Pictured this week is actually something many of you might not want to see. It’s the dreaded Valonia bubble algae, and the terror of many reef aquariums. This tiny algae, as you can tell, grows in the form of a bubble. And even though most of the bubbles you encounter will be small, many can get quite large, even a couple of inches in diameter. The bubble algae actually attaches to a substrate, usually under a rock or in a crevice, and it constantly shows up in the middle of Zoanthid colonies.
The Valonia have long been rumored to release spores when popped under water. Others speculated that the water within the bubbles contains nitrates. While nobody knows for sure what’s inside the Valonia, these bubbles do rupture and they do seem to pop up just about everywhere in a saltwater aquarium. If your tank becomes infested with these bubbles, you can try to employ an emerald crab to clean them up. Otherwise, you might have to hand pick them from the rocks.