Purple Sponges?

[Mr. Microscope]

When I started my tank two months ago, there was what I thought was purple coralline on the LR. It continued to get thicker and thicker. I came back from vacation today to find it now looks like this. I think they might be sponges. Any thoughts? I think the one on the top is new.

[lakshwadeep]

Yes, those are sponges. If you touch them, they should feel spongy. Some may not survive if exposed to direct light.

[yardboy]

Sponges are nearly as common as corals on a reef, but can be finicky in an aquarium. Most types are quite welcome, especially the more colorful ones. There is even a whole discipline involving uses sponges as a filtration mechanism known as "cryptic filtration"

i've only had one sponge be a problem, light gray in color, that can take over if not watched. Fortunately relatively easy to get rid of.

Those you have are quite nice looking. And in case someone requests a frag, most sponges are very hard to transplant. But oddly they appear quite frequently when we aren't trying!

[AdrianBryce]

+1 on the sponge. I have tons of sponge growth in my tank. Neon green, yellow, purple, gray, black( I know, a weird color). Also, FWIW every sponge in my tank has been exposed to air for at least 10 minutes with no adverse reactions. Super Sponges.