What is this stuff?

[Hondanation09]

An someone identify some stuff for
me?





Is this some sort of sponge ?





Light green thing and red branch like structures





Stringy white stuff attached to rock and some poking out of Rick here and there

Keep in mind tank is now in 4th day...readings 0 ammonia, 0 nitrite, 10 nitrate using 30lbs live rock and Seachem stability.

 

[Fish-guy]

First one looks like a dead coral