Stop the bubbles! Bubble algae can look interesting when you first see it. Many have even made the mistake of finding it on new live rock and deciding just to leave it alone. Once their tank dipped into this algaes growth zone though they quickly changed their mind.
Often introduced on new live rock bubble algae can under the right conditions take over a tank. It will overgrow and kill out corals and coralline algae. Its primary food source is the nitrogen and phosphates in your water. Keeping your parameters in check with proper filtration is always the best way to keep this beats at bay. Some algae eaters including tangs and emerald crabs have been known to eat at it as it pops up too.
More than one type of bubble
What most aquarists refer to as bubble algae can actually be one of several different types of algae. Ventricaria ventricosa is the most common but others are Boergesenia forbesii, Valonia aegagropila, and Valonia macrophysa to name just a few. They all grow very similarly as little green bubble sacks. Different species will grow to different max sizes usually ranging from the size of a pea to size of a large marble. Some species will be perfectly spherical while others will be somewhat elongated and almost branching.
How does bubble algae grow?
Feeding on the nutrients in your water (primarily nitrates) these algae will grow until they burst. As they burst thousands of little bubble algae spores are released into the water, each with the potential to attach to a surface and grow into a new bubble repeating the process.
The biggest problem most aquarists encounter is even with just a few small bubbles in your tank; if the conditions are right for growth on bubble can quickly take over a rock after rupturing going from what didn’t even seen like a problem to WTF situation very quickly.
How do you remove bubble algae?
If you already have bubbles in your tank, just remove them. Be careful and do your best not to let them rupture as you remove them. Often they can be removed by hand, preferably wearing some sort of protective gloves since the rocks they grow on can be sharp. If needed use a small straight edge tool like a screwdriver, chisel, etc. work around the base of the bubble to dislodge it.
Having a syphon going while you do this to suck up the bubbles is very handy. Bubbles can easily float away as you work lodging themselves somewhere else. I like to clamp a filter sock inside my sump and run a syphon from the display into the sock. This keeps the water in the system and catches all the bubbles in the sock for easy removal once done.
What eats bubble algae?
Some creatures will eat bubble algae. Yellow Tangs, Rabitfish, and Emerald Crabs among others have a reputation for eating this algae. Like with all nuisance algae though for every story I hear about someone using these to clear the algae I hear another about them not touching the stuff. It really just depends on you specific animal and what the other food conditions are in the tank. Think about it, I like burgers and pizza but if I had both in front of me I’m going with the burger fist; you might go for the pizza. The same logic applies to these guys.
Really it is a good idea if you like the creatures and your tank can sustain them even once an outbreak is gone to add them to help. Just don’t rely on the creatures or they may let you down.
Prevent bubble algae by removing its food source
The best way to prevent a breakout and even to get rid of an existing one, is to remove its food source. If your tank is running at near 0 nitrates algae has a very hard time growing. This is why regularly changing your filter media like your socks and having a protein skimmer are very important. This will remove a lot of the organics that decompose into nitrates to feed the algae.
Grow this instead and prevent bubble algae
As much as we push to keep our nitrates low by not over feeding and removing organics with mechanical filtration; we still feed our fish and then they poop. Maybe that gets picked up by your cleanup crew but then they poop too. Eventually something dies. A great way to pull the excess nutrients out of your tank is actually by growing algae.
Setting up a refugium to grow an algae like chaetomorpha encourages this algae to grow in an unseen location in your stand and not in your display tank. You simply let it grow and cut back the growth every so often removing the cuttings from the tank. This helps ensure you are actually taking out the nutrients that feed the algae not just transferring it from one form to another until, well until the conditions are just right for a terrible algae bloom.
To wrap this article up, it is always best to prevent than to cure. Inspect your new live rock and coral frags for any hitchhikers you can remove. It is always best to quarantine them to be safe. That helps to keep it out to begin with.
Once introduced into your tank the best prevention is to deprive it of food. Keep the nitrate levels low with good filtration and nutrient removal systems. If you are faced with this growing, do your best to remove the bubbles without rupturing them as this releases the spores into the tank for more to potentially grow.
A well-written Article by Dan