Please visit our Sponsors
FAQs about Green Macro-Algae Reproduction & Propagation

Related Articles: Embracing Biodiversity, Green Algae By Mark E. Evans, Green AlgaeGreen Algae 2Avoiding 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: Caulerpas, Green Macro-Algae 1Green Macro-Algae 2Green Macro-Algae 3, Green Macro-Algae 4, Chlorophyte Identification, Chlorophyte Behavior, Chlorophyte Compatibility/Control, Chlorophyte Selection, Chlorophyte Systems, Chlorophyte Nutrition, Chlorophyte Disease, Marine 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


Chaetomorpha Growth…Or Lack Of… - 09/22/17
The subject title will make you go noooooooo,
but I've got a question I cannot find an answer to.
Ever since I've grown Chaeto, I've been successful in keeping it. Until recently. Nothing has changed, the available nutrients are still there, the red/blue light is still there and adequate flow is still there. I had my crop die over a period of a month, just disintegrated. I replaced it with another healthy handful which has grown slightly (nowhere near as fast as before), but is also disintegrating now. The question is, in your knowledge does Chaeto require anything other than the aforementioned, which it may be lacking? I have a flourishing sps system with close to ideal parameters.
<<The alga needs pretty much everything your SPS need…including adequate water flow. Some say the Chaetomorpha needs enough water flow to make it “tumble” but I have never found that to really be necessary. I keep Chaetomorpha in a 55g RDP refugium with a flow-through rate of about 450 GPH which has proven sufficient for more than a decade. Much of the water is directed to ‘flow through’ the alga, but it certainly does not tumble. If flow is not an issue, double-check water parameters. Another possibility is something is either attacking the alga (chemical attack), or maybe it is simply being outcompeted by the system/your other filtration.>>
As the coral have grown larger year on year, is it possible they are consuming what may have been previously available for the Chaeto?
<<Indeed…you may no longer need the Chaetomorpha, though I like it not only for its filtration properties but also as a habitat and nursery for the myriad of critters it hosts.>>
Kind regards,
<<And to you…EricR>>
Re: Chaetomorpha growth    9/26/17

Thanks Eric, you've confirmed what I had suspected.
Kind regards,
<<Happy to assist...EricR>>

Chaetomorpha dying off in low Magnesium environment - 8/17/12
Many thanks for the maintaining the website and answering to our troubled questions. I just wanted to share the experience with dying off Chaetomorpha in low magnesium. I quickly searched WetWebMedia FAQ pages but did not find a link between low magnesium and dying off Chaetomorpha. I hope this anecdote help fellow reefers.
<Assuredly so>
I went with Instant Ocean salt 3-4 months ago to save on cost and gradually developed inability to raise calcium and alkalinity above 375 ppm and ocellaris clownfish <?> 3.5 meq/L respectively. Chaetomorpha is loosely attached
to a glass wall in the tank with 110w LED light. However, the algae has recently stopped growing, and the most lit parts have lost green color and started to shed off. Magnesium was 1115 ppm (Seachem Magnesium test kit) vs. more than 1300 ppm 7-8 months ago. I started dosing Epsom salt and brought magnesium back to 1300 within two weeks.
Chaetomorpha started growing and returned to dark green 'curly' state in a week. I have never dosed magnesium before.
<The ratio (about 1:3) w/ calcium concentration is absolutely necessary w/ much non-vertebrate life>

Here are a few details about the aquarium setup: a 40gal shallow tank with a few soft corals (mushrooms, Zoanthids), LPS (Candy Cane coral, Frog spawn coral, Acan), two unidentified SPS frags, two Ocellaris Clownfishes, Bubble Tip Anemone,
<Mmm, misplaced w/ the other Cnidarian groups here>

 live rock, skimmer and Vortech. The system is 1.5 year old. I dose alkalinity, calcium supplements (Seachem) and iodine (Kent) and have just started Trace elements (Kent).  I might sometimes overdose either calcium or alkalinity as I move from one salt manufacturer to another one but bring parameters back though weekly Ca and Alk tests. I maintain calcium between 400ppm and 420 ppm and alkalinity between 3.0 meq/L and 3.5 meq/L (Seachem tests). I occasionally test nitrates, phosphates and iodine level but have never seen any spike. Corals and other inhabitants have been growing in the system for more than a year. I could not think of any other reason for dying off Chaetomorpha.
<Need measurable NO3 and HPO4... in this "age" of blind chemical filtrant use, this is often an issue>

 I will probably move back to either Tropic Marine or Reef Crystals once I finish Instant Ocean (+
trace + Epsom salt, etc.)
Best regards,
<And you, Bob Fenner>

Chaetomorpha raises pH 1/18/12
Dear Wet Web Crew,
I recently added a ball of Chaeto to a 10 gallon QT tank which I had running and noted an increase to pH 8.8 after just a few days. In my reading of different question/answer sites I've seen other hobbyists note the same, but always seem to have others respond that Chaeto alone would not increase pH as high as 8.8.  I disagree. It appears to me that the addition of Chaetomorpha to a marine aquarium may have the ability to raise pH to 8.8.  To prove out my theory I've started a small 2 gallon tank, with nothing except 1/2 cup of clean aragonite <aragonite> sand and 24 hour mixed saltwater @ 1.024, pH 8.4.  I then introduced a compact ball of Chaeto (about 4'x4').  The Chaeto is getting a high amount of light from large T5 Tek light hanging above.  3 days since putting in the Chaeto, and nothing else added to the tank, and my pH is now 8.8.  Is there any other explanation for the increase in pH ?
<I believe so.  The Chaeto is absorbing any excess CO2 that may be in the water which would drive down the pH along with the aragonite sand tending to keep the pH up by it's buffering qualities.  The absence of any nutrient producing animals in your systems also contributes to the high pH since there are no acids present.  I doubt it is actually 8.8 unless these readings were taken with a calibrated electronic pH meter.  Color comparator pH kits are not that accurate, ballpark figures at best.  I have found the LaMotte pH test kit to be far superior to the hobbyist kits but it is a bit pricey.>
<You're welcome.  James (Salty Dog)>

Halimeda Nutrients   8/18/11
Hey WWM,
I have read and often hear that Halimeda takes a lot of the nutrients from the tank. Other than Phosphates, Nitrates, and Calcium what other nutrients does it take from the water?
<Some Magnesium of elements hobbyists have test ability for... Other than these, other less to trace materials can be supplied through water changes, feeding of other livestock. Bob Fenner>

Codium, Mermaid's Fan, and Shaving Brush in same tank?    6/8/11
I've had several tall Codium in my DT for several months, and they are extremely healthy and growing well.
I've had a Mermaid's fan (Udotea) and Shaving brush plant in quarantine for 5 weeks, and they are also doing well.
So today I moved them to my DT. Then, as I was researching proper placement, I ran into a statement on WetWebMedia that macroalgae should not be mixed in the same tank. I never hear this before. Will these three items do well together, or should I remove something? Thanks!
<Mmm, well, this mutually-exclusive statement is too broad... There are some types/species of such algae that are known to be allelopathogenic (competing chemically) toward others, but the three you list should be compatible... have seen all together in close proximity in the wild. Bob Fenner>
Re: Codium, Mermaid's Fan, and Shaving Brush in same tank?   6/8/11

Bob - Thanks! By the way, I had a fascinating explosive Halimeda sexual death in my QT.
<Oh!? No fun>
I've read about it here and in several books, but I never knew it could be so profound.
My little bush about 4 inches high in the 28 gallon QT looked a little whitish one night, with green flecks all over the surface of the leaves, and I resolved to keep an eye on it because I thought I knew what was coming. The next morning, my QT was pea soup! Unbelievable. It went from crystal clear water to so thick you could not see three inches into it in a matter of hours. Wow! I'm so glad I still had it in quarantine! That could have been a disaster.
<Again, one of the more important "reasons" for not stressing "too much" these and other organism groups that can "go postal" so to speak. Cheers, BobF>

New Tank / refugium. Chaetomorpha hlth.   2/24/10
Hi guys & gals, sorry to keep harassing you but I just was viewing my refugium portion of my sump and it appears that the Chaeto is dying...the ends of it have little bulbs on them and there are a ton of empty stalks where I believe there was growing algae
I'm thinking that a cause of this is either that my tank is not fully cycled
<? This will do it>
yet so that Nitrates are quite high or the other cause could be the lighting that I have over it which is a 19 watt fluorescent working for approx 12 hours opposite to my tank lights
<If sufficient in photo-quality, this should be fine>
Could either of these be the cause and let me know any thoughts on how I should combat
Thanks again for your help
<Take a search on WWM: http://wetwebmedia.com/Googlesearch.htm
with the genus name and words like "culture", "health"... read the cached versions. Bob Fenner>

Chaetomorpha question 11/10/04 In Today's Q/A there was mention of Chaetomorpha and to allow it to roll around. Is this a part of the requirements for successful growth of this plant?  <Chaetomorpha does not root and does best when it is not allowed to simply lay on the bottom of the tank, but it is very forgiving.  I have successfully grown it without keeping it suspended.  IME, the most important thing is to thin it often and not allow it to become too dense. HTH.  Adam

Halimeda getting white - going sexual 3/11/04 Hello Anthony! <cheers, Thanassis> In my display tank, as well as in my sump, I have macroalgae growing (Dictyota, Halimeda and  a little Caulerpa racemosa). <please do resist mixing macroalgae species... they will not fare well together in the long run (competition and chemical aggression)> During the last couple of days I noticed that some -not all- of my Halimeda has turned white - I mean totally white colour. Does this mean it is dead? <sort of... it may simply have gone sexual and new growth will sprout in the system in the next couple of months. Else, it has suffered from the very toxic/noxious Caulerpa racemosa (one of the most noxious of all macros in the sea)> If yes, should I remove it from the tank? <you can let it dissolve and provide calcium. Also do a large water change> I checked my Ca Hardness is 11 dKH and Ca is 450. What could be the reason of this problem? <no problem at all here> Thanks, Thanassis <best regards, Anthony> Chaetomorpha Hi, I have just started a 10 gal refugium for my 26 gal reef tank. Tank has been set up about a year. I have ordered two different batches of Chaetomorpha and both have done the same thing. When I first get it it's light green in color and soft after about 1 to 2 weeks it turns dark green and gets really stiff. << That sound normal. >> It doesn't look like it is growing at all. I have an 18 watt florescent light on it running 24 hours. Any idea on what I could do to make it grow or may be doing wrong? << That doesn't sound like much light.  I would try at least 30 watts of compact lighting, and I would like the refugium for about 12 hours per day. >> Or does it take a while to start growing? << Well it is certainly not a fast growing algae.  And that isn't bad. Remember it can only grow as fast as the nutrients allow it to. So if you have a big skimmer in there, and you don't feed your tank, it won't grow. >> The Chaeto has been in there now for about a month and a half with no growth. One other question if it does start growing is it better to cut pieces off or just pull pieces off. << Good question.  It is better to pinch it off.  By this I mean you pinch it between your fingers first, then cut it off.  That way, the pinching helps prevent the alga from "bleeding" when you cut it. >> Thanks for any help you can give.    <<  Adam Blundell  >>

Halimeda gone sexual 6/3/03 Good morning: <Howdy> Overnight my Halimeda seems to have been attacked by red and green spots (in the terrestrial world I would call them spider mites) turning the plants white and the water has gone cloudy. <what has happened is that they have gone from being vegetative... either from a stress (newly acquired, or recently stress from a temperature or salinity change, e.g.)... or from a period of vigorous growth without adequate pruning which has allowed the colony to go sexual/mature> No fish currently in residence as they are in ick quarantine but my polyps remain as do the crabs, snails and LR. Should I be ripping the Halimedas out of there and what could be attacking them? <the bleached colonies are dead. New colonies are likely to sprout in the tank within months. Remove the dead matter and conduct a large water change. Use fresh carbon too> Thanks as always for your assistance. Charlie <kind regards, Anthony>

Green seaweed research questions (and useful, scientific input!) Hi Bob, I found your address at the WetWeb site and thought I'd contact you directly. Hope you don't mind. <Not at all> I'm a bio professor/researcher who studies the reproductive behavior of tropical green algae in their natural environments (Halimeda, Caulerpa, Penicillus, etc). I notice a fair number of posts to aquarium sites that have to do with "green clouds", "white" or "dying seaweeds", etc. and recognize (as you do) that most of this relates to the sexual reproduction of these seaweeds... a 24 hour conversion from sterile to fertile condition, followed by explosive gamete release at dawn and immediate death of the "parent". <Yes.> My research explores the consequences of these reproductive events on coral reefs (mostly Caribbean, though I'm currently on sabbatical in Guam). I'm particularly interested in what induces a seaweed to become fertile, since we often find hundred to thousands of algae on a reef (but never all of them) becoming simultaneously fertile... not only is the ensuing bout of sex the next morning a spectacular visual phenomenon.. the subsequent death of so many "adult" seaweeds has important ecological implications for the reef community as a whole. <Agreed> I notice from various posts within the aquarium trade that lights, chemistry, temperature, stress, etc, etc, are implicated in the onset or prevention of reproduction by green seaweeds in aquaria. Do you know of any formal treatment of this idea...  <No... unfortunately seem to be entirely anecdotal accounts... of "stress", change that bring on these events.> or is it just a hodgepodge of observations thrown out over time? I notice you reference "24 h" lighting as a preventative and I've seen reference to blue lights, or non-blue lights (can't remember which) having similar effects. If you're interested, I'd love to pick your brain about this... or you can sic me on someone else. <Very glad to be of assistance.> If interested, you can also learn more about my research on seaweeds by visiting: http://lclark.edu/~clifton/Algae.html <Thank you much for this reference. Will post to our sites (WetWebMedia) for hobbyist perusal> Thanks for your time... I hope to hear back from you. Ken Clifton <Sorry for the delay in response. Have been on a liveaboard... in the Bahamas. Be chatting, Bob Fenner>

Culturing Halimeda Dear Bob, Steve, or Anthony: <Anthony and at least two of my personalities here...Bob and Steve unavailable> I emailed you a couple of days ago regarding reducing the sand bed depth in my 150gal FOWLR system. I have already began the reduction and am pleased to report everything seems ok! Thanks for the good advice! <ducky...just ducky> I was wondering if I could pick your brain on one other item. I have a nice stand of Halimeda on one side of the tank, and I was wondering if it is possible to propagate this macroalgae by "cuttings". <not so literally, although reproduces sexually with ease once mature. best bets are rooting in sand> Or- is there a better way? If Halimeda can be propagated in this manner, do the "cuttings" need to be secured to a rock or other substrate in order to grow? <see above... although better to let it mature and reproduce naturally. A sexual event is indicated by a sudden "bleaching" of the colony leaving behind a bespeckled (with green) white plant that soon dissolves. "Babies" pop up everywhere afterwards within weeks to months. Skim well during the event> I'd appreciate any tips/comments/warnings you might have on propagating this macroalgae. <of course...you could always try good wine and Luther Vandross music> Thanks! Scott F <you are quite welcome. Anthony>

Halimeda Cycle Oh Wise Guys! <<and hello to you.>> I had an interesting occurrence this past weekend that I'd like to understand. I have a lot of Halimeda in my 100gal tank and about half of it went into the end of its life bloom (my poor term). You know, at first it turns white with tiny green spots or spores on the outer most leaves, then it releases these about a day later into the water causing a very cloudy condition. The interesting part was not the bloom - as I've seen it before - but the apparent suffering caused to one of two yellow-tailed blue damsels. For a day or two he showed signs of poor water chemistry. He was hiding, not eating or seen resting on the bottom. I immediately did a 5 gal water change. Then followed it up a day later with another 5 gallons. The fish seemed to recover quickly. What caused the stress? The Foxface, cinnamon clown, and yellow tang were also unaffected as was the red brain coral. <<Very hard to say specifically without some chemical analysis. Did you check any of the normal parameters... perhaps nitrates skyrocketed... hard to state at this point what the problem was exactly besides the obvious: something from the algae bloom/die-off.>> P.S. If I were to add one more way cool fish what would you suggest? <<Oh... the list is too long. Do check through the pages in WetWebMedia. Many, many to choose from.>> P.P.S. Finally bought Mr. Fenner's book at Scripps Aquarium here locally. Boy, I didn't expect so many beautiful photos. It can be a 'coffee table' book as well as a good reference. <<Indeed.>> Also, what happened to the Rabbitfishes (Foxface) section? <<If you look in WetWebMedia, you'll see these fish covered in the same section as the Tang/Surgeonfish.>> David
<<Cheers, J -- >>

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: