Bubble Algae Eating Fish, Cutting It Open and Removal

Welcome to our Algae Bubble Care Guide! Whether you’re a beginner or an experienced hobbyist, we’ve got you covered. Here we explain what bubble algae is and its impact on your aquatic environment, while offering you safe and effective elimination methods. From manual removal techniques to natural and chemical remedies, we’ll explore various approaches that suit different preferences and tank setups.

Get ready to say goodbye to those unwanted bubbles and restore the beauty of your aquatic habitat. Let’s dive in together and take control of the bubble algae situation!

What is Bubble Algae?

Algae bubble, or Valonia ventricosa is a pesky form of algae that can quickly take over your reef or saltwater tank. Also known as sea pearls or sailor’s eyeballs, bubble algae is a widespread species in tropical and subtropical oceans that mostly clings to live rock and mangrove roots. It can enter your tank undetected when you unintentionally add a contaminated rock or piece of coral.

When you first notice bubble algae in your aquarium, you may find them interesting, even attractive. Its bright green “bubbles” catch the eye and may seem harmless at first glance. However, under the right conditions, this algae will quickly spread from your live rock to your coral and any other accessible hard surface. When the bubbles break loose, they can clog your overflow tubes, inlets, and substrate void.

Author’s note: Besides ruining the aesthetics of your reef tank, they will also safely prevent the growth of your precious corals. You can’t rely on your tangs, sea urchins, or blennies alone to fix the problem. It is best to eliminate any signs of bubble algae immediately before the problem spreads and upsets the peaceful balance of your aquarium.

Bubble Algae Propagation in a Saltwater Aquarium


Bubble algae can have rounded or tubular green nodes that vary greatly in size and color. While it’s easier to spot the quarter-sized variants, you should also watch for the pea-sized bubbles lurking in the interstices of your live stone.. Depending on the species, your Bubble Algae can be elongated, pitted or slimy. They can grow in clusters but can also appear isolated.

This algae uses an anchoring component called hold-fast to hold it in place. The bubbles, also called bladders or vesicles, carry spores which spread when the algae burst.

Red vs green bubble algae and other species

The most common form of Bubble Algae in hobbyist tanks is Valonia ventricosa. This particular species forms some of the largest green bubbles.

While green is the most commonly seen variant, you may also come across red bubble algae also known as red grape algae or by its scientific name as Botryocladia botryoides. This algae thrives on the nitrate and phosphate in the tank and if it bursts or deflates, it will release spores which will allow it to spread fairly quickly.

Other species to watch out for include:

  • Dictyosphaeria ocellata. Experienced aquarists hate this bright green algae because of its innate stickiness.
  • Boergesenia. These bright green bubbles usually grow on coral debris in small, scattered clumps and can be identified because they have longer bubbles.
  • Dictyosphaeria cavernosa. Known as green bubble algae, this algae is recognizable by its pitted nature which becomes more noticeable as the bubbles grow larger.

Cut a bubble seaweed

There is some debate over whether hobbyists should pop the Bubble Algae to remove it from the tank. Given the structure of these algae bubbles, bursting them can release more spores into your tank. Destroying or cutting multiple bubble algae at once can even result in a full infestation.

However, the actual risk of spores may depend on the size of the Bubble Algae vesicle. If it bursts young, you probably won’t have to worry about future bubbles. It is also important to note that any spores released into the tank will need to avoid your fish and filter equipment and find a suitable place for undisturbed growth.

Author’s note: Overall, you shouldn’t experience any significant issues when scraping young Bubble Algae. If you notice remains left behind, scrub the live rock with a toothbrush or similar tool to remove any residue. When dealing with larger blisters, try to keep them as intact as possible to limit the chance of regrowth.

Algae bubble eating fish

Fortunately, there are several large species of invertebrates and vertebrates that munch on this algae. Emerald Crabs are one of the best lines of defense against this invasive bubble algae since they love to eat it. However, a well-fed crab may be more interested in other, tastier omnivorous options. Be sure to keep your tank clean and avoid overfeeding them so they continue to eat the algae.

Other species that can help with your bubble algae outbreak include:

Grazing herbivores are incredibly effective at tending to your aquarium’s bubble algae population. Sea hares in particular feed only on this algae, which can put them at risk of starvation once it has been completely eliminated.

Author’s note: To prevent any of your fish or invertebrates from dying and worsening your water quality, make sure you have a backup feeding plan in place to keep your aquarium healthy.

Is it a unicellular or multicellular organism?

Bubble Algae is unicellular or unicellular organism. It is one of the largest single-celled species in the world. Each bubble or vesicle is a cell and is full of nuclei floating in cytoplasmic substance.

These bubbles house thousands of cores, or building blocks, which are ready to create more bubble algae. In nature, the vesicles will grow to a certain size and burst to continue their natural life cycle.

Eliminate Algae Bubbles

Having an algae bubble problem won’t harm your fish, but it can slowly smother your corals. It will also eventually become unsightly and invade all surfaces of your tank. Here’s how you can effectively remove that pesky algae before it ruins your beautiful aquascaping.

1. Manual removal

If you discover your Bubble Algae early, you can easily remove it by hand or with a sharp screwdriver. To prevent the organism from coming back, you must remove the blister completely, including its anchors. Gently grasp the base of the bubble and twist it out. You can then use a siphon to suck up the remains before they fall into the live rock below.

Author’s note: Structures heavily blistered should be removed from the tank and cleaned. Clean them aggressively in a separate bucket of salt water. Unlike other species of algae, Bubble Algae does not need a lot of direct sunlight to grow. Check carefully under other rocks, structures and shady spots for any other bubbles.

2. Refuse nutrients

You can also control your bubble algae population by limiting the nutrients they have access to. Other microalgae like Caulerpa and Chaetomorpha require a similar diet and will help you starve the Bubble Algae.

Another option is coralline algae, which forms a crust on some surfaces and prevents blisters from spreading. Adding these microalgae can make it more difficult for bubble algae to grow, but it cannot completely eliminate it from your tank.

3. Introduce new fish

Marine fish like blennies can spend days scooping up your live rock and foraging for tasty morsels of algae. Most of the best algae eaters require a lot of space in the tank. They tend to become aggressive towards other tank mates who encroach on their perceived territory. Be sure to research any species you are considering adding to make sure they will get along with your current fish.

Prevent bubble algae

You are encouraged to designate a specific corner of your tank to this fascinating algae. With routine maintenance and proper checking, they can add a fun splash of color and originality. While some hobbyists keep these algae in their tanks, many others prefer to practice strict preventative procedures to avoid any outbreaks.

1. Quarantine new releases

All new additions of your live rock to your coral plugs should be reviewed and quarantined until deemed safe. These acquisitions are full of cracks and hidden places where Bubble Algae spores can hide. You want to give the vesicles time to grow so you can catch them before placing the device in the tank.

2. Useful household

Housekeeping options like investing in turbo snails can prevent any algae from taking hold permanently. These snails will only help stop an epidemic. They have very small mouths and won’t be much help in eliminating an existing infestation. These snails can actually make your bubble algae problem worse if they poke holes in the blisters.

3. Adjust aquarium conditions

Many experts believe Bubble Algae requires excess nitrates and phosphates. Try to keep your nitrates below 20 ppm and your phosphates below 0.03 ppm. You can manage these chemical levels by performing partial water changes every two weeks and quality testing.

Author’s note: It may also be helpful to use a protein skimmer or a separate, insulated refuge to safely stimulate the growth of your microalgae.

A Valonia ventricosa growing next to some plants


In conclusion, successfully removing algae bubbles from your aquarium or pond is essential to maintaining a healthy and visually appealing aquatic environment.

Remember to regularly inspect your aquarium, maintain proper water parameters, and practice good fishkeeping habits to minimize the chance of bubble algae reappearing. Be patient and persistent in your removal efforts, as complete algae eradication may take some time.

We hope this guide has provided you with valuable information and practical solutions for dealing with bubble algae. If you have successfully removed it from your aquarium and want to learn more about caring for your corals, try these care guides.

By the way, don’t forget to tag us on Facebook when you share before and after photos of your tank’s algae bubbles. Thanks for dropping by!

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