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FAQs about Caulerpa Algae 3

Related Articles: Caulerpas by Bob Fenner, A closer look at Caulerpa - Common aquarium species and their care by Adam Jenkins, Embracing Biodiversity, Green Algae By Mark E. Evans, 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: Caulerpa Algae 1, Caulerpa 2, Caulerpa 4, Caulerpa 5, Caulerpa Identification, Caulerpa Behavior, Caulerpa Compatibility/Control, Caulerpa  Selection, Caulerpa Systems, Caulerpa Nutrition, Caulerpa Disease, Caulerpa Reproduction/Propagation, 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

Caulerpa racemosa (not evil in small doses). 

Grape Caulerpa... the Worst - 7/14/03 Please help me.  I have a long-established tank (10-plus years).  We recently did an overhaul (redecorated) and added some more live rock.  Some of it had some pretty grape Caulerpa on it.  However, now the Caulerpa has gone crazy, and I am harvesting about one cup a week of the stuff, as it is crawling all over my corals, even trying to climb up my magnifica anemone!   <Caulerpa racemosa is indeed one of the most invasive and noxious (as in toxic and unpalatable) species to be found> I can't get rid of it.  Someone told me to buy a mustard tang, and that would it Never touched a bite!   <not surprising... this is truly one of the most noxious algae. Herbivory by fishes is rather hit or miss.> Do you know anything that will gobble my Caulerpa?   <you might try an Elysia crispata (lettuce nudibranch). Still... I'm sure it will outgrow even several such nudibranchs on patrol. Manual extraction may be necessary. Do consult our archives and FAQs at www.wetwebmedia.com for much more info (pros and cons) to these algae > thanks for you help. <best regards, Anthony>

Caulerpaceae Greetings Bob, I must commend you and the others for putting together such a extensive and informative site. I have recently read your article GREEN ALGAE OF THE FAMILY CAULERPACEAE. In the first paragraph you mention that Caulerpa has the largest (I assume by volume) cell in the algae order. I am under the impression that this excludes Chara the freshwater algae. Correct me if I am wrong. Thanks, <I do think (and this is not an original assessment... as are likely any!) that Caulerpa are the largest single cell organisms (even more than ostrich eggs) in the world including (have removed a bunch of the green algae genus) Chara.> Devoted fan of your work Nathan LaVoy B.S. Biology <Be chatting, Bob Fenner>

Caulerpa racemosa predator 6/25/03 Dear crew member <cheers, my friend> Have enjoyed and benefited from this site for years - from the times when Bob was handling it alone. <outstanding... and thanks kindly. Really wonderful for us all/the hobby to see it grow <G>> This is my 1st message sent. My 70 gal reef has been up & running for 5 years. I have about 100 lbs of live rock, 1/2" to 1" sand substrate, 2 tridacnid maximas, a branching frogspawn, a hairy leather, a colt, and various polyps and mushrooms. I have a percula clown, a Banggai cardinal, and a chevron tang (4"). The system is stable - it has been over 2 years since I have introduced anything. My problem is Caulerpa racemosa. <heehee... rat weed. And one of the most legitimately noxious of all Caulerpas. My least fav> Once a month or so I harvest it by hand. <be sure to thin (pull fronds) and not tear or cut> I skim aggressively, use activated carbon, perform monthly 15% water changes, feed the fish twice a week rotating frozen Mysis, blood worms, and krill. <excellent> the chevron will rasp at the almost non-existent microalgae on the rocks and aquarium glass, but will not touch the racemosa. <correct... it is quite noxious to many/most fishes> I think my fish load is light enough to introduce another, but I need a big time algae eater, and I'm concerned about mixing tangs. <not a great idea or even likely to work> Is there a prodigious macro algae eater I can add to this group, or should I consider trading in the chevron in favor of a different tang? Thanks for you time and consideration.   Larry <seek instead some of the algae grazing sea slugs of the genus Elysia =Tridachiella... they are cheap, hardy (one of the few Opistos that it is true about)... and certain species are voracious Caulerpa eaters. They harvest their chloroplasts like the nudibranchs harvest cnidarian stinging cells. Best regards, Anthony>

Caulerpa lighting 6/22/03 I have also read many things about lighting. Some say lights on at night and some say lights on 24/7. Can I use this stuff with lights on 12 hours a day or should I leave them on 24/7. <I would recommend lights on 12 hours per day on an opposite photoperiod to the main display with hopes for assisting pH stability for it. Else... the 24 hr constant light cycle is an attempt to keep the algae in stasis with the hope of preventing a potentially dangerous or devastating act of sexual reproduction/vegetative fission from this noxious species. There are pros and cons to both. I would still suggest you consider alternate species of macroalgae for stability and safety issues. Best regards, Anthony>

Caulerpa Gone Wild! Good morning, <Hello there! Scott F. with you today!> Could you please give me a bit of advice on how to reduce the amount of Caulerpa in my tank?  When I purchased it I tried to keep it localized in the tank, but it has gradually spread and is causing me to move my corals.  It is just impossible to remove it by hand effectively though I am trying. <It's tough! The fronds tend to put down holdfasts that make removal without breaking them very difficult>   It is a 55g tank and is generally causing me few problems, water quality is fine and fish and corals are healthy.  What would be an appropriate macro-algae eater?  My yellow tang has a nibble, but I don't think the red legged hermits touch it. Many thanks, Peter Harris <Well, Peter, I'd like to recommend a "natural" approach, such as another tang (like a Sailfin tang- which, in my experience, is a macroalgae-eating "machine") or rabbit fish- but I think that your tank could not comfortably accommodate one at this point. They simply get too large. I'd stick to a "low tech" approach, unfortunately- which means manually extracting the stuff! Try to take care when extracting the Caulerpa, as ripping the fronds can leach some potentially toxic substances into the water. The other thing that you could do is try to remove the rocks that the Caulerpa has attached to, and rip away at the stuff once it's outside the tank. Although I am not a big fan of Caulerpa (for a lot of reasons- some of which you are now aware!), it may be worth simply keeping contained as much as possible. Remove all "adventurous" holdfasts that journey out of your "designated Caulerpa zone". Easier said than done, but it may be infinitely more simple than removing your rocks, etc. to extract the stuff. Good luck! Regards, Scott F> temp 25 sg 1.024 ph 8.4 at 8pm lights on nitrates < 10ppm phos is hard to measure, just detectable with my kit calcium 300ppm (I am trying to raise this) I run a hang on skimmer, canister filter, 70kg live rock, no sand.  I have a yellow tang, one purple Dottyback, 3 green Chromis, 1 blood shrimp, 1 red starfish, 4 turbo snails, 4 red legged hermits.

Re: sea grape Hello to All! <All of PF with you here tonight, Jason> I have a refugium that I've been wanting to put some macro-algae in.  One of my local fish stores have now started selling sea grape by the pound.  Would placing this in my gravity fed refugium be beneficial to my tank?  Its a 65gal.  75lbs of LR; toadstool, xenia and button polyps are my only inhabitants.. <Well, it sounds like they're selling Caulerpa racemosa. I'm not fond of Caulerpa as it made quite an effort to take over my tank, strangling off my xenia before I got it under control (thanks to a hungry tang). I prefer Chaetomorpha to Caulerpa - it doesn't crash, it doesn't try to take over the tank, and it doesn't produce allelopathic chemicals - all major pluses in my book. Check w/your LFS and see if they'll order it for you. OTOH, if you have a tang (or other herbivorous fish such as a rabbit fish) then you could try the Caulerpa and feed it to the fish. Personally though, I'm much happier with Chaetomorpha.> thanks, Jason...Surfs Up! <It usually is on the coast I live on, but not much fun to play in the Oregon surf, to cold for my blood. ; ) >

Simple question about Caulerpa Dear Dr. Fenner, According to the PBS program, Nova, about the growing threat of Caulerpa in the Mediterranean, native sea urchins would rather starve to death than consume Caulerpa. Your article on the web  refers to a species of sea urchin that has a voracious appetite for Caulerpa. Could this species be useful in the control of this worldwide pest? <Mmm, better perhaps to look for local species that might consume or prove deadly infectious to non-indigenous species... and culture, disperse them than introduce another non-indigenous species> Would it survive in the Mediterranean, or would there be any risk to its introduction there?  I hope you have the time to respond to this question. <I fear the latter if it was able to live there. Recorded history is replete with examples of approaches to bio-control... most have shown that being "patient" (just waiting) is the best option... predators, other rate-limiting factors arise in time to control all populations... including our own. Bob Fenner> Sincerely, Jon Michnovicz M.D., Ph.D. The Foundation for Preventive Oncology

Foam on The Macro I have yet another question for the experts! I have a refugium with various macro algae's mostly grape and feather Caulerpa , I harvest weekly and the lights are on 24/7. <Good nutrient export if you harvest weekly!> I have noticed that on the water surface in the refugium a white foam that collects around the algae, the surface is agitated by the water flow from the main tank.  Any idea on what this is and what needs to be done if anything. As always your opinions are appreciated. Mike Winston <Hey, Mike- I know exactly what you're talking about here...I've seen it too. Sounds like some organic foam, possibly analogous to "skimmate" from protein skimmer effluent (but not as concentrated). I'd remove it by using a net, or a piece of paper towel placed on the surface of the water in the refugium, then quickly removed. Hope this helps! regards, Scott F.>

Re: red Caulerpa algae Thanks for the great web site, I have told everyone about you guys!  I have a 75 gallon reef/fish set up.  I skim 24/7 and the nitrates/nitrites are very low as well as is the ammonia.  I feed twice daily for the Chromis. I have something of an epidemic with what my local pet store calls red Caulerpa algae.  It looks nothing like the saw toothed Caulerpa that I have in my refugium.  Rather it forms small oval bulbs that branch and become a large ball of these bulbs.  Are there a lot of Caulerpa species? <Yes, dozens. The best coverage of the genus I've ever seen is in Baensch' Marine Atlas v.1> I have purchased a Foxface to combat it...? Should I attack it with an additional Zebrasoma? <Not necessarily... w/o knowing the size of the system this may be a poor choice... I would remove the excess on a regular (weekly) basis, perhaps with a tong-like tool...> Am I looking at dismantling the live rock and manually cleaning each stone? <I wouldn't> To everyone who might think this stuff looks beautiful, eliminate it as soon as you see indication of its presence!!! unless these guys say otherwise! Thanks for the help. <You're welcome. Bob Fenner>

Re: Caulerpa & Pictures & Phil, oh why? - 02/27/03 Greetings to the best crew on the Web: I have been reading a lot about the recent decline of Caulerpa's popularity. However, after reading the dailies (which I am addicted too, thank you), I followed this link: http://www.wetwebmedia.com/greenalg.htm and right there, under "What's Available:", you have listed as "The Best: Caulerpas".  What gives?  Is it just that you guys are overwhelmed with website maintenance (completely understandable), or is it still the best? <Quite possibly a matter of difference of opinion. Anthony appears to be concerned re the family of green algaes "exudations" are potentially dangerous (they are, but so is white bread in excess), whereas I am of the opinion that with general care there is not much of a problem, and that the Caulerpaceans capacity for 24/7 photosynthetic activity makes them winners for many applications... Could also be that there is a "temporal issue" at play here, with different folks' varying statements changing over time>   Just want to know before I go out and get some ;).  Thanks, Rich Ps: if/when I send a picture for comment, what is the best resolution/file size to keep it at? <Jpeg or bitmaps of about 100 dpi are fine> Also, did crewmember Phil really write/admit he was 15, or was that a typo? <This is Phil Bozek's age, as stated. He is an exemplary (young) person who had written an article placed on WWM and is (surprising to some) well-learned, written and desirous of sharing his knowledge and experience. Bob Fenner>

Manual extraction of Caulerpa sertularoides Esteemed Crew: I have followed the suggestions found on your wonderful site during my various battles with hair algae, bubble and Cyano.  I'm happy to report that it has worked and I've beat them all. <Ah, good> However, I cannot seem to win with Caulerpa sertularoides or cupressoides. I remove it with a long set of tongs, my fingers or tweezers.  Each time it frequently breaks and I end up leaving much of the "runners".  Each week, there is more and more. Can you recommend a good way to manually extract this stuff?  Maybe an affordable underwater handheld particle beam trimmer or something? <Mmm, there are gravel vacuums that you could literally drain your system a few times using... in attempt to remove all. But I suggest "biological warfare", the use of a predator to remove the remaining bits. Do consider placing a Zebrasoma species tang if it will fit in your mix. If not, please write back re the make-up of your system and will come up with other choice. Bob Fenner> Many thanks as always, Michael

Re: manual extraction of Caulerpa sertularoides I would be interested in a Zebrasoma, if you believe it fits.  I'm concerned about the fish load as well as compatibility with the other tangs.  If not, I would certainly appreciate other suggestions. <Mmm, looking at your stocking list below, I have high confidence that a smaller Sailfin, maybe a Yellow or Scopas would do well here> I currently have the following in a 110g 60x24x18 tank with 150lbs LR, 200lbs sand and a 30g sump. Tank houses SPS, a few clams, typical assortment of small inverts, good sandbed diversity. (1) Kole tang (Ctenochaetus strigosus) (1) Hippo tang (Paracanthurus hepatus) (6) Orange lyretail Anthias (Pseudanthias squamipinnis) (3) Caerulean damselfish (Pomacentrus caeruleus) (1) Diadem Dottyback (Pseudochromis diadema) (1) Six-line wrasse (Pseudocheilinus hexataenia) Thanks! <Should get along fine, with minor "jousting" accommodation at first. Bob Fenner>

2/6/03 - A few issues Hello everyone, <Sorry for the delay. Not sure how this one was passed up. Paulo, wiping the sleep out of his eyes.> I could use some advice. My reef is an 18 month old sumpless and skimmerless 65g w/ a 20g upstream refugium. The main tank has 80# live rock. 6" DSB, 400w m/h 10k Ushio. The livestock consists of 4 green Chromis, 2 false Percs, 1 lawnmower blenny. 12 assorted Montipora and Acropora frags all below 4" tall, 1 Sinularia, 1 small patch (3" round) of xenia and anthelia all separate from the SPS frags and 1 green BTA. The refugium has a 4" DSB, 65w pc lights, 1 small piece of live rock. The refugium "was" full of Caulerpa Prolifera but has all been removed and replaced with Gracilaria and Ulva. The water parameters check out okay, temp 82.f , calc 400 - 425, alk 3.5, sg 1.024, ph 8.2 . I add Kalk through a peristaltic pump set on a float switch. <Sounds like a nice setup overall. Should use a skimmer though> Until 2 weeks ago everything was in good shape. I had been running the tank skimmerless for the past 6 months. After hearing about the potential problems with Caulerpa at the last Boston Reefers meeting I had decided to pull all my Caulerpa. <Understood> This is where things seem to have gone wrong. I had pulled 95% of the Caulerpa at one time and replaced it with the new macro algae. <Good intention but maybe should have been less drastic and slowly removed some algae and replaced with the macro. Step by step process> I removed as much of the leftover debris from the Caulerpa forest as possible which still left a quite a bit of detritus in the refugium. <The reef hobby in general is becoming more aware of the release of growth inhibitive as well as the release of some of the nutrients that they are purported to ingest when Caulerpa are disturbed by breaking or grazing etc.> Since then I have been fighting mats of the black/brown/maroon Cyano blooms on the sandbed in both tank and on the glass in the refugium. <Maybe related to the above theory?> The polyps on some of my SPS have not returned to there former glory. A hairy Acro frag has not extended its hairy polyps since and the blue tips are not as bright as before. It seems none of the colors are as bright as before. The pod population does not seem to have shrunk but the amount of bristle worms seems to have gone down quite a bit. <Keep the water changes coming. I believe you stated you now have the skimmer running. Very good idea!> To remedy the problems I am experiencing I have done 3 x 10g water changes and put my hob skimmer back in service. <More water changes would not hurt.> I remove the Cyano when possible and the debris in the refugium. The refugium debris smells pretty bad. Instead of me asking a bunch of questions could you explain where I went wrong and the best way to remedy the situation.<Well, there are many possibilities here. Water changes with skimming will definitely help. Time will tell. Continue scrubbing and siphoning off with your water change regime. Running some carbon somehow would not be a bad idea either. There are many links available here on wetwebmedia try this: http://www.wetwebmedia.com/refugium.htm. See if there is not something that I may not have covered.> I hope I explained everything well enough but if you should have any questions please ask. Thanks in advance. <Good Luck. Pablo out> Tom G. Malden, Ma.

Growing Your Own Salad For Tangs! Hello, good day to you! I just love this website.. Months ago when I bought my LR, I had some Caulerpa algae growing on it but my yellow tang has made short work of it. I just bought a handful of Caulerpa from my LFS. I just anchored it to a rock with an elastic band. After doing some reading on your site I realized I'm missing something. Should I be planting it in the sand (5'' DSB) or what is the procedure to have it grow continuously? <Well- just about anything you do will encourage this stuff to grow! I'm not a huge fan of it, myself...However, if you want to use it- I'd let it attach to a substrate, such as live rock. It will rapidly put down holdfasts, and then it'll take off from there. Are you sure you don't want to try a different macroalgae, such as Chaetomorpha or Halimeda? These two are much less "aggressive", and have less potential to overtake other life forms in the tank. BTW- you may want to consider "planting" all macroalgae in a lighted sump, expressly for the purpose of controlled growth and nutrient export..> BTW any best algae for a yellow tang? <Gracilaria parvispora ("Ogo")! Hands down, the best macro for tangs, IMO! You can get it on line from Indo Pacific Sea Farms in Kona. Just get it! Your tang will go NUTS over this stuff!> Thank you very much :) Toast.. <Pass the guava jelly, please! Regards, Scott F>

Clowning Around With Macroalgae Greetings, <Hi there! Scott F. with you> A few months ago, I moved from a 15 gallon to a 33 gallon tank (with the 15 gallon as a sump).  My clarkii clown, which is about a year old, recently started swimming at the surface, and can not seem to dive any lower in the tank.  Physically he is showing no other signs of disease.  This does seem to be preventing him from eating though.  There is obviously something wrong with him, but I don't know how to treat it. Could it be a problem with the swim bladder? <This is a distinct possibility. At this point, I'd keep a close eye on him. Look for the appearance of other symptoms-labored breathing, obvious skin blemishes, excess mucus, etc. If any of these are evident, remove him immediately for possible treatment for a number of possible parasitic infections. Another "way out there" possibility, but one that has actually been documented by clownfish breeders, is "floating bloat". Apparently, this disorder is brought on by the clowns eating buoyant floating foods, like pellets. A long shot, for sure- but don't rule anything out. Check his diet out and see if you're feeding lots of dried foods...> I have live sand and rock in the tank, and a pretty low bioload.  The nitrates are about 20 - 30 ppm (higher than I want, but shouldn't be hurting the clown).  Any suggestions?  I really don't want to lose this guy? <Well- I don't think that nitrate is causing this possibly malady. However, you may want to consider a deeper (3-4 inches plus) fine sand bed, chemical filtration media (carbon, Poly Filters), aggressive protein skimming, frequent (twice weekly) small (like 5% of tank volume) water changes, use of high quality source water (RO/DI), and just general good husbandry procedures.> Another question.  I have a bunch of Caulerpa growing in the sump, but I am not sure I am doing it correctly. <BTW- another good idea for nutrient export> I have two 15w strip lights over it.  Is that enough? <That should be fine> The Caulerpa is just floating in the water, but is starting to sprout roots.  Should it be anchored in the substrate? <Caulerpa will put down "holdfasts" into substrate, rocks, etc. It can float, too-but will usually seek a surface to adhere against> How do I know when to trim it?  How dense should it be? Any help is greatly appreciated. Thanks, Paul <Well, Paul- Caulerpa can be amazingly prolific once it gets going. You'll see it begin to "mass" into large aggregations- that's a sign that it's time to start harvesting. The best thing to do is to carefully pull fronds away from the main "mass" of Caulerpa on a regular basis (like weekly), taking care not to rip them, as they may leach undesirable substances into the water. For a lot of reasons, I'm not a big fan of Caulerpa. I think that you could do much better with other "purposeful" macroalgae, such as Chaetomorpha ("spaghetti" macroalgae) or Gracilaria ("Ogo")- my two favorite macros, and even Halimeda. They have many of the benefits of Caulerpa (rapid growth, high nutrient uptake) without the potential downfalls (leaching of undesirable substances, difficulty in eradication, etc). Give one of these other macroalgae a try...The Anthony Calfo slogan "Friends don't let friends buy Caulerpa" is my mantra, man! Good luck! Regards, Scott F> Clowning Around With Macroalgae (Pt2) Scott, <At your service> Thanks for the reply.  I have since added PolyFilters and carbon, and changed about 12 gallons of water, but the clown has gotten worse. <Sorry to hear that> He is now no longer on the surface, but still having trouble swimming.  He seems to go aimlessly around in circles and bump into everything in the tank.  Yesterday, he also became "curled" to one side.  His eyes are sort of bulgy, but I cant recall if that is the way they always were. Since he is bumping into things and not able to get food, I have been wondering if he is having trouble seeing. No noticeable skin conditions.  I do have about 3-4" sand and a skimmer (a Berlin air-lift) in the sump.  Is that enough? <That sounds okay> Is there any medication that I could try?  I could put the clown in a small quarantine tank while doing so.  If not, I don't think that he is going to make it much longer... <Okay, Paul- it's time for some action! Because you indicated that the fish's eyes are bulging, I'm going to make the assumption that we're dealing with a bacterial infection of some sort. I'd place the fish into a separate aquarium for treatment with a broad-spectrum antibiotic, such as Maracyn. Follow the manufacturer's instructions exactly. I think that with quick action, you can save the life of this little guy. Hope this helps!> Thanks for the info on the Caulerpa.  It has been the only macroalgae that I have been able to find in any of the stores around here.  I'll start hunting for something else. Thanks, Paul <Yeah- Caulerpa is probably the most readily available macroalgae, but it's "dark side" makes it a lousy bargain, IMO! Do look into those other macros-you'll really like them! Good luck...Contact us again if the need arises! Regards, Scott F>

Harvesting Caulerpa Dear Crew: At Anthony's suggestion I set up an upstream refugium for my 80G FOWLR a few weeks ago. (see attached photos) Very nice job> I set it up so that the water is pumped up into a 10G tank with sand & some LR. This tank contains the heaters and a small venturi skimmer serving as an ozone reactor for an Aquazone 100 The water then drains down a 1" PVC standpipe into an 18T. <excellent... multi-tiered <G>> The 18T contains a DSB and a chunk of Kupang Island LR with lots of great life on it, including a lot of thriving Caulerpa. It has grown at least 50% over the past 3 weeks. I have also added some other algae. Lots of little critters are growing, including tiny brittle stars, mysids, & 'pods. Lighting consists of 2 13W compact fluorescents. This tank gravity drains by a drilled overflow into the main tank. Unfortunately, I obtained the LR with Caulerpa before reading your newer FAQs about all of its disadvantages. (Older posts are more favorable). <correct... revelations in the industry now that more aquarists are abusing it and growing it in larger quantities> At this point, I'm pretty well stuck with it. <only if you want to be> My question therefore, is how do I best harvest the Caulerpa for nutrient removal? <be very systematic (weekly, twice monthly, etc like clockwork) and never break or cut fronds but full up entire strands instead (thin the colony... don't "cut" it back). Else you risk vegetative events and sapping of noxious elements> I've heard that it should not be cut. What is the best method and frequency? <as per above... and never let as much as 3 months go by without harvest (risk of sexual reproduction and tank wipe-out> Thanks again for your great advice! I am certain that I am better off at this point than I would have been without it. Steve Allen. <good to hear my friend. Anthony>

Converting Caulerpa refugium to misc. algae Mr. or Mrs. Crew, <I'm "baby bubba crew" <G>. Anthony Calfo in your service> Anthony was kind enough to come to the Boston Reefers meeting and shock a number of people including myself about the toxicity of Caulerpa. <my great pleasure :) > I "had" a 20 g. refugium full of C. prolifera plumbed into my 65g SPS only tank and have since removed it all and have added some Ulva, Chaetomorpha, and left in the small amount of C. brachypus that was left. <the Ulva is fine although not a reliable means of nutrient export. Little harm either. Do enjoy. The Chaetomorpha is excellent though. Do focus on it. It is superior habitat for microcrustaceans (producing plankton) and far less noxious than Caulerpa. It is multicellular and does not suffer from pruning like Caulerpa. And it is more stable and less work too. Good choice> I suspect the tank may go through a diatom bloom or two with all the chaos going on. <no worries... just be on top of that skimmer. Make it work daily for at least the next couple of weeks to prevent any possible bloom> After the Caulerpa was removed I noticed a 1/2" layer of detritus covering the refugium, should it be removed or just left in there? <I would definitely remove it. Sounds like your flow is a bit too slow in the refugium too. Please increase water flow here> Besides the algae I have already added is there any else I should add? Is there any other advice you can give that will help in the conversion to "safer" algae. Thanks in advance. <no worries my friend. Just good flow, bright light, systematic harvest and you will have a less noxious and more productive vegetable filter/refugium for it!> Tom G.  Malden, Ma. <best regards, Anthony>

Caulerpa (poisoning your corals in the long run) Hi I am thinking of setting up a EcoSystem Filtration system for my 60gal. reef. But what's the deal with Caulerpa (poisoning your corals in the long run). Thanks Dave. <Overrated warning in my estimation. If you keep the Caulerpa pinched back, especially illuminated 24h/day, you should have little problem. If in doubt, there are other algae to consider. Please see the refugium, algal filters, and algae group sections posted on WetWebMedia.com Bob Fenner>

Macro-algae I'll try to be quick and to the point because I know you must get tired of answering Caulerpa questions. I have a 40g FOWLR (40lbs) system, skimmer, hang-on whisper filter. I would like to add some mexicana for looks mostly, something for fish to nip on, and to help outcompete nuisance algae. <I hope your lighting is up to the task. You don't need a lot but you could use at least 2+ watts per gallon unless you use Sawblade Caulerpa. I used it in a QT tank with no artificial lighting for over a year and it grew and reproduced to the extent that I had to harvest> Tell me if my statements are correct - comment where necessary. #1) This would be mostly beneficial to my system since I don't have to worry about coral growth. <Yep...But if you ever decide to eradicate this stuff, it's really difficult to do> #2) This will help "outcompete" some nuisance algae. <Yep...That's the theory> #3) Has the disadvantage of going "sexual" but with careful "thinning out" should be ok. <I've never had the problem> #4) Since I have LR and a good skimmer, the added "nutrient export" does not add much benefit to my system in this regard.  <You can't possibly get too much nutrient export> Now a couple questions. #1) Reading all the FAQs on careful maintenance, will fish nipping and eating it cause it to "bleed" (as I've heard it referenced as) causing pollutants to my tank? <Yep and so will your harvesting. Use of carbon in your sump will help control this problem and it is dangerous to fishes...it just makes the water look yellow> #2) Will my coralline algae be hampered and outcompeted by this other form of macro-algae? <Possibly if you let it get out of hand> #3) Is there a better green macro that is aesthetically pleasing and have the same benefits with less problems? <Does it need to be green? If not, Gracilaria is great. Tangs love the stuff and it grows pretty easily. Feather Caulerpa is beautiful but IME it tends to be finicky and fragile> My LFS seems to have a large supply of a few different types of Caulerpa so I'm fairly certain I can attain a good sample at a good price.  <Sounds good to me> Thank you as always for the time. <No problem. Hope I've helped. David Dowless>

Caulerpa in my refugium ? Dear "Anyone that will answer"   :-) <I feel like "someone" :)  > I have a 55 gallon live rock tank with a few pieces of coral, mushrooms, polyps...nothing major.  The tank also has about 10 fish.  The tank is about 2 years old. I am building a refugium in the Eco system Method... <sorry to hear it... heehee. Joking (half at least)> with 4 baffles filled with "Miracle Mud" and Caulerpa on a 24/7 light schedule. <a secret: the "miracle" to Miracle mud is that people actually pay that much money for soil> At least those WERE my plans until I was reading in the FAQ section that Caulerpa produces toxins to corals and would be considered bad if I was planning on adding coral one piece at a time every month or so. <hmmm... more information needed here for sure. Caulerpa is NOT the devil incarnate and it can be very useful for nutrient export. However... it is very labor intensive and potentially volatile. And I am not referring to events of sexual reproduction (only). That can easily be skirted by systematic thinning of o colony to stave off completion of a its life cycle (3-6 months for most species in the genus). 24/7 light (stasis) may do the same. There are far more serious concerns with Caulerpa regarding anti-biotic and anti-fouling exudations which harm coral on a daily basis and slowly concentrate in the system. Any benefit you seek from Caulerpa, I can name a much safer algae for use in your vegetable filter. Gracilaria ranks high... true turf algae (Chaetomorpha and the like) are even better if using algal mats> So now I am confused. First I went from wanting to add Caulerpa to the  refugium and put it on a reverse light schedule from the main tank.   <I can dig the RDP photoperiod for pH stabilization> But then after researching Leng Sy's specifications, he called for a full 24/7 daylight schedule for the Caulerpa so it NEVER produces and releases the carbon dioxide, toxins, chlorophyll into the water. <that last string of claims is not exactly true... the toxic exudations are unrelated to acts of sexual reproduction. Caulerpa sheds them just like coral shed nematocysts and various allelopathic compounds. All must be addressed with regular water changes and carbon/ozone. I like weekly for water changes and carbon (small and consistent amounts)> So what do i do? <cheer loud for the Steelers next Sunday playing against Tennessee> I've heard that deviating from his plans just a little bit (by not adding the baffles, not using Miracle Mud, and not having the right kind of Caulerpa, as well as the 24/7 mandatory light schedule) is what seems to make most folks fail at his method's proven success. <I would argue instead that modification of his good idea can make it even better! Keep the mud, run the lights on a reverse period, don't use Caulerpa, do protein skim aggressively, and enjoy a better refugium for it> If Caulerpa is the "demon" macro algae that I am reading so very much about in the FAQ section, <and beyond! There is a mountain of scientific information to support its effects on corals and fishes if abused.> then why does the EcoSystem work so well?   <by virtue of the many different ways that various aquarists succeed or fail to succeed in aquarium husbandry at large> Thru my research on the net, it seems his methods don't leach any toxins into his tanks.   <'Net research! Ughhh! Please, bud... completely anecdotal (including our forum right now) if not commercial (not us). If you want good research... get hard data... real science. I'll give you a page full of references to run down if you like (boring). And like Chris Farley said... "You can stick you head up a cow's..." er, well... "just take the advice of the butcher." Not just a bunch of aquarists with one and two year old tanks saying "everything looks great". Noxious exudations take many months to take a toll on coral and fish health. We are talking here about a long view of health for your reef aquarium> I suppose that's because in his method, Caulerpa is harvested regularly and never allowed to reproduce.  Do you feel that having the lights on 24/7 is possibly the BIGGEST reason why the Caulerpa in his setup's don't leech these "toxins" you all are saying it does? <I am certain that Caulerpa leeches them despite marketing claims> I'm also wondering if I should still continue to build my refugium using the EcoSystem Miracle Mud's schematics. <experiment and adopt the parts you like best. Strike out on your own... and Go West... Go West, young man.> My biggest goal here is to get my nitrates down to near zero WITHOUT the use of a protein skimmer or other artificial means. <Good heavens! You made me take the long way around the barn for that! <G> Dude... a five gallon bucket filled with 60# of oolitic sand and tapped with a bulkhead at the top... water flowing inline on the way down to the sump. Please... NNR (natural nitrate reduction) for the cost of a bucket (50cents) and a bag of Southdown sand (less than $3). Much better nitrate reduction with almost no maintenance headaches> I just don't have a whole lot of room for such peripherals in my main sump. Please advise on what, if anything I should do to get my refugium up and running properly. I don't want to poison my corals, but at the same time, I want to reduce my nitrates as low as possible. <deep sand bed my friend> Other macro algae's were mentioned.  Which is closest to having a Caulerpa-like nitrate reducing effect without producing toxins?  Also, would I still need to leave the lights on 24/7 with any OTHER macro algae besides Caulerpa? <Caulerpa is one of the only algae that can permissibly be illuminated 24/7... others will die without respiration> Thanks again for all your help.  I am learning a lot here. Regards, Steve <excellent to hear, bud. Best regards, Anthony>

Bits and Pieces Thanks for your helpful input!  It brings up a few other questions, though. <One thing always leads to another in this hobby, huh?> (BTW, I think I will go for a single Firefish) <Good call> 1.Although the Kupang Island LR has lots of great coralline algae and other nifty things on it, I have come to hate having Caulerpa in the main tank. <Good! This stuff can be...well- a pain. I mean, I like it-it has it's uses- but there is definitely a "dark side" to its use.> Little bits and pieces break off & float everywhere--difficult to keep clean. I want something to basically eat it all up. Which would be better for this, the Yellow Tang or the Flame Angel? <I'd give the edge to the tang. However, sometimes, you'll get a tang that doesn't eat Caulerpa (a Gracilaria "snob", perhaps?). But usually, the tang will have a definite impact.> 2. On the other hand, the Caulerpa is working out quite well in the refugium. There are also lots of creepy little white things swimming around in there now. <Sounds like Mysis...a great natural food! If you are employing Caulerpa as a means of nutrient export- do harvest it carefully on a regular basis, BTW..> Are there any good detritivores or other useful creatures that could be added without risking them? I have a few snails with conical shells (Trochus?) in the main tank (came with the LR) now. <I'd stick to the Trochus, Strombus, and other "grazing" snails in the refugium.> Which gobies do you favor and how long should the tank have been running before adding one? <I really like the Stonogobiops species (shrimp gobies)- these are really neat fishes; they stay small, and are fun to watch. You might also want to try a blenny, like the "Midas Blenny" (Ecsenius midas), or one of the Meiacanthus blennies (these are some of my favorites), which are colorful, small, and active.> In reading various entries in Scott W. Michael's PocketExpert Guide to Marine Fishes, I see that he recommends feeding most of them "at least 3 times per day."  I certainly do not have time to feed more than once or perhaps twice per day (though my Hogfish seems to want to earn his name with a seemingly insatiable appetite). The adage in freshwater is often "a hungry fish is a healthy fish." Is there a general rule of thumb for feeding typical marine community fishes? Thanks again, Steve. <I had the pleasure of spending some time with Scott a couple of months ago, and I posed to him the same question. He stressed that the fish don't have to be fed 3 times a day, but that they should be fed well. In other words, use common sense. Make sure that everyone gets food, but don't just dump a large quantity of food into the tank and forget about it. Careful, targeted feeding a couple of times daily is certainly better than careless heavy feeding! Believe me, it's really tough to feed a fish so much that they won't want to eat again for the rest of the day...These "stomachs with fins" are always looking for that next meal! Have fun selecting your next fishes! Regards, Scott F>

Just saying no to Caulerpa Hello Crew, <cheers, mate> It's Howard form Wisconsin again. Still trying to get my new refugium going. My older refugium is 30 gallons, 6+ inch fine sand bed, 20+ pounds of live rock, lots of bristle worms, 150-200 gallon flow through, and fed from show tank overflow. <all very cool> It is choc full of Caulerpa racemosa. <Doh! That part is not cool. One of the most toxic even among noxious Caulerpas. A wonderful nutrient export vehicle, but labor intensive and inhibiting to coral growth. If coral growth is no biggie... then you may be able to enjoy this Caulerpa> Since I got it going I have had no detectable nitrates (Aquarium Systems Sea Test Low Range). I cut out about a third of the growth every week (tang food and gifted to LFS). <excellent... this is one of the keys to succeeding with Caulerpa... prevents terminal vegetative events of sexual reproduction> I want to replace the Caulerpa with another macro after reading about Anthony's [comments on Caulerpas] dark side". <very cool... less work at least with same benefits in another alga> My new refugium is planned primarily to grow amphipods cleaner and peppermint shrimp eggs and other natural foods. It has 6 inches of fine sand and about 15 pounds of live rock. I must have macroalgae to feed and shelter the 'pods. Also, to learn more about the Caulerpa substitutes. <OK... agreed> I have been very unsuccessful in growing Ochtodes, Ulva, or Gracilaria. All gradually turned white and disintegrated. Also, "tang heaven red" (Gracilaria) lives on but doesn't expand. <actually... the Ulva and especially the Gracilaria should have rather easy to culture as non-calcareous species. Simply requiring bright light and reasonably good water flow. Did they die shortly after acquisition... this would suggest acclimation or source. Else, post 2-weeks... your water parameters are implicated. Caulerpa is one of the few algae to stand low light low flow and still survive (rat weeds are funny that way <G>)> Penicillus and Udotea flabellum are doing ok but are slow growing and not famous for "exporting" nutrients. <exactly as we'd suspect from calcareous species> My basement refugiums can be "restarted", flowed, fed and lit any way imaginable. My questions are: What are the ideal conditions to grow the available non-Caulerpa macros such as Gracilaria and Ulva? Flow?, lighting?, turbulence?. Raw overflow or filtered water? <raw overflowing water of moderate to strong turbulence in shallow brightly lit waters> Can more than one type be in the same tank - compatibility? <never recommended... energy is spent on competition instead of growth... just like corals> Is my overflow system water too clean and I need "fertilizer"? <very unlikely as long as you are not pre-filtering> Should the Gracilaria and other fine plants be allowed to float or be stuck under a rock? <depends on the species... I prefer free-floating for vegetable filtration harvesting> Finding a replacement for the no-problem, grows like crazy, Caulerpa has not been easy. <there are numerous choices my friend. Chaetomorpha is not very sexy, but one of the very best for pod culture and nutrient export. Do consider as well. I personally like the Gracilaria> Howard <best regards, Anthony>

Lingering Ammonia (Follow-up) Scott, thanks for the information about my ammonia problem, I removed the Caulerpa that had been in the tank since day one, and two days later it's down to almost 0ppm. <Really glad to hear that!> I put the stuff in a 5gal bucket  and it has set for two days and it smells like dog food. <Hmm- finally a good use for Caulerpa! Talk about "nutrient export"! Woof!  Keep up the good work! Regards, Scott F>

Re: Help with Refugium Hello Dr Fenner, <Just Bob, please> You helped me a while back with some questions I had concerning a mini-reef 25g hexagon tank, a mad clown and a Prizm skimmer. For some unknown reason, the skimmer is back on line and working fine again and the mad clown has had to be taken back to the pet store and exchanged for a more docile one. Reading through your FAQ's and website, I am sold on your thoughts and philosophies and went ahead and purchased your book "The Conscientious Marine Aquarist" which I read in one clean sweep until my eyes began to bleed, absolutely fantastic reading. I am also sold on the idea of a refugium to aid water quality. <A worthwhile addition> The water parameters in the main tank have all been stable for about 4 months (tank 6 months old), with the exception of Nitrate which sometimes goes as high as 10ppm. <Soon to be diminished> I have purchased a 15g tank (18x12x18) which will be set-up as a down-stream refugium and would like to know your thoughts on the following: - 4in sand bed - 15kg (33Ib) of live rock - Your thoughts on suitable macro-algae. To be honest, the only things that I can find the LFS selling in the UK is Caulerpas and Mangrove pods. - Lighting 1 x 15w (PowerGlo 18k spectrum) <All sounds fine... though many of my cohorts think otherwise, I would use the Caulerpa (leave the lighting on 24/7), being careful to not let it "get away", overgrow the system... watching for any ill-effects of its abundance... Perhaps keeping an eye on your suppliers for other macrophytes to supplant it with in coming months (like Halimeda, Gracilaria...)> My concerns are the use of Caulerpas in the refugium considering I have a few soft corals in the main tank (Leathers, Mushrooms, Sinularia & Xenia's) and the lighting on the refugium. Should I use a reverse cycle or 24/7? <I would leave the lighting on (with the Caulerpas) continuously> On my existing live rock in the tank, I have noticed an amount of copepods milling around in the night time (sitting there with my flashlight, much to the annoyance of the misses) and hope to have a similar introduction in the refugium. <You will> Thanks in advance for your help. Kind Regards Sandeep <Be chatting, Bob Fenner>

Re: Caulerpa I liked your page on Redox (checked it for use in a class on wetlands), but PLEASE don't recommend using the alga Caulerpa anywhere!!!! It has become one of the most noxious, damaging  exotic species in the world, wiping out of much of the natural biodiversity of the ocean bottom in the Mediterranean, and now creeping up the California coast.  It should be widely identified as an absolute "no-no" for aquarium owners!!! Joan G. Ehrenfeld Professor Dept. of Ecology, Evolution, and Natural Resources 14 College Farm Road Cook College, Rutgers University New Brunswick, NJ 08901 <Thank you for your input. There are others here who dislike this family of algae for other reasons. The Caulerpaceae are banned in our part of S. California as a "too-dangerous" noxious weed... and NOTHING should be released to the wild IMO. Bob Fenner>

Dreadful Rat Weed <G> Caulerpa Several days ago the Caulerpa in one of my refugium's went sexual causing some major water problems with my system.   <all too common. I'm sorry my friend> I will never have any significant amount of it in my system again.   <exactly the crux of the issue my friend. You are quite correct! Small quantities kept in check can be enjoyed with little or no trouble at all. It is the recent popularity of keeping Caulerpa in refugium and garbage can full portions (!) that has made us realize how toxic the stuff really is (inhibiting corals and fishes). I just e-mailed an interested aquarist 9 pages of scientific references on Caulerpa toxicity. What a dreadful macro for reef tanks (specifically)> The only saving grace is, at your recommendation, I have been in the process of removing the stuff for several months now and I didn't have a huge amount left.  If this had  happened a month or two ago I would have had a full scale disaster. <I'm grateful not to hear that story... I hear too many of them every month> Since the "event," I have noticed a drastic reduction in the number of little critters in both refugium's and my main tank.   <oh, ya> I would assume (love that word) the "event" took them out.   <Does a bear bring a readers digest into the woods?!? I mean... yes. I agree> Except for one of my cleaner shrimp that has gone AWOL (hopefully just molting, beginning to get worried though) <hope is the single greatest gift to mankind> my corals and fish survived well.   Anyway, I was wondering if you had any information on transplanting Padina and Sargassum?   <both are very attractive to me, but Sargassum has similar toxicity issues (although not as severe as Caulerpa). Neither mentioned are very good in aquarium for nutrient export if that was your goal. For that, look to Chaetomorpha, Gracilaria or even turf algae species in a proper scrubber> From reading your site I understand it is very stable?   <agreed... although not as stable as some calcareous species like Halimeda> I have a good supply of both in my main tank and would like to transplant some of it into my refugium without moving the LR it is attached to. Can it just be pulled off the rock, rubber banded or wedged on/in rocks or does the entire hold fast need to go with it?  If so, is there an easy way to remove it intact?   <clip/snip at the base of the plant with poultry/chicken scissors to skin rock with the plant> The Padina (ribbon) is exceptionally beautiful and I would like to ensure its survival in the refugium. Should the Padina and  Sargassum be lit 24/7 or on an opposite lighting schedule from the main tank?   <they can be lit opposite if you like for pH stability, but not 24/7 like Caulerpa... (no stasis here)> The other refugium has . . .  will have sea grasses.  Any help on this matter would be very much appreciated.   <excellent... seek Thalassia from any merchant you like that seems to have a good supplier for Atlantic species (hermits, turbo snails, etc). Best regards, Anthony?>

Caulerpa Control Hello All! <Good evening! Scott F. here tonight!> I have a mature 75g tank, with excellent water quality and have never had any major problems (thanks, in no small part, to your website!). <Glad we can be of assistance!> Several months ago I added some liverock with several types of Caulerpa on it.  The Caulerpa is doing very well, my Blue Tang is very happy with his eat-in kitchen, and the tank looks great! <Awesome!> However, it's getting to the point where the Tang cannot quite keep up with the algae, particularly the hair Caulerpa. I trim the Caulerpa (more like pull out HUGE chunks of it) on a weekly basis, but it's getting to be very difficult to do so, due to tons of baby starfish that like to hide in the Caulerpa (I emailed you about these guys a while ago). <Caulerpa is a very aggressive-growing, prolific macroalgae. It can be difficult to eradicate once it gets established. Part of the reason why many of us are becoming decidedly anti-Caulerpa!> My question is: Do you think it would be OK to add a Yellow Tang to eat up some of the algae?  I think my tank could handle it, as I only have the tang, a couple of Chromis fish, two ocellaris clowns and a Flamefish. So, given that my Blue Tang is medium-large sized, could I get a small Yellow Tang so that there's no question of dominance?  Am I inviting trouble?  If the Yellow Tang would not be recommended, is there some other form of algae control (not elimination, just control) that you would suggest? Thanks! Jes <Well, Jes- I think tangs are a great natural macroalgae control, but IMO, your tank is a little too small to accommodate both of these fish for their natural life spans. I know a lot of hobbyists will disagree, and many people do maintain this combination of tangs without troubles. They will get along, given enough space and resources. However, blue tangs can reach almost a foot in length, and the yellow tang also needs a lot of room as well. If you had a larger (100 plus gallon, 6 foot length) tank, then I'd be inclined to say yes, this would be a good idea. This is my opinion, of course, but I really think that it would be better to hold off on that second tang. I'd still recommend manual extraction of Caulerpa from the tank, in addition to keeping your tang fat and happy!. Good luck!>

Caulerpa Refugium Dear WWM Crew, I've acquired some Caulerpa. I think I've identified it as razor Caulerpa, Caulerpa serrulata. Is this a good algae for my new refugium? <It depends on the intended purpose of the refugium and your tanks needs.> Should I allow any in my display tank? <Again, it depends.> My refugium will be 22" x 24" x 10" high and will have 2" of Miracle Mud. How much shall I start with (I have lots) <You do not need too much.> and will it attach itself to the mud? <It should use its holdfasts to attach/"root".> Any other comments or suggestions would be helpful. <There is a lot of information on refugium types and macroalgae in our FAQ files on www.WetWebMedia.com.> My primary use of the refugium is to help control nitrates in my 180 gallon reef tank. <Caulerpa is excellent for nutrient control, but more and more research is showing it is harmful to corals. You are going to have to strike a fine balance here. I would also pursue some other means of nutrient control (protein skimming, careful feedings, appropriate foods and supplements, clean source water, etc.).> Thanks for your help, Brian <You are welcome. -Steven Pro>

The Crash (algae going sexual) My names Andrew and I'm a college student in LA. I'm doing a research project for my English class on the subject of Refugiums. <Man- all that we studied in college English was dangling participles, iambic pentameter- not even wet/dry filters...Man- things have changed!> I have done plenty of interest as I'm building one for my 75 gallon reef aquarium. What I'm asking is if you can recommend any sources or information on the Term; CRASHING. Crashing as in when the algae in the refugium turn sexual during the hours that light is not running over the refugium. If you could help, I would greatly appreciate it. Thank you for your time and thanks for having such a site. Its been very helpful in the past with my reef aquarium. Andrew <Well, Andrew, I'd start by doing a search of the FAQs on macroalgae on the WWM site, possibly using the word "crash" to see what comes up. Otherwise, you should investigate Caulerpa, which is often associated with "crashing"! Also, do check out Anthony Calfo's "Book of Coral Propagation" for more info on macroalgae and their use/abuse/benefits/pitfalls. Good luck!  Scott F.>

Refugium Dear WWM crew, I'm in the process of starting a 24"x24" refugium in my sump.  What is a good on-line source for Caulerpa?   <Check the links at Wetwebmedia.com I hesitate to recommend any specific etailer. There are numerous choices.> What quantities and type?   <Have you read about the pros and cons of using Caulerpa? This is also catalogued at WWM.> Does Caulerpa require quarantine or special acclimation?   <Many aquarist suggest QT for anything added to the aquarium. I personally only quarantine fish. But I am aware of the risk inherent in this method and I accept those risks. Acclimation is similar to the acclimation of fish and corals.> Do you recommend other (types/quantities/acclimation/quarantine) critters for the refugium as well? <I suggest starter cultures of copepods, Mysis shrimp, and similar critters. No fish. You can start your search with Inland Aquatics and IPSF (Indo Pacific Sea Farms). Thanks again for your service, Brian   <The pleasure was mine! David Dowless>

Friends Don't Let Friends Buy Caulerpa! Good evening! <Hi there! Scott F. here for you!> I just recently heard about utilizing mangroves in a sump vs. Caulerpa, searched your site for more info, found a little.  Was wondering if you could give me a quick run down on the pro's and / or con's of this, was just about to set up a new sump for Caulerpa when I heard about mangroves. <Well- first off- I wouldn't look at mangroves as a means of efficient nutrient export, like macroalgae. They grow very slowly...much too slowly to perform the same export function in a closed system as macroalgae. They do encourage the growth of various fauna within their root systems, however, so are interesting in that regard. You should purchase a copy of Anthony Calfo's "Book of Coral Propagation" for some really cool information on using mangroves, as well as more good stuff on macroalgae and nutrient export. A must read, IMO.> I am looking for a natural way to lower nitrate levels so I can start adding corals, liked the Caulerpa idea because I could cut off excess growth and feed to my ever-grazing Naso tang. Current tank is 120 gallon fish and liverock only with 29 gallon sump.  Thanks for any info you can provide, love your website!! Doug Edwardsville, IL <Thanks for the kind words, Doug! Although very popular, Caulerpa is not really the best choice for a purposeful macroalgae, IMO. After lots of personal research, reading, and discussions with the likes of Anthony Calfo, Eric Borneman, and others, I have concluded that there are more drawbacks than benefits to Caulerpa use. This stuff grows like a weed, true- and if harvested regularly, can export nutrient efficiently. However, should you rip segments of the plant through careless harvesting, many potentially noxious chemicals from within the plant are leached back into the water. Also, these algae have a tendency to go into a sexual reproduction stage, potentially releasing enormous quantities of gametes and other cellular material into the water, negatively impacting oxygen levels, among other things. I'd look into more "docile" macroalgae, such as Chaetomorpha, Ulva, and even Halimeda. They offer many of the advantages of Caulerpa, without much of the detrimental effects. As Anthony likes to say- "Friends don't let friends buy Caulerpa!" 'Nuff said! Good luck, and have fun working on this project!>

Caulerpa! Gentlemen, I am so confused on this Caulerpa issue. When I built my tank I thought if you build a refugium you got to have Caulerpa, now I am reading that this is very bad for my all my SPS that I dearly love. So do I pull this demon out of my refugium and fill it with a deeper DSB....but what about all that good micro fauna....or do I add some other nutrient export plant that will support the micro fauna and not cause havoc to my SPS? <Caulerpa is a fast growing plant, and can be efficient at nutrient export. However, it tends to overgrow everything in its path! If Caulerpa is damaged during regular harvesting (which you should do), it can release many noxious compounds into your water that can be harmful for corals. Also, Caulerpa tends to go sexual, and release its reproductive products into the water column, adding a serious organic load. I'd recommend other macroalgae, such as Chaetomorpha, which can grow rapidly, and can be harvested for efficient nutrient export.> By the way I have lost some SPS suddenly and now I suspect this green demon!! <Well- you never no- but could be...maybe...?> 135 Gal show tank 200 lbs LR.......45 Gal refugium mucho Caulerpa, Seaclone skimmer, emperor 400, light fish load some SPS, LPSs, soft corals...3 175MH  10K   ,2 URI...VHO blue actinics. I know this is a huge pet peeve of yours but I am writing this at work and can't offer any water parameters <><>ME SO SORRY<><> Thanks again in advance <That's okay, just read up on some other macroalgae. I think you'll find some that can be just as easy to grow, but not have all of the negatives associated with Caulerpa! Good luck! Scott F.>

Caulerpa Removal Scott, I have a few more questions regarding my refugium and our discussion.  I removed almost all of the Caulerpa last night but there are some strands here and there. Is it necessary to remove every single strand ? <To be quite frank- yes! This stuff can grow unchecked even from a single strand with good light and abundant nutrients! That's one of the reasons why it's such a "problem" in some areas! I have personally had the same experience that you are having when removing Caulerpa, and I can assure you that it will grow back if given the opportunity! I have vivid memories of plucking strands of C. racemosa out of a bunch of Chaetomorpha with a stainless steel tweezers (yep- I'm that anal!) > Also, I seem to get a lot of Cyano in my refugium mostly on the substrate surface.  Does that indicate that the water turnover rate is too low or is something else wrong ? <Good hunch! Yes- that is a definite possibility. Additionally, there could be abundant nutrients on the substrate that the Cyano is utilizing. This is an amazingly resourceful life form, that can adapt to a variety of environments. It is not always harmful in and of itself (although some species can be toxic to some animals if ingested), yet its presence is indicative that something is to its liking in the refugium! Do investigate increasing flow, check detritus accumulations, etc. Manually extract what you can from the substrate (granted, you don't want to disturb too much in there-hence the term, "refugium" !), and check water chemistry parameters. With attention to these items, and the passing of time, the Cyano should diminish.> Thanks Again, Chuck Spyropulos <Thanks for stopping by again, Chuck!  Regards, Scott F.>

Caulerpa Mega Problem Hi, Bob et. al., <cheers, mate> Thanks for your great site and continuous flow of good info. <our pleasure> I have a problem and I am seeking your counsel, once again. Over the past several months, I have had a couple of challenging situations in my personal life (including a terminal disease in one parent and an intermittent condition in my own heart), <good heavens! You have my empathy and prayers for a blessed turn uphill> so I have not been anything beyond basic life support of my reef. <understood... we must prioritize> My fish are doing well, though, and my soft corals seem to be hanging in there. The problem is this: I had placed some Caulerpa in the main 150gal tank <ughhh...> (I don't have a refugium, though I am considering it, now that things are leveling out a bit) I picked it up at my LFS, and unfortunately. it was unlabeled (and growing in their refugium). From the pictures I have been able find on the web, I am almost 100% certain it is not prolifera, taxifolia, mexicana, racemosa, and I am pretty sure it is sawtooth / serrulata or a variant. <do consult either of the works by the Littlers' if you want the definitive ID> Anyway, it very quickly attached to the live rock I placed it by, and started reaching out with long tendrils. I kept trying to cut those off, and to trim it back, which I managed for a while. But then all those other issues came up, and the Caulerpa just continued to spread. Every time I would try to pull out its holdfasts, they would just seem to break off, and little bits would float around the tank, lodge somewhere new, and start another clump. <yes... simply horrible> At this point, it occupies (by volume) probably 15 or 20% of the tank, and continues to cover over things. <not too terrible yet> It's down in the sand, as well as the live rock. (I must say, a number of my fish and conchs seem to like to hide in it). What can I do to get rid of all this Caulerpa, possibly moving it to a refugium, but frankly, not caring one way or the other. I could probably afford some more live rock and live sand, and could take out all the pieces that it is currently attached to, and just let it die off. <no need for that... to harsh and tedious> That would make it a bit tough on my good bacteria, but I don't have too heavy a bio-load, and quite a bit of filtration. Is there any biological predator or herbicide which would possibly be of use? <no herbicide that are safe, but plenty of natural predators. Take a sample of the algae to the LFS and feed to some Rabbitfish or small Naso tangs for starters to look for a candidate. I'd lean towards the rabbit/Foxface although you must know its spines are mildly venomous like a lionfish (no fatalities... just burn). Foxface are incredible algae grazers and generally quite peaceful> Thanks very much for any thoughts you can share. <don't encourage much Caulerpa in the refugium either... there is serious long term harm to coral with large masses of Caulerpa in the system> Sincerely, Jim Raub <best regards, Anthony>

Caulerpa Hi Bob This is Dan Garcia from Sacramento, {MARS}. I'm attending a meeting put on by the department of Fish and Game and the RIDNIS, the subject CAULERPA!!! The Law and punishment. {the meeting is on Nov. 19th} My question to you is, do you have any pictures of the different types that we use in the aquarium trade? If you do could I use them during my part of this witch hunt. If you have any question please call me at 916-419-XXXX or my cell-916-799-XXXX. By the way Karen sends her love <Yeah Dan... Got Caulerpa? You're a criminal! Oh, some pix here: http://www.wetwebmedia.com/caulerpaalg.htm Will these do... can you lift sufficient size, format off our sites? If not, make this known, will scan more, send along what you're looking for. Bob Fenner> Thanks, Dan Garcia

Creepin' Caulerpa! Hello gang, <Scott F. here tonight!> Thanks for helping me out on my past couple of questions over the last 5 months as I ease into salt water aquariums. I have one more that has popped up if you have the time. I have some macro algae that I am guessing to be Caulerpa peltata or something similar to it. It grows as a vine and has little round lily like leaves that are rather fragile. I have let it take over much of a single live rock in my tank but now it is starting to grow into my substrate. Will this be beneficial to the substrate, have some kind of negative impact, or not matter at all? My only thought is that it could make vacuuming the substrate a little more difficult in that area. Any advice would be great! Thanks, Andy <Well, Andy, as long as the Caulerpa is not growing into or over any of your corals or other animals, this should not be a problem. I agree that, if the algae makes maintenance difficult, you may need to remove the segments which are causing access problems. There are other considerations with an extensive growth of Caulerpa, mainly, its tendency to go sexual and release its reproductive products into the water. Further, many Caulerpa species are known to release noxious compounds that can create problems for the corals and inverts in your system. Their fast growth necessitates a high nutrient demand, which, if not met, can cause the death of the algae, creating a potential for massive pollution. Many aquarists "prune" the algae regularly, and this can also leach some of the aforementioned noxious compounds into your tank. Gee- I'm not painting a great picture, am I? I like macroalgae, in fact, I like Caulerpa-just understand the good AND the bad of this algae, and what effect it can have on your tank. I prefer the growth of more "purposeful" macroalgae, like Halimeda. As my good friend Anthony Calfo humorously asserts, "Friends don't let friends buy Caulerpa!">

How much Caulerpa is too much? Hello; <Howdy> How are you today?  <fit as a fiddle... a very old creaky fiddle> I have 2 types of Caulerpa in my tank, taxifolia and cupressoides. During the first two months after cycling, the Caulerpa didn't grow, and was just a couple sprigs of each.  <typical of many macroalgae and plants at first> The new tank went through the progression of diatom algae to red slime. Now that I have stocked the tank and started feeding...all the nuisance algaes went away.  <excellent... natural algal succession> The coralline is growing really well now and the Caulerpa has really started to grow more. In the last week to 10 days it has doubled in coverage. <"Houston we have a problem" <G>> I have read your articles on Caulerpa, and learned that it is okay as long as it doesn't grow too much.  <agreed> My question is: How does one know what is too much? I have a 29 gallon tank. <to be monitored by VERY systematic harvest (weekly, twice monthly whatever... but like clockwork) and be sure not to cut or break fronds if possible (causes sapping and risks a vegetative event). Instead... extract whole fronds to reduce breakage> I also didn't know that you should not dump it down the drain when disposing it!!! Thanks for your continued help: Kevin <a large presence of Caulerpa requires weekly/daily address of water clarity (ozonation, weekly changes of carbon) for concern with the significant compromise Caulerpa can pose on water clarity with yellowing agents. It also can release rather noxious compounds which are harmful or irritating to some reef animals if they are allowed to concentrate. Be sure to skim well and change water regularly. No rule on "how much" Caulerpa is possible as long as you maintain it strictly as per above. When so... you can enjoy this very attractive greenery and benefit from its merit as a significant nutrient export mechanism. Best regards, Anthony>

Caulerpa vs. Seagrass for Refugium & MM filter Anthony, <cheers, mate> I was reading through "FAQs about Refugium IV" section and you stated: "Syringodium manatee seagrass would be awesome here... many benefits to it as a refugium. Whatever you choose, though, PLEASE do not use Caulerpa... an awful thing to do to a coral system on a larger scale" Can you explain this further? I want to understand why would Caulerpa be bad in a refugium?  <yes... my pleasure. Caulerpa itself is not so bad, but rather easily mismanaged. For decades aquarists have enjoyed its benefits of great nutrient export with little trouble because we rarely did/could keep it in large masses (tangs, angels and other fishes eating it in check) and the lack of refugium applications. Now that refugiums have become popular, aquarists are keeping it in larger quantities and discovering the many pitfalls with it. The problem is that it is very labor intensive to maintain safely in large quantities. It must be harvested systematically like clockwork (!!!) and you should not cut branches (saps noxious elements and risks a disastrous sexual event of pollution)... instead each frond must be carefully hand picked and extracted to thin the colony. Caulerpa also contains some of the most noxious elements known that inhibit coral growth. They secrete serious discolorants into the water that require ozonation or weekly changes of carbon to maintain water clarity, and the risk of a sexual event (expelling all of the nutrients from growth en masses) can cause catastrophe in some systems. Other plants share similar negative qualities... but none so commonly and to the extent of Caulerpa. It is simply too risky in large quantities... BUT... I do enjoy and recommend it in small amounts. I'll publish a paper soon on the topic. Many experienced aquarists are discovering this dilemma with Caulerpa... I got some scientific references from Eric Borneman who is very much in agreement on the topic: ANYTHING but Caulerpa is better :) > Also, I am setting up a 350g (96"x24"x36") reef tank in the spring with SPS as the primary inhabitants.  <the your definitely do not want Caulerpa... shown to markedly inhibit the growth of stonies> The plan was to use and EcoSystem mud filter that uses Caulerpa.  <I see no significant advantage using Caulerpa here... although I do like the idea of you using a fishless refugium to generate natural plankton for your zooplankton feeding SPS (little phyto here)> The EcoSystem site recommends Caulerpa but states Seagrass can be used also. Do you believe Caulerpa is bad in this setup and would you recommend Seagrass as an alternative?  <definitely> If so, what are the pros/cons? <slower, safer and more manageable growth of seagrasses. Less noxious compounds exuded, a true plant that does not execute a sexual vegetative state/event under duress, more useful epiphytic material shed from the blades of the seagrasses... perhaps better support of copepods populations for it. Thalassia is a shorter seagrass species for refugia under 24"> Thanks as always. <best regards, Anthony> - Rob

Crab ID & Caulerpa Hi Bob. Firstly I would like to say how much I find your book helpful, it is one of the best books on the market. <agreed... WWM author Anthony Calfo> Now down to business. 1. Could you please identify the crab I have sent in an attachment,. It is about 1 inch across. <many such crabs are impossible to ID to the genus let alone species level for all but the Taxonomists. What you need to know is if it is safe or not. This crab by form and function that follows is clearly omnivorous leaning toward predatory. It may never cause a problem in your tank or it could begin nipping fish and coral tomorrow. As a rule... very few crabs are reef safe and larger clawed species like this may not even be safe with small fishes> 2. I discovered a few small snails the other day. They are grass green, both the snail and the shell. The shell is shaped like a scallop shell. At present they are about 1/4 inch long. <need a better description or pic, but do reference the shape of Stomatella species> 3.Tentacles keep appearing from the live rock. About 3 or 4 from the same crack. They are ringed (Black and light green) and about as thick as a piece of cotton. At present they are about 1 inch long. <many possibilities, but Ophiuroid starfish (baby brittles) commonly filter feed by sticking banded arms out into the currents> 4. I set up a plenum attacked to my main tank and placed some Caulerpa (Green looks like fern leaves about 3 inches long) in the tank, after about four weeks, the Caulerpa crashed. The water parameters are all fine, any possible idea what could have caused this? <Caulerpa is a miserable plant for refugiums for this and many other reasons. I would only recommend it in small quantities (any other macro instead please!). To answer your question... it likely had acclimation shock from the transplantation (too many broken branches sapped the cluster). Or it went sexual (a problem with larger colonies too that can kill your whole tank).> Many thanks Colin <best regards, Anthony>

Re: Antoine, pls see note on bottom below (Caulerpa, use in marine aquariums) Bobster... Thanks bud... duly noted. I have made mention recently of an article I'm working on detailing concerns with keeping massive amounts of Caulerpa in systems focused on coral growth. I just ran down some papers to cite and support the anecdotal observations. <Better to have a mix of species, Divisions... and keep the Caulerpaceans cut back> Gist of it all being... if coral growth is a primary goal/thrust in the system... then there are better (less noxious/less labor intensive) algae to culture. {did I mention that I wrote that Bill that passed in Cali banning that rat weed Caulerpa ;)? ) <You better not have... you may be swimming with the fishes soon... Bob> Coming to a theater near you...

DSB & lightly stocked FOWLR tank Hi guys/gals- <<And hello to you, JasonC here at your service.>> I was hoping you could answer a question or two for me. After I give you the specs. <<Shoot...>> I am in the process of upgrading from a 4 year old 55 FO tank into a 125 FOWLR tank w/ 40 gal refugium and 20 gal sump. The "gang" consists of: 1- 6" Naso tang 1- 4" Regal Blue Tang 1- 4" Sailfin Tang 1- 4" Yellow Tang assorted 1"ish original set-up damsels 1- arrow crab - 55gal FO "clean up crew" from F.F.E. (lots of crabs and snails) - 130lbs of live rock Equipment for new 125 FOWLR: -Berlin Turbo Classic skimmer -2 - Mag12 pumps for circulation -500w of compacts- 6x65 8000k daylights and 2x55 actinic blue I was planning on some sand and Caulerpa of some sort for the refugium. <<Any chance I can encourage you to try another macro algae besides Caulerpa? There are some other, more predictable options.>> Would this amount of livestock be ok for a DSB of 4-5"? Or should I go with the 1" or less idea in the main tank and have a DSB in the 39gal refugium? <<Yes, 4-5" would make a good sand bed, but an extra inch would help. You won't be able to accomplish an equivalent DSB in the refugium compared to the 125 because of the reduced surface area. If it were me, I would put a DSB in each.>> It sounds like the livestock will eat much of the cool stuff off of the live rock so I was considering having some of the live rock and the DSB in the refugium and skip the Caulerpa. <<Or you can rotate rock between the two so that you can offer that army of tangs something fresh and new every so often. Picking algae from the rockwork is what these fish do constantly in the wild - constantly. If you want to have showcase tangs, I'd do my best to offer them something as close to natural as possible.>> The refugium is mounted underneath the main tank and will be a display tank also. So I was hoping I could keep some of the live rock full of "life". <<Think about moving rock between the two systems - I think this would take you a long way.>> I have an extra Magnum 350 canister filter. Could it be useful somehow with the new tank? Maybe for calcium or something? <<For calcium? Heavens no... I'd use one as a substrate cleaner, or perhaps a ways to run activated carbon on the system... that's about it or perhaps EBay fodder.>> Thank you again. All of you are making me feel much more at ease about the upgrade. <<Glad we can be of service.>> Dennis <<Cheers, J -- >>

Caulerpa "the dark side" Dear WWM group, <cheers mate> I have a 30 gal. refugium with 4 inches of sand and it is almost full of Caulerpa prolifera. I put little bunches in the show tank and the tang devours it. I remove a big bag about every two weeks and give it away or throw it away. Since I put this box in series with my sump I have had no detectable phosphates and rarely any nitrates. It produces some copepods and bristle worms. <an excellent system IMO. Faithful/Regular harvest, nutrient cycling with an herbivore, small mass (little harm or good), etc> I am building a 35 gal. box to put in series with this one in an effort to produce more copepods and other natural food. Plans are to have Caulerpa in this box too. <Ok... here's where we disagree <G>. Small amounts of Caulerpa are very fine.. especially with dedicated harvest and small quantities... but large masses are asking for trouble> In a recent response (I read them all - WWM has been my bible since I got started), Anthony hinted at "the darker side of Caulerpa"? Please let me know a bit about this "darker side".  <actually... I've been chatting with our industry friend Eric Borneman about scientific references and citations to finish this article I'm writing about the common misapplication of Caulerpa for most (not all!) systems. I should have it done shortly... could I trouble you to follow up with a reminder if you don't see it posted in a week?> Should I try to find Halimeda or Ulva for the second refugium? <in the meantime...yes! Anything but Caulerpa if you want a large mass of plant matter> Howard
<with kind regards, Anthony>

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