A few months ago, I noticed a yellow mass growing on rock behind a coral. After a recent water change the mass suddenly expanded, forming, an approximately 3-4 X 1 inch column (picture attached). This is not the first time a yellow growth has appeared in this tank. When first established -over 15 yrs. ago, it was not uncommon for small yellow growths to appear for short periods of time. This is the first time one has increased in size and so suddenly.
Could anyone confirm this is a sponge? Any thoughts on this sudden growth? I've been treating the tank for an overgrowth of green and red algae and physically removed a significant amount during the water change. Do sponges, if this is one, feed on algae?
Could anyone confirm this is a sponge? Any thoughts on this sudden growth? I've been treating the tank for an overgrowth of green and red algae and physically removed a significant amount during the water change. Do sponges, if this is one, feed on algae?