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FAQs about Bubble Algae Boergesenia, Dictyosphaeria, Valonia...)  In/Compatibility/Control

Related Articles: Caulerpa Algae, Green AlgaeAvoiding Algae Problems in Marine System Algae Control, Marine Maintenance, Nutrient Control and Export, Marine Scavengers, Snails, Hermit Crabs, Mithrax/Emerald Green Crabs, Sea Urchins, Blennies, Algae Filters, Ctenochaetus/Bristle Mouth Tangs, Zebrasoma/Sailfin Tangs, Skimmers, Skimmer Selection, Marine Algae, Coralline Algae, Green Algae, Brown Algae, Blue-Green "Algae"/(Cyanobacteria)Diatoms, Brown Algae

Related FAQs: Green Algae Control 1, Green Algae Control 2, Green Algae Control 3, Green/Hair Algae Control 4, Green/Hair Algae Control 5, Green Algae Control 6, Green Algae Control 7, & By Genus: Bryopsis & Derbesia, Bubble Algae (Boergesenia, Dictyosphaeria, Valonia...), Caulerpa Compatibility/Control, Other Green Algae, RefugiumsGreen Algae Control 1Marine Algae ID 1, Marine Algae ID 2, Marine Algae Control FAQs II, Marine Algaecide Use, Nutrient Limitation, Marine Algae Eaters, Culturing Macro-Algae; Controlling: BGA/Cyano, Red/Encrusting Algae, Green Algae, Brown/Diatom Algae

Ventricaria ventricosa, here in an aquarium. Generally an unwanted/pest algae species.

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Marine Aquarium Algae Control

by Robert (Bob) Fenner

Algae Identification; and Elysia use      12/10/14
To whomever this may concern,
I have a bit of Bryopsis and my tank is quite mature (8 yrs old) with plenty of algal types so I decided, after much research, to try my hand at a lettuce sea slug ( Elysia Crispata). I know many are marketed as eating Bryopsis, but am aware that there can be significant individual variation in diet with some preferring other types of macros.
<A valid concern>
My new lettuce slug, Berg, seen in the photo attached, has had no desire to eat any of my Bryopsis.
<Better choices about>

I have literally placed it there, like leading a horse to water, on numerous occasions, just to watch it crawl over it. I have been
vigilantly observing it to try to deduce what other algal types it might be eating so that I can provide for it by proactively seeking those out. So, I have this interesting algae I would like to try to ID ( pictured below).
It looks like little green translucent-ish stalks or stems. They are kind of stiffish and offer some resistance when you press on them, after which they bounce back to their original position. I put Berg next to it to see if it would eat it, and it did. So it seems I have successfully "identified" something it will eat, so now I want to actually identify it so I can get some because the tiny tuft I have ( pictured) wont grow fast enough to sustain Berg I think. What do you think it is?
<Mmm; can't quite make it out to be very sure; even after cropping, trying to optimize the pix... my guess is on Valonia macrophysa>
I also am trying to get my hands on a few other macros they have been documented to eat to try those out but thought this was a great lead for the time being. Thank you for the help and I very much appreciate your time and your thoughts on how to go about identifying the type of algae I have here.
<Had a few classes in Phycology... there are guides, dichotomous keys of use... need a simple microscope. If you get one (they're cheap, available) with a USB hook-up, send some high res. pix along. Bob Fenner>

cropped and enhanced.

Hey Bob,

I have noticed recently quite few green balls growing on my live rock. They are about 1cm in size, and I can see about thirty of them. I think they may be algae of some kind, and they look like they are starting to spread around my aquarium. How do I get rid of them?

Many Thanks

Mark Baker 

                There are a few approaches to limiting to eliminating such problem algae. Likely what you are seeing is some sort of colonial Chlorophyte (Green Algae), perhaps Valonia, Boergesenia, Ventricaria or Dictyosphaeria species.

                One front of attack as with all (pest) algae control is nutrient limitation… you can do your best to exclude, deny the introduction of nutrient in the first place… by using “clean” freshwater to make up your synthetic seawater, rinsing frozen/defrosted foods, eschewing the use of supplements and more that contain soluble nutrients, having good skimming and maintenance protocol period. Using competing macro-algae culture in competition for nutrient, best in an independently illuminated refugium, and large DSB for nutrient sinking are also profitable.

                The second war-front might be physical removal. This is best accomplished by utilizing an appropriate diametre syphon along with a “scraping stick”, ideally the latter affixed to the former… for scrubbing off the algal colonies while syphoning them out. Alternatively, if the algal balls are relegated to but a few rocks, taking these out and giving the spots a good scrubbing outside of the tank (and rinsing before returning) may eliminate them. Don’t make the mistake of thinking that you can ablate these balls and leave their bits in your system. Akin to cutting off the arms of starfishes, they will simply proliferate in your system from such activity.

                The last wave in your fight against these perceived pest algae is biological. There are organisms that do/will feed on them, but not to exclusion. That is, they may well prefer other foods. Mithraculus (formerly Mithrax), Emerald/Green crabs have been advanced as good controls, but they can get big, predaceous… Tangs of the genera Ctenochaetus (Bristletooths) and Zebrasoma (Sailfins) and some Siganids (Rabbitfishes) have shown promise as predators, assuring you have space, physiological as well as psychological for one.

                All three stated “fronts” are best applied together… as a sort of blitzkrieg against these algae. Oh, and I do want to issue a caution against stooping to chemical control/s. Algicides of all sorts are problematical in set-up, functional reefs, presenting the potential for total disaster. Do avoid their use.

                Finally a comment re not dreading these algal visitors… most “pass” of their own accord, and though seemingly unattractive, they don’t appear to pose much of a threat chemically or through physical crowding.

pH to kill bubble algae?     4/17/14
I recently had a friend tell me he had used a syringe to inject very-high pH fluid (RO water with 5-10 times the normal mix of buffer) in Ventricaria bubbles, causing them to wither and die.
<Mmm; might work... there are other means>
Have any of you ever seen this to be effective? Should there be so de effects to worry about? I am worried that spores would escape before the pH even affected them.
<Only way to tell is to try>
Also, he uses this same method to kill individual Zoo ploys that attach to other corals.
Thank you for your time,
<Use the search tool on WWM. Bob Fenner>

Bubble algae
Hey WWM crew this is the first time I have asked you guys and girls a question but have been reading your site for 2-3 years now and just can't find the answer to this question.
 I have an outbreak of bubble algae in my tank but it is only growing on the glass and pumps and I don't know how to get rid of it.
<Read here: http://www.wetwebmedia.com/BubbleAlgCont.htm
It is more of a clear color compared to the more common green bubble algae and it is still rather small
<Mmm, summat rate-limiting here. Bob Fenner>
and I don't know what to do.
Re: Bubble algae   2/6/12
Can you explain summat rate limiting to me please

<Ah yes; the term "summat" is an English colloquialism for "something or some things". What I intend is otherwise state-able as some thing/s rate limiting here... resulting in the smaller, lighter colored colonies you referred to. Likely some major nutrient like HPO4, or a dearth of alkalinity or alkaline earth material/s. BobF>
Re: Bubble algae

So what should i do just more water changes or is there a better method
<... read where you were initially referred. B>
Re: Bubble algae

Were i initially looked said physical removal is the best option but i cannot do that because it is only on the glass and from what i have read water changes do nothing so i need another option 
<... "and the linked files above">
Re: Bubble algae   2/6/12

Yes so i used a outside source(YouTube) and found a very affective method for removing this algae so thanks for your help
<Thanks for sharing><<Insubstantive>>

Bubble Algae: Valonia Control\Removal on LR. 4/30/2010
Dear WWM Crew
I have a nice looking rock in my sump that I would love to move in the display.
Problem is, it is covered with Bubble algae, and I mean you can barely see the rock!
<That is always a bit of a pain.>
Instead of manual removing or buying a crab I wanted to take it out, let it dry and clean it with a brush.
Would the Bubble come back even after a harsh treatment like this one?
<Likely so - Manual removal is about the only way I am aware of to completely get rid of it. There are chemicals that will kill it, but will usually kill the live rock as well.>
If you think it would come back, what else could I do???
<Manual removal I'm afraid. What has worked for me is to remove the rock, and have two buckets of water. I pick off as many bubbles as I can, then go at the rock with a toothbrush, when the bulk of the bubbles are off, I
rinse the rock in the other bucket.>
<You can read more about it here:
http://www.wetwebmedia.com/BubbleAlgCont.htm >
Thanks again
Without this site, internet is not worth browsing :D
<Thank you for the kind words.>

Bubble algae: Valonia sp. Bubble algae and control . 12/21/2009
<Hi Scott.>
My neighbor has a bad case of bubble algae.
<I know the feeling.>
I currently have 2 55 gal reef tanks that are beautiful. I want to help him figure out his problem. He has a 150 high with 2 265 power compacts. I looked at his tank and it is over run with bubble algae.
<The main culprit behind bubble algae is an excess of nutrients in the water column. Mithrax crabs will help in removal but can become a nuisance themselves. Regular, weekly water changes will bring the nutrients under
control, that and using other, desirable forms of macroalgae to out compete the bubble algae. Care must be used when physically removing the bubbles, as if they rupture during removal, they can spread their spores all over
the tank, making the problem worse. What I have found works best is physical removal of the larger bubbles, and then during the weekly water change, brushing some of the smaller ones off with a toothbrush, while siphoning any spores that get released.>
<It is a challenge, and one that does take a good amount of time, but eventually it gets it down to manageable levels. As long as the population does stay in check, the odd bubble or two does add a bit of visual interest
in my opinion.>
<You can read more about Bubble algae here:
http://www.wetwebmedia.com/BubbleAlgCont.htm >

Bubble Algae Control  -- 11/09/2009
How do you control bubble algae? I have just noticed a few popping up in my aquarium. I have read about the emerald crab or removing it by hand . What do you suggest?
< I would suggest gently removing them by hand. Mithrax crabs will help in removal but can become a nuisance themselves. >
Thank you , Cindy
< Your welcome. Ga Jenkins >

Bubble Algae Prevention 9/21/08
Thank you for your phenomenal efforts! I greatly appreciate all that you guys and gals do for the hobby!
<Thank you for your kind words Joe.>
My question today is about macro-algae of the Valonia sp.
<A pretty pest.>
I have been a marine hobbyist for 6 years and have had 1 FOWLR system as well as 2 reef systems, all with good success.
In each system, I have had/am having problems with bubble algae. This is a remarkable organism in the fact that it can flourish in a HUGE variety of water conditions. Even with near perfect water conditions and diligent extraction, it is still a problem in my systems.
<Can be very problematic.>
I have found that the often cited cures have limited results: protein skimming, carbon, and Mithrax Crabs have helped but IMO, do not offer a substantial solution. Manual extraction is the best method of control and this can be a real headache due to the organism’s swift reproduction!
<I would agree.>
Finally, my question. I am in the planning stages of a 75 gallon reef tank and would like to do everything that I can to prevent bubble algae from entering the system. I will be careful not to use specimens, live rock, or substrate from any tanks containing Valonia sp. and will use only freshly made synthetic water. I will be quarantining everything added to the tank for at least 6 weeks.
<All wise.>
Do you have any other suggestions on how to prevent this species from invading my system? I have noticed that even quarantined live rock can eventually appear with these green spawns of Satan!
<Well, though I am generally a huge fan of live rock, you might be interested in something like Marco Rocks, which is dried and has significantly less likelihood of bringing pests into your system. They just might be "Good for you!" More here:
http://www.marcorocks.com >
Thanks for all that you do! God bless!
<On behalf of Bob and the rest of the WWM crew, you're welcome.>
Joe W.
<Mich L.>

Algae Control/Bubble Algae 3/16/08
Hello crew,
<Hi Harry>
Over the past year I've had a small issue with bubble algae. I would manually remove the individual bubbles as I would see them and everything
would be under control. Now I am in the process of upgrading from a 75G to a 215G and I took down my 75 last weekend. As I was pulling out the live rock. I noticed the back had very large hard to get to bubble algae that I had not noticed before because they were facing the back. The large bubbles broke as I tried to remove them. I'm guessing they released all their spores.
Now to my question. I would love to solve the bubble algae problem before I put the rock back into my 215 because it will be very hard to
control in the new tank. How can I completely 100% kill it so it won't return I tried scrubbing the rock but that didn't solve the issue before.
Can I cook the rock, or maybe let it sit in freshwater for a few weeks? now that I have all the bubbles removed I'm worried about the spores. What will kill all the spores that popped permanently. I'm not averse to anything drastic at this point.
<Harry, I don't think it is necessary to put the rock into freshwater. Leaving it air dry for two weeks should kill the algae. After that process, I would thoroughly rinse the rock in fresh water. To prevent further outbreaks in your new tank, nutrient control is most important. Do read here and linked files above. http://www.wetwebmedia.com/nutrientcontrol.htm I have recently had an outbreak of this algae in my tank. I went to a more efficient skimmer (AquaC) and hired a couple of Emerald Crabs to help out. It is now gradually decreasing. Hope this helps you out.>
<You're welcome. James (Salty Dog)>

Bubble Algae… Boergesenia forbesii 11/25/2007
Hello Crew!
<Hi Dave! Mich with you tonight.>
I had already sent this email a few minutes ago but decided to resend it with a photo this time. Hope this doesn’t lead to any confusion.
<Nope! Think I grabbed both.>
I set up a 120-gallon tank 1 month ago, and have placed 3 small fish and 4 corals from a pre-existing nano reef that I took down. The rock had been cycled for nearly 4 months in 2 "Brute" garbage cans because I had to exchange the 120 a couple times. I did not use any of the rock from my nano, though I ultimately plan to add it.
Getting to the point, 3 of the rocks have already broken out in a bad case of green bubble algae...didn't take long, did it?
It doesn’t seem like Valonia, but lighter colored and more oblong in shape.
<Is a type of bubble algae, likely Boergesenia forbesii. I would remove the rocks from the system, remove the bubble algae manually and then rinse the rock well with system water outside of the tank.
More here:
http://www.reefkeeping.com/issues/2002-02/hcj/feature/index.php >
Now I know that a new tank will continue to have various algae species go through cycles for several months, and I have read everything on the site about bubble algae, but not sure if there is something I should do.
<Yes, see above.>
Should I remove these 3 rocks while I still might have a chance at eliminating these algae?
<Yes, I would even better if you can keep them outside of the system till you see how well the manually removal worked.>
Will it likely die back with time?
<Mmm, I would not chance it.>
I tested my water and Nitrates and Phosphates are zero, which is what I expected with so little livestock.
<Yes, but this doesn’t mean they aren't present. The excess nutrients may be utilize by such nuisance algae as it is produced and thus not detectable.>
I'm kind of bummed since I have been really going slowly, with a lot of planning to do this system right, and I already have this nuisance.
<Don't let this discourage you. Some nuisance algae is a normal part of the cycle. Continued patience will be rewarded. Take it slow.>
Any advice would be appreciated.
<Hope this helps.>
<Welcome, Mich>

Bubble Algae… Boergesenia forbesii 12/15/2007
Hi Crew,
<Hi Dave, Mich with you again.>
We exchanged some Emails a couple of weeks ago, and I would appreciate an opinion again.
To save you from re-reading the previous communications I will just say that I have a 1-month-old 120-gallon reef set up, with about 100 lbs of live rock that was cured for about 4 months in another container. The tank contains 4 LPS corals and 3 small fish from a "Nano" tank I took down when setting up this one. No live rock from the nano has been used. The tank is well maintained and both Phosphates and Nitrates read 0.
<There may be excess phosphate and nitrate in your system even though your tests are not detecting them, as your nuisance algae are likely taking them up, as quickly as they are produced.>
As sad as it seems (being melodramatic!) right from the get-go 2 of my rocks became totally infested with Boergesenia forbesii. Based on your advice, two times, one week apart I did a 10% water change and scrubbed, picked, and rinsed the crap out of those rocks before replacing them in the tank. I'm sure you won't be surprised that within days I could see loads of new bubbles starting to sprout once again. I can't imagine having to do this every week, so I just removed the two rocks and returned them to the LFS for credit, at a considerable $ loss!!!
<Mmm, sorry for you troubles. This algae does grow quickly, but I am surprised by how quickly it appears to be growing in your system.>
Today, I was looking closely at my rock, and lo and behold I see new, tiny little bubbles sprouting from rocks at the other end of the tank as well.
<Very possible.>
Some seem like Boergesenia forbesii again, but others look more spherical like either Macrophysa or Ventricosa (hard to tell since they're still small) and ANOTHER spot with grape Caulerpa!! AHHHH!
<Breath in... Breathe out... breath in... Breathe out...>
At this point I think that removing rock and manual cleaning will be a losing battle, not to mention a very laborious one. Starting over with new live rock seems risky as there's no guarantee I won't have the same problem again, not to mention very expensive.
<Yes, Is best to control the nutrients coming into your system.>
Is it possible to have a tank that is totally free of nuisance algae,
<Mmm, theoretically...>
in the same way you can have an "Ich free" tank unless you introduce it, or will it always be introduced on live rock and corals, even if only as spores?
<Spores can be present in the air even...>
Am I making a bigger deal of this than I should, and fretting over nothing?
<Is my impression, but I'm not looking at your tank... So if it is completely covered in green and limiting the growth of your corals you have a problem... If it is only an occasional patch here or there I would be more concerned about controlling your nutrients. Much more here:
http://www.wetwebmedia.com/maralgae.htm  >
I wonder if the way to go in the future is to set up a reef with base/dead rock, and then seed the tank with 1 or 2 cured pieces that have been carefully quarantined until confident that no algae is sprouting!?
<Some people have found this preferable, but it would not be my first choice. If you go this route, Marco rocks has some really beautiful dead rock.>
I have read everything I can on your site and on ReefCentral about how others have dealt with this problem, and it seems discouraging. Any advice at this point would be appreciated.
<Please see above.>
Thanks again,
<Welcome and sorry for the long delay, Mich>

Bubble algae: Boergesenia forbesii -9/17/07
<Hi Ken>
I have a colony of what I believe is Boergesenia forbesii. <Okay> I searched WWM
and can't find any citations, hence this question. The items in question are attached to a small piece of rock on the floor of my reef tank. <Good, sounds easily accessible.> They are pale green, translucent, tubular (some with slight bulge in the middle) and are 1+ inches in length. <The individual cells/”bubbles” of this specie can get up to around 2 inches in length and have an almost club-like, or teardrop, shape to them.> Are they bad actors like bubble algae? <Heeee! “To be, or not to be - a pox upon the aquarium: that, is the question.” Sorry, couldn’t resist <gr>.> They are interesting to look at <Agreed> but I would remove them if there is a risk of proliferation. <While this specie doesn’t seem to be as invasive as Valonia or Ventricaria, it’s still a bubble-type algae and I would remove it. Interestingly enough, a synonym for Boergesenia forbesii is Valonia forbesii. For me, it’s the old standard: “When in doubt, take it out”. I would extract the rock from the tank, and manually remove the cells – trying not to burst them. Please see this link for more information re: http://www.reefkeeping.com/issues/2002-02/hcj/feature/index.php>
<You're most welcome! -Lynn>

Persistent green stuff...help! Bubble Algae  4/26/07 Hey guys,
I've been using your site for years and I thoroughly appreciate all of your help,
<Very nice to hear, you are welcome and thank you.>
the results of which have been a moderately successful 50 gallon saltwater tank with live rock and inverts.
<Well lets see what we can do to change that "moderate" rating to "highly" successful.>
I am writing because ever since I placed a yellow Fiji leather coral in my tank along with the rock it was attached to, the
algae/green stuff that was on that rock has been slowly taking over my tank. Its been about two years now.
<It looks to be Green Bubble Algae; Ventricaria Ventricosa.>
The green algae/stuff is short and crunchy and very hard to remove.
Also, it crowds out other living things on the rock, such as my xenia.
<Yes this creature can outcompete the best cnidarians in the "space-wars.">
When I remove it manually it does not take long to re-grow, gets stuck in my intakes and never seems to be fully removed in the first place because it clings to the rock so well.
<And the spores, seedlings..."parts... from manual cleaning tend to find there way back to the rock.>
I was wondering if you could identify it for me from the attached pictures
<See above ^^ .>
and whether you could tell me any sort of solution (hopefully a natural grazer of this pest green stuff!).
<I have a few questions for you as well;
*Do you test the water; if so what are the parameters (particularly nitrates and phosphates)?
*What is your source water?
*How is the water flow in the aquarium?
*What is your water change regime?
*What type/how much lighting, how old are the bulbs?
Sorry for all the questions but they will help me to give you a better plan of attack. In the meantime you did mention natural predators. Many aquarists have had success with employing emerald crabs, however the crabs are opportunistic omnivores and that presents an issue itself.  Other have recommended employing Zebrasoma sp.; tangs but they grow quite large and often times there are territorial. compatibility issues with pre-existing tank mates...or the tank is simply too small. Check out these articles/FAQ's as well:
http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm .>
Any help or suggestion would be much appreciated.  I just really hope
I do not have to buy all new live rock!
<No I don't think that will be necessary.>
Thanks very much,
<Of course.>
<Adam J.>

Re: Persistent green stuff...help! Re: Bubble Algae – 04/30/07
Sounds like I need some crabs.
<Well ....oh you don't mean those kinds crabs...never mind. Seriously though do look into the pros and cons of utilizing crabs in a mixed reef tank, there are som cons....I'm sure you have heard the phrase opportunistic omnivore.>
Here is the info requested,
and again, thanks you so much for your help.
<Of course...>
I do not know what I would do otherwise.
My Nitrates are always at zero;
<Okay that's good.>
Am not sure what my phosphates are at this time because I am out of that test solution and failed to write down that info in my tank diary (and that's probably gonna be the source of my problem!).
<Could be, is a prime culprit.>
My source water is tap water form NY.
<Hmmm....I would test this as well.>
Water flow is excellent.
I have two large powerheads running, a skimmer, and a Eheim filter.
<A canister?>
I change a little over 5 gallons every week (46 gal tank).
My lighting is two 175 MH (12 hours)
<Too long.>
and at night two 96w actinic compact fluorescents (3hrs) (one hour of overlap between the two) (all bulbs about a bit more than a year old).
<Time to change them out, especially the PC's.>
I hope this helps, and sorry for being a bad fish daddy- not knowing my phosphates!
<No worries but at your earliest convenience I would test them.>
But thanks again, Adam.  Your efforts and time make a real difference.
<Thank you my friend.>
<Adam J.>

Aiptasia, PLUS bubble algae  4/21/07
Hey guys, couple of problems here.
<Let’s sort it Batman>
I've got Aiptasia (right now just one that I can see, but what's the chance that its the only one in my 55 gallon?)  Also, I’ve got bubble algae. I forget what kind it is, but one is the big clump of tiny dark green bubbles, and the other kind is what I’ve read to resemble "bite sized green hotdogs". These "hotdogs" are still pretty small, but spreading, the same as the darker ones.
<Likely the infamous bubble algae Valonia and possibly Neomeris annulata for the second ID>
Anyway, I know that peppermint shrimp can take care of the Aiptasia, and an emerald Mithrax crab can handle the bubble algae. My question is, will the crab and shrimp coexist in my 55?
<They will probably coexist, however I think the excess nutrients probably present to allow this recent up growing of Nitrate loving organisms needs addressing without forcing upon animals. I believe that fish/inverts should not be bought to cover over the problem. If these animals keep on top of these problems, then your water quality could deteriorate without these indicators. Also there is no guarantee what so ever that these animals will work; especially the peppermint shrimp>
I also have a pretty small blue damsel, a lawnmower blenny, 3 tiny mollies, 2 blue leg hermits, and a snail of some sort (about the size of the blue legs). If all of these will co exist (I’m not really worried about the mollies
<No animal is disposable because of human desire>
would getting 2 Emeralds and 2 Peppermint's be pushing the overload limit? In the future, I plan on having 2 Ocellaris clown's, and 3 to 5 reef chromis, so this may or may not add to the equation (in both overload AND compatibility)..
<In terms of bio-load and compatibility, this selection should do fine in a tank this size. With crabs there is always a area of risk, this comes with such a successful and adaptive omnivorous diet. By all means add these but check and continue checking nutrient levels as the source of your problems>
Thanks much for your help!
<Pleasure, Olly>

Bubble algae problem  -01/12/2006
After I introduced some new live rock into my tank a ton of bubble algae have been overtaking it. Previously no bubble existed in my tank and even at the beginning of this problem the few clusters of algae developing were retrieved easily by hand (not braking them but always one or two explodes within the cluster).
<Best to siphon out... with a small diameter bit of rigid tubing attached to a length of larger flexible>
But now there are bubbles all over the rocks and not in clusters but also single ones. I have no other problems with algae, neither Cyanobacteria, diatoms or hair algae. I have a refugium with biosediment and 4 mangrove plants and Caulerpa in it and when tests for phosphates and nitrates are performed only phosphate gives a reading of less than 0.2ppm (which is the minimum of the aquarium pharmaceutical test range). Nitrate reads 0ppm.
<May well be that these essential nutrients are being scavenged, not in solution...>
A keep a record since I began my tank more that 1 1/2 years ago of all my readings all are consistent (even when changing test kits brands throughout that period of time the results are similar or identical). What will be my options here, introducing some kind of fish or invertebrate that feeds on it or water parameters must be adjusted?
<More the latter... I would switch out the Caulerpa for other algae (groups... Reds), maybe try the "Kalkwasser Trick"...>
Just to give you another thing that is maybe marginal in my parameters is alkalinity which is at 7dKH. Calcium is between 450-500,
<I would raise former, drop the latter...>
ph is 8.2(the refugium is lighted on a reverse cycle so I think this is or should be somewhat stable) and ammonia and nitrite are 0 according to my test kits (red sea and aquarium systems). Thanks!
<These are covered on WWM. Bob Fenner>
Re: Bubble algae problem... the Google search tool   1/13/06

Sorry for my ignorance but, what is the Kalkwasser Trick or where did I find this explanation?
<Sorry re... to expedite matters, let's give you "fishing" instead of a/the fish: use the Google search tool on WWM, view the cached version with these two words...>
Thanks for your recommendations. Actually I'm using Kent super buffer dKH in an attempt to bring the Alk up to around 10 or 11 that is where I previously kept before started using a Coralife 2 part buffer and calcium additive. Since using that product the Alk never raised from 7 even when I stopped using the calcium part of the system.
<Thank you for this data. Bob Fenner>

Bubble algae 8/29/05
Hi Whoever is there today,
<Howdy Sharon>
Please can you give some advice. I've scoured the website and can't seem to find an answer.
I have one little collection (about 8 little bubbles) of what I think is black bubble algae on one of my live rocks. It has been there for several weeks now and hasn't spread as far as I can see; the bubbles are just getting bigger. This is on one of my biggest rocks and there is no chance of taking the whole thing out of the water.
There is no other algae problem in my tank so I don't think there is a nutrient problem in the water.
Should I try and scrape the bubbles off? I have been reluctant to do anything so far in case that makes it spread somewhere else.
What do you suggest I do?
<I would try rubbing it with the end of your siphon during water changes... if it doesn't all come off, no big deal... with time, likely it will go of its own accord. Bob Fenner>
Many thanks,

Bubble Algae, Dictyosphaeria versluysii? 7/26/05
I've got some very slow growing bubble algae on a rock in a mixed reef aquarium. It looks like Dictyosphaeria versluysii, but I am certainly not a taxonomist, so I don't know for sure. "Bubbles" are very small, about a millimeter or less in diameter, and form very tight, compact green to blue-green colonies. It seems to do very well where there is vigorous water flow and it's quite resistant to a toothbrush on the end of a siphon tube. I have read some info that suggests, unlike Valonia, one should leave D. v. alone and enjoy it. What is your opinion, should I make an attempt to scrub it off the rocks if it is in fact Dictyosphaeria versluysii? Thanks, George
<Mmm, some folks over-react... usually self-limiting... I wouldn't be overly concerned. You can search on WWM re the genus... Bob Fenner>

Valonia and Mithrax (3/13/04)
  Greetings and a huge thanks to all you in the crew for providing me and others such invaluable guidance, in the year I've been reading the posts daily, my tanks are UNBELIEVABLE!! Everything is growing and thriving at exponential rates. <Good to hear.> Which brings me to my question. I am getting a ton of green bubbles popping up all over the live rock in my 40 gal reef. I know nutrient control is the issue, and I've greatly cut back my feedings, tweaked my Remora for optimal skimming, and do 2 gallon water changes twice a week religiously. I have been hearing more negative than positive comments lately about Mithrax crabs being destructive and difficult at best to remove when larger, so I'm hesitant at putting one (or any crab) in my system. <Wise to be cautious.>
  Additionally, it seems to be the general consensus that in trying to remove Valonia (various species) one has to be very careful not to puncture the "bubble" so as to not release spores into the water column. My question is: if I do put a Mithrax crab in, isn't that exactly what they do, puncture the algae, and consume it (if they have a liking for it) so why does it not spread under these circumstances? <Some risk I suppose, but does seem to work for some.>
What are your thoughts on just slicing the bubbles open as soon as I see them appear (i.e. real small) with a razor blade? <Vacuuming them off would probably do better. Anthony & Bob's book (Reef Invertebrates) recommends attaching a toothbrush to the end of the siphon. That way you can suck up spores as the bubble bursts. Another option would be to remove rocks that are heavily infested and scrub all the Valonia off in a bucket of saltwater before returning the rock to the tank.> Doing this persistently, would the situation get worse, or better, not allowing any to reach a size greater than 1/8th inch? <I would worry a bit about making it spread more. Your nutrient control approach is vitally important to successfully controlling this algae.> I was thinking doing this, the skimmer and other inhabitants would consume/remove any spores that may get released.. <Will help to some degree.>
  Other than that my tank is looking awesome, and in less than 3 months running, the ENTIRE back face of the tank is totally encrusted in what appears to be at least 4 colors of coralline algae, and the fauna is exploding! ((I chose not to add any fish until 6 mo. to a year) <Your patience will be richly rewarded. Keep up the good work. Choose your fish carefully and quarantine them.>
Thanks again for all you've done to assist! keep up the good work.
Blair <A pleasure. Hope this helps.>

Dear Crew,
I really appreciate your site and find it very informative. I am always amazed at the boneheads that jump all over somebody when they don't agree with the advice they receive. That being said, I have a question about Valonia.
A few years ago I had a few Valonia in my 65 gallon tank, and emerald crab took care of the problem and the tank showed no signs of Valonia. After a tank crash that I think was caused by the death of an orange tree sponge, the crab died. The Valonia has gradually increased to the point where I need to take more aggressive measures to rid my tank of this nuisance. I have read ALL the information on Wet Web Media and its seems that the best answer is to get another emerald crab. 
I have two questions.
First, other than the usual nitrate reductions advice is there anything else I can do?
<Do not overstock the tank, reduce nutrients.>
Second, I am concerned about my other livestock getting munched by the crab if I get it. I have two peppermint shrimp, a scooter blenny, a six line wrasse, a purple tang, and two percula clownfish. I am very worried that the peppermint shrimp and the blenny are potential victims. How threatened are they? 
<Not to worry. I have an emerald crab sharing the same tank as two cleaner shrimp and four small fish. Haven't had a problem yet.>
Any other ideas that might be helpful? 
<Get another emerald>
Thanks for any advice you can provide. 
<James (Salty Dog)>

Bubble algae v Coralline
Hi all,
I have noticed that some of my bubble algae (I kind of just let it ride, doesn't seem to hurt anything) has coralline growing on it. Will the coralline eventually kill the bubble algae? If so the seems like a pretty easy way to control it. Anyone that has had this battle happen please let me know who wins.
<Hmm, interesting question.  I don't think either really 'wins'.  The coralline doesn't seem to hurt the bubble algae, and vice versa.  The bubble can usually still get large and reproduce even with coralline on it.  I have had tanks with this type of situation and, left unchecked, the bubble algae will spread rampantly.>

Not-So Tiny Bubbles.. Where's Don Ho When Ya Need Him?
>Hi Crew,
>I have a small leather coral "frag" growing on a Aragocrete plug. On the top of the plug there is some bubble algae (Valonia?) growing. I have taken the plug out of the tank and scraped of the bubbles, but they return. How can I safely remove the algae without harming the coral?  Thank you for any ideas you may have.
>>That's a tough one, and I'm inclined to suggest actually chipping away the bit of the plug where it's growing.  That, or consider the animals that eat it (the dreaded Mithrax crab).  Don't burst the bubbles, I believe this spreads them.  Also, please use our Google bar at the bottom of our home page and search Valonia.  Marina

Bubble Trouble?
Dear Sirs:  I have set up my first reef tank 5 months ago and it is doing well. A few weeks ago I purchased some more live rock for my tank and I noticed recently something that looks like pea size green eggs, there almost the size of a small vitamin capsule, I don't know if it's good or bad.
<You have Valonia, or "bubble algae". While they are not harmful per se, they can multiple rapidly and create problems for other, more desirable species. You can remove them by carefully prying them up and siphoning them out, taking care not to rupture the membrane in the process, as this will result in the release of products which will lead to more of them appearing throughout your tank!>
I am concerned because they seem to be multiplying slowly unless it's just my imagination.
<Not your imagination, they can multiply rapidly under favorable conditions! They can be persistent and maddening if you hate looking at them, like a lot of people! Unfortunately, there are no herbivorous fishes which regularly consume them. Some people employ various small crabs to eat them, with mixed results (some end up munching on corals, too). If it were me, I'd try to siphon as many as I could out. Keep up your high water quality and good husbandry techniques, and you should be able to keep them in check.>
Could you please give me your input? I am so thankful for experienced people like you.  Connie
<And I'm so glad to help people like you, Connie! Good luck!  Scott F.>

SeaBAY (the club in SF, not the anemone)
Dear Bob and Anthony:
I belong to an organization called SeaBAY and we meet on alternate months here in the SF Bay area.  What would it take to get you fellas out here for a visit?
<Mmm, we've been out there... this year. Anthony will come out most anytime... for hugs and sunshine.>
>Also, I have something that looks just like a grape (sea grape?) growing on my L.R.  -- is this okay for the fish if they eat it or should I remove?
<I'd leave as is... Please see here: http://www.wetwebmedia.com/greenalg.htm see what you have down towards the bottom? Usually not too much of a pest (not me or Anthony, these algae). You can take out the rock, scrub it off later if you'd like. Bob F>
Your ardent fan, Connie C.

SeaBAY (great San Francisco/Bay area Aquarium Club)
Dear Bob and Anthony:
<cheers, dear>
I belong to an organization called SeaBAY and we meet on alternate months here in the SF Bay area.  What would it take to get you fellas out here for a visit?
<for Bob it is usually beer... I'm partial instead to those flaky little pastries called "lady locks/fingers". Ha! But seriously... ahh... it usually takes... an invitation :) The requirements would simply be airfare and a place to sleep and time in the schedule. We can feed ourselves and will be sure to decline any remuneration (any such monies belong in the clubs coiffeurs!). <<Antoine, you're cracking me up... am sure they're moolah should stay in coffers, not their hairdressers!>>That's it my friend... the cost of travel. Bob has a copy of this in his folder and will respond with some indication of his schedule/ability. For me... please look over the schedule here to see what works best for the club: http://www.readingtrees.com/meet_the_authors.htm
February is a possibility, else it may be best after June.>
Also, I have something that looks just like a grape (sea grape?) growing on my L.R.  -- is this okay for the fish if they eat it or should I remove? Your ardent fan, Connie C.
<no worries at all... this likely algae will be quite fine for them to eat. If they do not, however... be careful that it does not grow into wildly. (even some decorative algae (C. racemosa) can be a nuisance... or this may even simply be Valonia type). With kind regards, Anthony>

Mithrax crabs
Dear Bob:
First of all I have to tell you that your book is my bible. I keep it near my 60 gallon saltwater reef tank and as a result it looks pretty dog-eared. (It's had it share of salt water). I had a bad case of bubble algae and the fish store recommended Mithrax crabs.
<Very typical.>
My husband came home with one really full-sized crab and he couldn't do the job, so we got a bunch more, most of them small. I have four false Percula clowns, 1 pygmy angel and 1 royal Gramma, also a bunch of small crabs. I have a feeling I am missing some crabs, and now am frightened that I'll lose one of my clowns. They are all juveniles and one in particular is not a fast swimmer. The Mithrax crabs have done a good job but I now realize I have too many and would like to get rid of the largest ones and keep maybe one or two of the small ones. Question: How do I accomplish this without emptying out the tank.
<I would try to trap they. Use the Google search engine on www.WetWebMedia.com looking for traps, mantis shrimp, etc. We have discussed several commercial and a few DIY traps.>
Is it my fertile imagination that one night soon I'll lose a clown to one of these crabs?
<No, a very real possibility.>
And should I have any at all.
<One to two small ones.>
If I got a tang would that crowd my tank and would he eat the bubbles?
<Depends on species, but probably yes and no respectively.>
This is early Monday a.m. in California. I don't know where you are but I sure hope you check your email often. I think we need to take action within the next few days.
PS We put some ROWAphos in our pump along with the carbon filters and it looks as if it's helping with the phosphate level, which was never sky-high as I have a protein skimmer and conscientious about cleaning the substrate.
Thanks so much for your help. Connie Cavan
<Good luck! -Steven Pro>

Bubble algae
I have some concerns about the bubble algae in my tank. The tank is a 120 reef with fish and corals. The fish I have are: hippo tang, flame angel, Copperband butterfly, Foxface, royal Gramma, blue damsel, scooter blenny, and an o. clown. I have a couple emerald crabs too. I don't have a lot of bubble algae bubbles, but the three or four I usually do have get really big. The last two I picked off were twice the size of a golf ball. This has been going on for about six months. The reason I am worried about the algae is because I was at the LFS looking for corals and their tanks are covered with bubbles. How can I tell if the algae is going to go into sexual reproduction? 
<no conspicuous outward appearance. But don't wait for it. You can tie a toothbrush (plastic zip/cable tie) to the end of a siphon so that the brush extends forward slightly. You can then scrub and siphon simultaneously so that "spores" are not spread when you rupture the bubbles>
Do you think the fish I have help with bubble algae control? 
<none at all likely>
I've also read about Sailfin tangs liking it. 
<yep... and Naso tangs too>
Thanks! -Becky
<best regards, Anthony>

Silver Bubble
We've observed a couple of silver bubbles developing on the live rocks in the reef tank over the past several weeks. One of them has almost reached the size of a golf ball. They are not soft or pliable, but hard. What are these? Should they be removed?
<Sounds like a kind of bubble algae, maybe Valonia ventricosa. Most consider them to be a pest, but I am not bothered by them. If you do remove them, do not break them open. Try to get them to pop off.>
Thanks for your help. April
<You are welcome. -Steven Pro>

Valonia Problems?
I seem to be close to having an outbreak of bubble algae. All water parameters are fine (pH - 8.2, Temp - 79, Nitrates - 0.00, Alk - 3.2, etc.).
I noticed a small amount of bubble algae on my live rock right after I placed it in the tank about 4-5 months ago, but recently it seems to be spreading everywhere. <<that is the nature of most any algae, given the right conditions>> I have green algae growing on the glass (front and sides) and a pretty good growth of red coralline algae growing on the back of the tank, but none seem to be spreading at the rate of the bubble algae. <<yes, very successful life form>> Are there any inverts or fish that feed on the bubble algae. <<Mithrax crab comes to mind.>> The algae is not a real problem yet, as I only have 3 small soft corals in the tank, but I've read that the bubble algae can choke out corals over time. Any help would be greatly appreciated as usual.
<<do read through the following pages: http://www.wetwebmedia.com/greenalg.htm - think perhaps about manual [with your hands] removal>>
Thank You,
Phil in San Diego
<<Cheers, J -- >>

My Valonia
Dear Bob,
Since the 20 gallon refugium got loaded with Caulerpa and adding de-ionization to the R/O, I have had no visible micro algae in the show tank. Several weeks ago a bubble of Valonia appeared pushing out from a hole in a piece of live rock. It looks exactly like the your photo of Valonia. Now the colony is about 1 1/2 inch in diameter, a beautiful translucent color with growths of pink coralline algae dotting it. It is hard, like acrylic, to the touch.
I have seen questions on your site indicating that Valonia can be a problem, hard to get rid of, etc. My question is, should I get rid of this big sphere before it multiplies into a problem? (I envision it bursting and spreading little bubbles all over.) I like how it looks, colorful and interesting. In 15 months since I began creating this reef, this is the first "bubble algae" I have seen. Tests show no detectable nitrates, phosphates, or silicates. Tangs, crabs, and shrimp ignore the bubble.
<No need to rush... you can remove the rock involved, do a bit of scrubbing later if this algae becomes a pest. I would leave, enjoy it. Bob Fenner>

Bubble algae follow up
Hi Anthony, Thanks for your prompt response!
<my pleasure!>
Yes, our pH is about 8.2 (as you suspected!) We are now trying to increase this, however, all the products available (for marine systems) that we have looked at for increasing pH seem to only raise pH to 8.2. We have seen nothing available to make it higher. Have you any suggestions?
<yes...try the buffering part (only at first) of a two part calcium mix. For something simpler and less expensive... you can very slowly (small amounts) and carefully add a bit of baking soda daily until you reach your targeted pH and then assess the buffering ability of the system by seeing how long the pH stays up>
Also, am I right in thinking that a higher pH affects ammonia levels? 
<yes, but all moot... and dangerous enough at the higher end that we must invariably work on for marine aquaria> 
It all seems to be a bit of a juggling act! Meantime, our newly purchased algae blenny seems to be really tucking into the algae.
Thanks again for all your help. This website is a godsend for us "marines"!
<thank you! and keep learning and growing... and teach when you can. Share the knowledge. Anthony>

Mithrax Crab / Bubble Algae Question
About a month ago, I wrote to you about a bubble algae problem I was beginning to have. Well, now it is a huge problem. I have been trying to remove it by hand, but this seems to be a losing battle. In your reply to my earlier e-mail you mentioned that Mithrax sculptus, the Green/Emerald Crab is known to eat bubble algae so I'm thinking of adding one (or more) to my tank. My questions are. a) will it bother the banded coral shrimp and 2 common cleaner shrimps I have and b) will it bother / eat any corals or clams?? Also, any other ideas for eliminating this pesky algae would be greatly appreciated. Thanks for your help again!
Phil in San Diego
<Very rare to have Mithrax crabs bother other crustaceans, corals, or clams... try one per fifty gallons or so... and start small... like one inch across the carapace in size. Bob Fenner>

Bubble Algae
<<JasonC here, Bob is away diving.>>
I noticed some bubble algae has developed in my tank (58 gal). I purchased two Emerald Crabs hoping to get rid of or control the algae.
They have been in the tank only one day... and have been eating something... micro algae or poop or whatever... not the bubble algae
though. Should I be more patient? <<yes.>> I noticed both crabs eating something and bubble algae was almost touching them and they ignored it... which burst my bubble. I hear these crabs are great for algae reduction... esp. bubble. If not the crabs, how do I get rid of it? <<with your bare hand(s) - just gently grab as close to the base as possible and wiggle like a loose tooth, it will come out, and if it pops, just take it out of the tank quick. No harm should come of it - just cleaned up a small patch myself this way last night. Sometimes you will get the odd small, single bubble a couple of weeks from now, but your crabs will probably nab that.>>
Have a good day!
<<You as well. Cheers, J -- >>

Mr. Bob Fenner
I forgot to ask your opinion about a algae problem with Valonia that is growing too much in my tank. Could I use a needle to empty the spheres one by one?
<I would not>
Or this practice will contribute for a major dissemination of the algae?
<Possibly... or the death of other life...>
Inject something like hot water or small portions of acetic acid?
<No my friend. Please read here: http://www.wetwebmedia.com/algaeconMar.htm
and the associated FAQs beyond. Bob Fenner>
Thank you very much
Fl?io Ribeiro

Bubble Algae
First, thanks for taking my e-mail. I've read all kinds of articles and all kinds of postings concerning how to deal with bubble algae. So far I have not found a common thread. Some talk about emerald crabs, some talk about fish, some talk about throwing your rock out.
<Hmm, maybe scrubbing the rock... there are many, though no one definitive control approach>
I would prefer not to throw out my rock. I have a very bad outbreak of bubble algae in my 55gal reef tank. I have 2 emerald crabs, but they don't seem to be doing that good of a job. I've taken some of the rocks out and either scrubbed the bubbles off with a brush or pulled the bubbles off with a pair of needle nose pliers. I then washed them in fresh water. I did that with a soft coral on one of these rocks and the coral does not seem to be doing that well. 
<I'll bet>
I think I'm going to try and clean all rocks that have no corals attached to them.
Please let me know what you think.
Gary G. Gentles
Avon, IN
<Please take a read through the "Algae" and "Algae Control" parts of our site: www.WetWebMedia.com... one avenue you don't mention, but that I would definitely try is culturing other macro-algae in the same tank or an attached sump... Read about this approach on the WWM site. Bob Fenner>

More Baloney, make that Valonia
Thanks for your wonderful book and the Q&A. Both very helpful.
I have a 70 gal reef/community tank with 90 lbs of Fiji live rock which is about 3 months old. I have noticed several small iridescent, gun-metal gray "bubbles" which formed on one rock. When I first noticed them they were about the size of a ball bearing, but are now about the size of a marble. They look almost like jellyfish. What are they?
Should I be concerned about them, remove them? Thanks.
< Thank you for writing. The bubble like objects you're seeing are likely Valonia, aka bubble or pearl algae, a multi-cellular aggregation of one of a few species of Green Algae. They are not a problem per se, unless they become very numerous. There are some crabs, and occasionally a fish that will eat them. For small numbers of little colonies, I'd try vacuuming them away (like with a small siphon) and not worry.
Bob Fenner >

Valonia, Valonia, Valonia, oh, oh, oh... repeat
I have a 70 gal reef/community tank with 90 lbs of Fiji live rock which is about 3 months old. I have noticed several small iridescent, gun-metal gray "bubbles" which formed on one rock. When I first noticed them they were about the size of a ball bearing, but are now about the size of a marble. They look almost like jellyfish. What are they?
Should I be concerned about them, remove them? Thanks.
< Thank you for writing. The bubble like objects you're seeing are likely Valonia, aka bubble or pearl algae, a multi-cellular aggregation of one of a few species of Green Algae. They are not a problem per se, unless they become very numerous. There are some crabs, and occasionally a fish that will eat them. For small numbers of little colonies, I'd try vacuuming them away (like with a small siphon) and not worry.
Bob Fenner>

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