it was soft but it’s hard! Anyone know what it is?

HELLO, I was cleaning my tank and this came out of my power head lol. I have no idea how it got there or what it is....please help lol.

Hey guys, pretty new to reefing but I have an Semi established tank, I think it’s been like 4-5 months since I started with Tampa Bay live rock. But I looked at the glass today and saw something hatching? I didn’t see these eggs yesterday or last night but there seems to be little “sprouts”...

Notice 2 of these on my rock.

Started getting these all over glass. Any ideas?

Hello, a friend of mine has a setosa and would like to know about these little antennas sticking out of the coral. They move in the flow and retract on contact, like a feather duster. Are they any reason to be concerned or to dip the coral? Could they cause the polyps to not extend fully...

So I picked up this neat little coral about 2 months ago. I was told that it was a “finger leather”, but I really don’t believe this is true. When I first got it in my QT it opened up and was a beautiful blackish- purplish- peachy color with a main stem and branch pattern. After 2 weeks in QT I...