Is this a good thing or a bad thing.

[jfishwild]

Like the title says I have this in my tank and it is taking over this rock. I thing it's a sponge. But not sure it's yellowsish in color. So is it good or bad?  And what is it.

[jfishwild]

A little better picture sorry my Camera not the best.

[lazylivin]

You probrably have some oil on lens of phone. Try cleaning it with a microfiber cloth. If it is an iphone lens is glass and you can use windex and paper towel.
Normaly  sponge is good because it typically only grows in dark areas, stengthens rock structure and  to an extent polishes the water. However if it is growing in lighted areas creating an eye sore or crowding out coral the. It may be undesirable. If that is the case there are fish that love it depending on type.

[jfishwild]

What fish will eat it?

[lazylivin]

Almost all angels and many other types of fish.

[jfishwild]

i have 2 angles in my tank now a flame and a lemon peel and they are not touching it?