Tank pics, identify somethings please?

[skimmer247]

Hey so I have 13 lbs of live rock in my 20g L and here are some pictures. I bought live rock from 2 different locations, 5.5lbs has tons of hitchhikers and coralline algae, and the other 7.5 lbs is practically bare (some hair algae.) How long should it take for the coralline to spread to the other rocks, does they have to be touching? Can you identify any of the living things you guys see?

On the hair algae, since it did not pop up in my tank, and since i have the correct water parameters, will it keep growing? spread? die off?

 

[Drix]

# 1 is a ricordea mushroom (coral)
# 2 is a feather duster (harmless filter feeder)
# 3 is Zoanthids (coral)
# 4 looks like another ricordea
# 5 more zoanthids

Luckly the coral you have are a good choice for beginners and adapt well to low lighting. I'd read about them in the coral forums, Zoanthids have their own forum Ricordea's can be found in the Corallimorpharians forum.

Looks good

 

[skimmer247]

Do I have an oyster i the 3rd pic? I thought it was just a shell when it came, but I saw it slightly open and then it closed then i tapped the tank glass.

 

[Skipper]

No, doesn't appear to be an oyster to me. Probably some similar bivalve, though. Fairly common on live rocks.

1 & 3 are just plain ole mushrooms, not ricordea.