Weird white tubes near zoas

Hello! Months ago i bought some zoanthids and most of them died because they fell of the branch they where at and got lost either between rocks or the anemones got them.
Right now, months later i have 6 of the surviving zoas and... where the other where at (the ones that died) there is some white tubes growing, anyone what is that thing?
Heres a pic:


do you feed the zoas? can you take a pic of them face on, so I can see the polyps of the zoas?
The Zoas are the things under the cirlce, while the tubes are the arrow pointed WTF's:

The White Tubes are the THINGZ under the cirlce:

bang guy

Neither. They won't harm anything.
That white filiment looking stuff you are wondering about is just a sponge. It won't harm anything either.
You do have a HUGE Aiptasia at the top of the first picture. If you have small fish there is a small chance it could harm them. That particular species of Aiptasia doesn't reproduce as rapidly as others.
I know about the aiptasia, thats a Warty anemone, i got 3 others: 2 Corkscrew anemone and a strangely weird green colored Banded Tube Dwelling-Anemone. They are just fine, my parrotfish keeps them from reproducing and my other fish don't get bothered by them.
Well since my last post.... the sponge is growing and my zoas are irrated (3 died ;~;) and the sponges are taking all over the place the sponge even grows on other plants!!! CAN SOMEONE GIVE ME A SOLUTION!?! also.... why kill the parrotfish? :c

bang guy

You have introduced organisms from various oceans into your aquarium. If you release anything from your tank into the wild there is a risk of ecological disaster. This has already happened several times. Don't be the source of the next one. Please!
How you know I have gathered fish from other oceans? I found the parrotfish at a local beach dying of parasites, so I took care of him without noticing how big he was gonna get...