Hondatek
Aquarium Advice Addict
These purple globs have been growing for a while now . They started off small but now I have a baseball sized colony on top of the sump pump along with some growing on the drain pipe out of the water . Also have them on the return line growing out of the tank . So I don't think they are sponges and I am tired of not knowing . Pics are the ones on the return . Thanks .