whats this

I found this the other day and then it disappeared. I didn't see it anymore! Could it be a baby cucumber? It reminds me of hot dogs, and I don't have that kind of cucumber

Hi! My husband and I are new to saltwater tanks, and I know absolutely nothing! I've been trying to look this up, but not even sure what to look up. Does anyone know what this is, should we be worried, should we take it out? It looks more brown in person, not so much green.

Hello everyone So in the beginning of February I broke down my 75 gallon display tank bleached all the live rock except for one that had a mushroom coral attached to it. In preparation for my 125 gallon upgrade. I removed some substrate along with that rock to house long tentacle, my bubble tip...

Some cool acro

Some kinda cool acro nub

I have a 14 month old tank. Haven’t had any pests in the tank ever found my first unknown creature I moved a rock and he was in the sand both are wiggling even tho I only saw one in the tank, maybe I cut him in half when I suckef him out idk. What y’all think. Also I haven’t put anything new in...

Hey y’all so I have 2 nassarius snails. They hang in the sand mostly but every so often they will zip around the glass before either eating or just burrying themselves. However this snail Has been in the corner of the tank all day and has left these werid feather like markings along the glass. I...

Started noticing these little hair lookin guys in spots on my rock, wondering what they could be? Hydroids maybe?

Hey, I just got a new frag ( very excited! Getting my first sps corals) I noticed that it had something on the side of it Lfs said detritus It’s crusty and hard feeling but broke up quite a bit in the Dip Any ideas if it’s an issue? Sorry I couldn’t get better photos