strange things growing on my live rock

Anybody have any ideas what these things are? They have appeared just in the last few days on live rock that is several months old.

 

are you talking about the white things or the green specs. White things are Pineapple sponges totally harmless. They will die off when the nutrients lower. I tell my kids that its Sponge Bobs house.

 

Harmless filter feeder, think of them as tiny filters for your tank

 

Thanks! Yes, I was talking about the bigger white things. If they die off with less nutrient, does this sudden appearance mean I'm feeding too much, or not changing water enough or something like that? Would the light over the tank make any difference? They didn't show up until I put my new LED lights over the tank.

The "green spots" actually aren't green, it's a combination of reflections on the wet rock and tiny white things that are growing all over the tank. They look greenish because of the blue light from the tank. Those guys look sort of like little barnacles of some type, but they're probably not. They are either circular with an empty middle or like little C's. I've seen them in other people's pictures on here. I don't think they're a problem.

 

Light has no effect on the sponges as they're non-photosynthetic. They're relatively common in newer systems that were started with live rock and/or sand, but as already mentioned, are fairly short-lived.

The circular white spots are most likely micro-featherdusters, another harmless filter-feeder.

 

OK, thanks.