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FAQs about Genera Bryopsis & Derbesia Algae In/Compatibility/Control

Related Articles: Caulerpa Algae, Green AlgaeAvoiding Algae Problems in Marine Systems 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 Compatibility 1, Caulerpa Algae 1, Caulerpa 2, Caulerpa 3, Caulerpa 4, Caulerpa 5, Caulerpa Identification, Caulerpa Behavior, 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

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Marine Aquarium Algae Control

by Robert (Bob) Fenner

I need help IDing this. Grn alg.
<Four megs of blurry pix.....>
These grow in the brightest places closest to the light sources (t5). These near water return(sump) are much thicker/dense and darker in colour than those on same level but without so much water flow.
Rest of the tank is ... pretty clear. A feather here and there.
I attach pictures. If you could, please, confirm if I'm right or not, or ID it.
<Looks like this or Derbesia. See WWM re both. Bob Fenner>

Caulerpa Taxifolia?   Not    12/12/14
I purchased some Chaetomorpha from my LFS and placed it in the 2nd chamber of my Biocube. I am using reverse daylight with it and found another type of algae growing on the wall of the chamber when I checked it recently. It looks like Caulerpa Taxifolia to me but is growing in clumps instead of on a vine like I see in images. Can you verify if this is indeed Caulerpa Taxifolia or some other type of algae? If not Caulerpa Taxifolia, is this some other type of nuisance algae?
<Your image is too large, but also too poor to make out w/ any confidence.
Please re-try; send a better pic... more resolved, of a few hundred Kbyte size>
Bob Fenner>
Thank you very much for your time!

Re: Caulerpa Taxifolia?       12/12/14
Apparently uploading the pics to Outlook is degrading them.
<Nope; same crappy pix, and you sent five and a half meg.s this time. JUST READ ON WWM
. BobF>
I zipped the files and sent them to my husband as a test and he can see them fairly clearly. I am recharging the battery on my camera which should work better than my phone so if these don’t work for you I'll try again with the camera. By the way, the pics are all at least 1 MB in size. Sorry for the confusion and let me know if you still need better pictures.
Thanks so much!

Re: Caulerpa Taxifolia?    12/14/14
I am now educated on the way to submit pictures. I apologize for any inconvenience! Each picture is 600 x 800 pixels and is under 150 kb each. I took these with a real camera instead of the cell phone so hope the resolution is good for you now. I placed them in a zip file to maintain their resolution.
At least I had good grammar and punctuation in my emails
Thanks again for your patience,
<I do think this is one of the many species of Bryopsis. Please see the coverage of species on AlgaeBase:
Bob Fenner>

Re: Caulerpa Taxifolia?     12/15/14
Thanks again for all your time. Now to get rid of it. At least I don't have to worry about it polluting the environment when I dispose of it.
<Oh, do bag and freeze it ahead of putting it in the trash. And see WWM re Bryopsis and Derbesia. B>
Re: Caulerpa Taxifolia?
Will do!

Bryopsis I.D.
Do you happen to know what species of Bryopsis this is?
<The greenery to the right and left of the Aiptasiid? Nope>
Because I checked algaebase.org and It doesn't match any of the 43 Bryopsis photos they have posted and I didn't have any luck searching online either. The guy at the pet store said it most likely came in from the Caribbean but he didn't know the exact species. Not sure if that helps narrow it down but thought I'd mention it.
<Don't recognize it/this period. Do you have access to a 'scope w/ a USB attachment that you might make some close up images?
Bob Fenner>

Re: Bryopsis I.D.
I don't have a scope but I'm certainly willing to attempt some up-close and clearer photos with my camera for you. Or do you need footage at a microscopic level?
<Closer is best... one macro, a few at a few tens of power magnification>
How powerful a scope would it need to be?
<As above>
If their not too pricey I might get one.
<Oh! Do see my shameless plugs on WWM re the QX3 scopes by Intel/Mattel...

What kind of Algae is this?  7/28/11
I thought it was Bryopsis, but now I'm not sure. It's really starting to take a real hold all over the tank, and is tough to pull out. I had a turbo that would eat it, but it died.
<Mmm, a clue perhaps>
Now all the new Turbos/snails won't touch it..
<And this>
I'm currently dosing Kent tech-m, and at 1700 ppm Mg, but there seems to be no effect on it so far.
<Doesn't open>
<Fragments... does appear to be a Thallophyte (vs. a Moneran/Blue Green... might be BGA mixed in/on), but... perhaps Derbesia... There are a few approaches to control. Read here: http://www.wetwebmedia.com/marine/maintenance/maintindex.htm
scroll down... Bob Fenner>

Re: What kind of Algae is this?   7/30/11
Thanks Bob for the reply,
Here are some better pictures of the menace algae, this was one clump of it. It has a very tight hold on the rocks where it grows. It's also stiff - bristle like, not soft like HA. I'm thinking its a type of Cladophora... your opinion?
<Could be a Cladophora... or Bryopsis... or a Blue Green Algae attached/associated with it. Do you have access to a decent low power microscope? Do see/read on WWM re their use in algae identification. Bob Fenner>

Bryopsis?  5/8/11
Hey crew,
I was wondering if this sounded like Bryopsis to you (that rhymed, but oh well). I have a bunch of this green algae growing on my live sand, and whenever I disturb it by displacing the sand, long strands of it start floating around, still attached to a piece of sand at the base. I wasn't sure if they were Bryopsis because the pictures I saw for the most part looked something like --->->->--->->->--->->-> or
What I have looks like -|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-< .
It has the slightly thicker stem running up the middle with small hairs (not sure what to call them, sorry) sticking out perpendicular from the side at even intervals. Also, at the end it appears to fork off like a snakes tongue.
Is this enough to get an idea without a picture?
<Not me, no>
Just really wondering because if it is Bryopsis I'll have to get a Tuxedo Urchin temporarily I suppose. It keeps getting sucked up in the powerhead when I dislodge it so I have had to clean it daily.
Thank you very much as always,
<Perhaps a bit more searching, reading, seeing some other representative images. BobF>

Is Bryopsis safe for a FOWLR tank?   3/14/11
I have a more-or-less theoretical question about Bryopsis, so I'll avoid limiting it to any specific tank specs.
I've read most of the voluminous material here about Bryopsis, and the consensus seems to be that it's the Spawn of the Devil, and extreme measures to control it are justified.
But the complaints mostly revolve around it choking out corals and other sessile invertebrates, so I'm wondering if it's such a deadly curse for FOWLR tanks.
<Mmm, not so much>
Can a FOWLR person treat it pretty much like any other macro algae and watch it grow as it sucks up phosphate and nitrate?
Then harvest it occasionally to pull those nutrients out of the tank?
That might make it self-limiting, right?
<Yes as well>
Or am I missing a danger? Like, might it suddenly go sexual and nuke the tank? Some other hazard to letting it grow in a FOWLR tank?
<Not really... not "that" toxic, nor competitive>
<Welcome! Bob Fenner>
Re: Is Bryopsis safe for a FOWLR tank?   3/14/11
Bob - Ah, you've set my mind at ease! It really is pretty, at least for now. Thank you!
<Welcome Tim, BobF>

What's the best way to remove Bryopsis without stressing fish out?   5/3/10
Hi WWM Crew,
First, thanks so much for keeping the site online. You've provided invaluable advice over the years I've kept aquariums.
I recently set up a new (five weeks old now) 120 to replace my old 45 tall, and unfortunately it appears to be having a rather serious Bryopsis problem.
It doesn't seem to be growing much anymore, but it's not really going away either. I'm not really sure where the Bryopsis came from.
<Rock most likely; and conditions allowing/promoting. Only takes one spore... could "come in" w/ anything wet>
The tank has about 100 pounds of rock (and another 20# of rubble in the sump), probably 60# of which is from my old tank, which never had a Bryopsis problem. The non-live rock was cleaned (scrubbed, some
boiled, soaked in mild vinegar solution, and soaked in fresh RO/DI (0 TDS) to clean it off). The sand in the display tank was bagged dry Caribsea reef flakes and was rinsed in RO/DI water. The sand, rubble,
and huge Chaeto ball in my refugium came out of my old tank, and I have three mangroves as well. It runs GFO and carbon, and is set up for ozone and UV though I'm waiting on a new ORP probe before I
actually start with that. Ammonia, nitrites, and phosphate are all zero, nitrates are around 5-10 ppm if even that. Lighting is via a Tek eight bulb unit, which runs the center whitish lights for two hours per day, and the outer actinics for 11 (it will get more light once I get the algae under control). Skimmer is a H&S A150 and is working well. Flow consists of a Eheim 1262 return, two Korallia K3s (until my Vortechs arrive), a Magdrive 1800 closed loop (outlet behind rocks, it's only there to keep detritus from building up) and a MJ1200 with stream pump attachment. PH is 8.3'ish currently, and temperature is 82. Magnesium was a little low at 1150 last I checked. Alk is currently at 10'ish. I change 10g of water per week. Salt is Tropic
Marin and I don't dose anything except buffer in the top off water and Ca when needed.
It started growing before I had any livestock in the new tank (which was cycled using ammonia, not fish). I think what started it was a mix of sunlight coming through a window and hitting the tank, combined with a missing blenny to provide extra nutrition, and a skimmer that wasn't set up properly. I still have no idea where it came from. After it cycled I saw a little bit of green hairy algae and figured it was generic new tank GHA, so I went ahead and added my fish (smallish blue tang, five Chromis, and a recently purchased lawnmower blenny) over the space of a few days and bought a much larger cleanup crew. Some of my Zoanthids and a chalice coral are in there and are epoxied to the rocks.
Since I'm bugging you guys, it's obviously not generic GHA. I now have magnificent (for lack of a better word) clumps of 8" long streaming Bryopsis
<Streaming? Not a trait>
all over the place. It's not growing much anymore since I blocked the sunlight, fixed the skimmer, cut back on the lighting, and turned the refugium lights on 24/7; I assume it can't compete with the refugium for nutrients. The hermits, some of the snails, and the lawnmower blenny and tang will nibble at it when it's long and even eat it when it's short, but they're not putting much of a dent in it.
The fish all seem happy and healthy in the new tank.
I've heard conflicting advice as to what to do. I've already raised my magnesium back up to 1350'ish with Kent Tech-M and can keep going until it reaches 1600+ and try that, but I've heard it can kill invertebrates. Since I just moved the fish not too long ago, I'd rather not stress them out by doing anything drastic to the tank.
What, in your opinion, is the most effective and least stressful way of removing it? I've been told not to cut or yank it out since it can spread that way. I'm considering getting a Foxface or Rabbitfish since I don't have a huge bioload.
New Orleans
<Mmm, please read here: http://wetwebmedia.com/BryopsisF.htm
and the linked files above. Bob Fenner>

Bryopsis Shrimp/Algae Control 3/28/10
Hi all!
<Hello Nancy>
I am having a problem with what I believe to be Bryopsis in my 65g LPS/SPS Red Sea Max250. I also had a good amount of Hair Algae, and Cyano. I believe I have the hair finally under control, and have upped my 20% water changes to once a week /10 days which should take care of the Cyano (I hope). I was using reef snow, which I have stopped using for now, and have cut back to just a cap of Phytoplankton/week for my 2 Tridacna Croceas.
Before raising Magnesium, and/or buying a Calcium Reactor, I have been trying everything else to eradicate this awful algae, I have been manually removing it while siphoning during water changes, and have a Money Cowry, some Turbos, and a few Margarita Snails. I also have 2 Tuxedo Sea Urchins, but all together, aren't making a difference.
<Won't touch the stuff.>
I also added 2 Vortech pumps to add to water movement. I considered a Lawnmower Blenny, and a Tang,
<They won't touch it either.>
but I believe my tank is too small for a Tang, and I already keep a Banggai Cardinal, a Bellus Angel, Truncatus Anthias, Purple Dartfish, Green Bar Goby, Blue Mandarin, and a Yellow Striped Cleaner Goby. I'm not sure if I
have room for another fish.
<Nope, would not any more to begin with, you will just increase nutrients fueling the growth of the algae.>
The main reason for my note to you today, is that I saw a shrimp at my LFS that they call a Bryopsis Shrimp, and apparently its supposed to eat Bryopsis. I put it on hold, and have since, been looking all over the web,
and your site for more information on the safety and care of this little crustacean, but haven't come up with much. All I have seen, is an alternative name; Blue Shrimp, and a scientific name of Heteropeneus longimanus, and the fact that they are impressive jumpers!
<Yes, I've read reports about their jumping ability.>
I already have a Skunk Cleaner, and a Peppermint Shrimp. Would this Bryopsis Shrimp be a possible solution to my algae problem, or should I consider a Nudibranch, or borrowing a Sea Hare instead?
<I've only read one report where a dealer claims he saw the shrimp eating Bryopsis in his tank, and he also sold two to customers who claim the same. The problem I see here is that if the shrimp does eat the algae, it is just a method of control and will not get rid of it. I also doubt one shrimp is going to put much of a dent in the growth.>
Should I just cave in, and invest in my Reactor, raise the pH for a while, and keep it at that?
<I've read a few reports where raising the magnesium to well over 1500ppm was effective in eradicating the Bryopsis, but in doing so you are likely to have problems with calcium precipitating out of solution. As to the pH, I have read reports where raising the pH was effective.
You do not mention the use of a protein skimmer which will greatly reduce available nutrients/food for the algae. Have you read our FAQ's on Bryopsis control? If not, do read here.
Thanks so much for your help, and always super helpful site!
<You're welcome. James (Salty Dog)>

Hair Algae? Making Me Crazy/Algae Control/Jack Daniels If You Please 2/4/10
Hey Crew,
<Hello Chris>
I know you here it over and over but all of you are awesome.
<Thank you.>
I have never seen a sight with so much information and so helpful. I use your sight constantly. I started my first saltwater tank in May and now have 3 tanks.
My daughter and girlfriend and I love learning and caring for all of our new friends. The tank I need help with is our oldest one (only 9 months). It is a reef tank, 75 gallons with a 30 gallon sump. We have 4 actinics, 2 halides and at least 100 lbs of live rock. I check chemicals at least twice a week and always top off with RO. Ammonia and nitrite are always zero, pH is generally 8.4, alkalinity 8-9, CA 400-440 and temp 79-82. I battle nitrate now and then but in general it is around 5 almost never above 20. The tank has been pristine (I am probably one of the keepers you talk about that can’t stop messing with the tank) but I am now waging war against some type of hair algae, I think. It grows rapidly on any live rock that has light exposure that doesn’t already have a coral or anything living on it. I
have checked phosphate repeatedly but the test kit I have is very hard to tell color difference on.
<Yes, generally phosphate is absorbed by algae as soon as it forms. You likely wouldn't get a reading unless it was forming faster than the algae can absorb it.>
It seems like it is always at the lowest color. Yesterday I added a phosphate reactor and Phosban to the system. Whatever it is it creates a mat of brown particles that form in a mat over everything. It is concentrated more on the fibers of the algae though. I use a bulb syringe daily to break the mat apart and clean the rock.
<Mmm, go here, look anything similar to the pics? http://www.wetwebmedia.com/bluegralgae.htm>
The filtration removes them to the first particle filter which I change. In 24 hours it is all back and the hair gets longer. I looked at the brown seed like particles that form the mat under a microscope and they appear to move. It is green and brown and has what appears to be eye like spots. Is this algae or some type of worm and is it related to the hair or two separate issues?
<May be pods of some type.>
It is making me crazy and ruins the appearance of the tank.
Will the phosphate reactor solve the problem?
<Unlikely, a protein skimmer would do more for you here than anything else. You do not mention the use of one so I'll assume you do not have one. It appears you have excess nutrients in the water and with the presence of good
lighting as you have will accelerate the growth. Steps to eliminate/control the problem can be found in the links below.
I have attached a photo of the algae. You can see the brown green particles on the left under the clam in the algae.
<Not really resolved enough for me to see any detail, but it appears to be nuisance algae.>
The algae is dark green with a bluish streak at the center of the filament. I have read tons of your articles and Bobs book on invertebrates. I can’t find anything that specifically addresses my issue. Help!
<See/read all related info contained in the links above and implement the advice. This problem is not going to go away overnight, as it didn't start overnight. It will take time and patience. James (Salty Dog)>
<<Mmm, no... this is a Chlorophyte... Likely Bryopsis. Read here: http://wetwebmedia.com/BryopsisF.htm
and the linked files above. RMF>>

Re Hair Algae? Making Me Crazy/Algae Control/Jack Daniels If You Please 2/5/10
Wow you guys are amazing. Super fast response.
<You're welcome.>
This is the picture on the FAQ you sent me that looks most like what I have.
Here is another photo from my tank. Sorry couldn’t get a clear shot.
Is this Bryopsis or Derbesia. I couldn’t tell from the FAQ?
<Yours or the FAQ picture? Mr. Fenner believes what you have is Bryopsis.
Read FAQ's here for help/advice. http://www.wetwebmedia.com/grnalgcontfaqs4.htm>
Are the pods what new hair is growing from?
<No, and it was just a suggestion. Without actually seeing it/them makes it nearly impossible to ID.>
Should I continue the attack on them?
<On the algae, yes, implement what you have read and read above link.>
OK so a few more facts for you and then what I think my game plan should be. If you could just tell me if I am on the right path that would be great.
<As above.>
I do run a Super Skimmer. It produces about 3 inches of Skimmate per week.
<Cleaning the riser/reaction chamber every couple of days will increase efficiency of the skimmer.>
I also use a UV sterilizer that dumps into carbon media.
I have a Sohal, a Kohle <Kole>, two Percula Clowns, Foxface, Bicolor Pygmy Angel and a Niger Triggerfish. All are small less than two and half inches. I also have 3 shrimp and a Tridacna. Corals are Pulsing Xenia (over taking the tank) Frogspawn, various mushrooms and elephant ear.
<Too much load for this system which in turn promotes excess nutrients, and most of your fish will need larger quarters in the near future.>
I feed once a day 1 cube of Formula 2 and one cube of Formula B. I used to feed twice but have been trying to limit nutrients for over two months.
Should I feed less? They devour it in 2 minutes and still seem hungry. I am worried they aren’t getting enough.
<I wouldn't feed two cubes at once. Spread it out over three daily feedings.>
Should I switch them to flakes? Is this less nutrient input?
<Would be less nutritional. Frozen foods will generally produce more waste in the water unless rinsed in a net prior to feeding. You might give the New Life Spectrum Pellets a try. A very nutritional food with little waste, is all I feed.>
Rest of my plan, yes or no?
Switch out my actinics – 9 months old.
<I would not use this lighting for now, especially with four of them in a 75 gallon tank. Actinic lighting peaks in the mid 400nm range and can promote algae growth. There is enough blue present in your MH lamps to promote
photosynthesis for other light loving animals. If anything, cut it down to one or two actinics.>
Do I need to switch the halide bulbs also?
<I don't know, they are generally effective in the rated Kelvin temperature for a year.>
Decrease halide time from 8 hours to 6. (actinics run 12)
<Halides are fine, I'd decrease the actinic photoperiod to a couple of hours before the halides come on and turn back on for a couple of hours just before the halides turn off.
Remove the rock – again! And scrub in RO.
<No, do not do this, you will be killing other life present in the rock.>
Continue to blow off the pods daily with a bulb syringe.
What about raising the light unit higher? It is about 8 inches above the tank now.
<Is fine.>
Continue to use the phosphate reactor.
<Might as well, you bought it.>
Is this enough or should also try the pH increase and the ferric oxide?
<????. PhosBan is a synthetic ferric oxide.
Leave pH alone and read/act where you were sent.>
Again thank you!
<You're welcome. James (Salty Dog)>
Chris Terrels

Re Hair Algae? Making Me Crazy/Algae Control/Jack Daniels If You Please 2/5/10
Thanks James!
<You're welcome, Chris.>
Are you guys funded by sponsors, donations or both?
<A little of both, and I believe some may come out of Bob's wallet. What say you, Bob? We are strictly a non-profit organization, the crew's time is donated, no paychecks given out here.>
<<Not money from me, but perhaps its equivalent, time, effort. Most of the incoming monies are from commercial sponsors who believe in what we do (educating, inspiring their present, future customer base); and most outgoing is for content; principally our on-line 'zine. RMF>>
I would like to contribute to your cause if you are donation based.
<Great, and will be appreciated. Go to this link, scroll down to the bottom of the page where you will
see a donate tab. http://www.wetwebmedia.com/WWMAdminSubWebIndex/question_page.htm
James (Salty Dog)>
Chris Terrels

Bryopsis and lighting   1/31/2010
Hi crew
<Hi Jennifer>
I've been scouring your website for info on eliminating Bryopsis.
I've been fighting this pain for over a 1 year now. Quick facts: 55 gal w/ 30 gal refugium, Chaeto in the refugium, AquaC Remora skimmer, R/O water, 80# live rock, 3 power heads, 130 watts of power compact lights run for 12
hours, 1 clown, 1 royal gramma, 1 coral beauty, 1 Hawkfish, 1 Florida orange starfish, 1 sleeper goby, scarlet leg crabs, green star polyps, mushrooms.
<Sounds nice!>
I feed fish 1x/day with ground shrimp, crab with Selcon added.
<Hmm, is this a home made mixture? A source>
I do weekly water changes (15-20 gal), change filter media <? what is this?
Could be a factor also> weekly. I used to scrub the rocks but don't anymore since I discovered how many critters (amphipods, starfish, etc) were on them. Water parameters are at 0 (tested a couple of days ago).
<Which water parameters? Better numbers please, so that a 'feel' for the system can be had>
Here are the questions:
1. Could the lighting be contributing to the algae? Reason I ask is I've taken a couple of rocks that were covered and put them in the refugium. The blue leg crabs eat the algae. I've left the rocks in there for months and no more algae grows on it. As soon as I put it in the display tank the algae grows back.
<Algae does need light of course, but you should be able to light your system w/out having excessive growth. When did you last change your bulbs?>
2. I read on your website that increasing the pH to 8.5 for 3 weeks will eliminate the algae.
<Have read this as well, but increasing pH to 8.5 and keeping it there for 3 weeks (especially overnight) is next to impossible in most home systems.
My experience also tells me that fiddling around with your water chemistry is a bad idea>.
Would this hurt my inverts? Specifically the starfish. 3. Should I add another protein skimmer? The Aqua C doesn't put out as much skimmate as I thought it would or even as much as my old Coralife skimmer did.
<Mmm, could you not run your old one as well for a while? Why did you change if your old one was performing?>
I've been thinking about changing out the lighting to T5. I live in Florida and have enough problems keeping the temp down in the summer. I think metal halides would make it worse.
<Changing the lights could have an effect, but it is not worth the investment just for this, as there is something else amiss w/ your system here. Older bulbs do lean towards spectrums that favor algae, so if you have not replaced them for 6 months or more then you could try this, but that is as far as I would go with the lights. I think you need to persevere here with the maintenance, pulling it out, turkey basting rocks, water changes, maybe some GFO for a while, but since you have not given me any numbers for your tests it is difficult to comment further>.
ANY piece of advice would be welcome!
<Try here & Related FAQ's, there is a lot of info on this:
Thank you

Re: 30/01/10 Bryopsis and lighting 2/1/2010
Hi Simon,
<Hi Jennifer>
Thanks for the quick response! Answers to your questions: Water parameters: NH3/NH4 is 0, PO<4> is 0
<Not likely, is being sequestered by the Bryopsis, and there should be ‘some’ here – is an essential nutrient>, NO3 is 0
<Should be ‘some’ here as well>, NO2 is 0, pH is 8.3, Calcium is 400. Their food is homemade but I've only been doing that for 2 weeks,
<I would cease this until the algae is under control>
prior to that I was using Mysis shrimp (thawed and rinsed). I change the bulbs out every 6 months. In reference to the "filter media" I was referring to the pads or filters in the 1st part of the refugium.
<I would remove these – a nutrient ‘sink’>
I changed the protein skimmer because I didn't think and was told that it wasn't producing enough skimmate.
<Mmmm, was your system balanced at the time? If it ain’t broke...>
The research I did said the AquaC was one of the most recommended. Yes, I could put the old skimmer in as well.
<I would for the minute>
You suggested "GFO"..I'm not quite sure what that is.
<Granular Ferric Oxide, http://reefkeeping.com/issues/2004-11/rhf/index.php but if your phosphate is testing low then this might not be a good idea, at least for the long term. Some Po4 is necessary for life>.
I will say that when I use a Polyfilter or a micron pad they come out dark brown within a week which suggests heavy amount of dissolved organics. Would you recommend adding the other protein skimmer?
<Yes I would – are you growing any competing algaes (Chaetomorpha) in a refugium at all here?>
Thanks Simon! Jennifer
<No problem! Simon>

Bryopsis - Possible/Algae Control 11/29/09
Bob and Crew ---
I recently set up a new system that I bought from a friend of mine, that was already established. Everything in the system was moved over without much incident. I did not use the old water from his system, nor his sand. The sand that I used is the CaribSea sand that you can buy at any LFS and made up some new fresh water for the system. The rock in the tank was all of the rock from his system.
While, I know I will still go through some "new tank" stages, I won't hit them all. I.e. not much of a cycle, because we kept his rock wet and etc.
However, I am going through this wonderful 'new system' stage, where I am getting this beautiful algae growth. Now, I know some of the algae that I am experiencing is green hair algae ... I always see something a little different. I, unfortunately am unable to get a photo at this time (not one in detail anyways :( ). I have noticed I have a lot of green algae sticking to my glass, upon further inspection, it looks like a leaf/feather. Now, all of my homework and research tells me it is Bryopsis, unfortunately ...
I'm having a hard time finding the exact or a really good picture of Bryopsis. In your great library of photos, do you have a good photo of Bryopsis?
<Are many photos here to help you ID.
Also, if it is Bryopsis .. I have read it is a little harder to
get rid of than most other algaes. With that said, what would you recommend for the extermination of such?
<Lawnmower and Bi-Colored Blennies have been known to eat this along with Diadema Urchins. Sadly, there are not too many herbivores that like this stuff if indeed Bryopsis is what it is. I suggest reading here and related articles/FAQ's linked in the header.
I have tested all my levels in my system, and they are all coming back negative.
Ammonia - 0
Nitrates - 0 (I know obviously there has to be some for it to grow as its nutrients are No3 and Phosphates)
<Yes, being taken in by the nuisance algae.>
Phosphates - assuming 0 (I unfortunately can't test it at this moment in time, because ... I can't find my test :( )
Nitrites - 0
Tank specifications:
40gal breeder
1- 175w Iwaki MH w/ Blueline ballast
2 - 39w 24inch T5'2 (super blue)
Pacific Coast Skimmer rated up to 100gal
Quiet One 2200 for the return
Vortech MP10
I do drip pickling lime into the system, to help keep the parameters stable.
<I have recently read that elevating the levels of magnesium from the normal range (1,280 ppm) to 1,500 – 1,600 ppm will greatly help in eradicating Bryopsis. The theory behind this is that the magnesium stops the photosynthetic processes in the Bryopsis, but does this without affecting other desirable macros. There are also some reports that suspect elevated levels of magnesium can kill desirable invertebrates, but I have never read any documented proof of such. Bob may give his input here in this regard.><<Mmm, nope. You've stated admirably more than I know. RMF>>
<You're welcome. James (Salty Dog)>
Shawnda Etgen

Re: Bryopsis Control - MgCl2 Dosing?  11/15/09
Thanks for your help.
I've set up a little experiment to see what concentrations do this trick and what brands work.
Hoping that simple Epsom salt accomplishes this so people can save the money for better things. One control with only weeds nothing else, one with Kent tech M, one with Aquavitro ions, and one with Epsom salt. Increasing the concentrations slowly until I notice a difference. Doing this in Tupperware with minijet's and some LR. Keeping next to a window. Granted its not the typical environment but should provide some useful information. I guess MgCl2 Is very useful for many things.
<Yes... has many common applications...>
Anyhow will let you know the results.
Also I was reading through some of the nitrate control FAQ's and came across a section where you said 'It could be argued that massive 25% or above water changes can cause more harm than good'.
<Yes; too much instability is often introduced thus. One must be assured of good water quality in what is being replaced>
Can't find any more background information on that. I change the entire volume of my tank 1.5 over each month for nutrient export.
Seems to be doing the job well since nothing else works. I have not tried a DSB for aesthetic reasons but that's the last resort.
<Best to "remote" this/these... in a sump, refugium... not in main displays in general>
I never really liked the idea of 'maxing out' my biological filter. And if something happened to the bacteria for some reason it would cause the tank to crash and all of the nutrients to be released.. Correct?
<Can possibly>
So basically my question is why would massive water changes cause more harm than excessive nutrients would?
<See above>
Also what is your opinion on the new TC type of Deltec Skimmers? I am looking into upgrading to a better skimmer.
<Very nice, though expensive, units>
There is some info on them.. As I am not sure if they have been released yet.
<I think just>
Thank You,
<Thank you Cass. BobF>

Should I rinse frozen food to remove phosphates? 8/2/09
<Hi Jim, Jessy here>
I'm hoping you can help resolve what has become a HUGE disagreement between my wife and I. We have two tanks: one 65 gallon that houses our seahorses, that we've had for about three years, and one 210 gallon fairly new reef tank with numerous fish (9 chromis, 2 clownfish, 1 flame Hawkfish, 1 yellow tang, 1 lawnmower blenny, 1 rusty angel, and 1 Banggai cardinal) established about 3 months ago. The seahorse tank has a chronic massive problem with nuisance hair algae. I very much want to avoid having this same problem with the reef tank. Both tanks are regularly fed various frozen foods:
San Francisco Bay brand Marine Cuisine, Spirulina- and Omega3-enriched brine shrimp, and various brands of frozen mysis. The fundamental question that is the basis of our disagreement is whether or not it is important and beneficial to rinse these frozen foods after thawing them. As the person who has to clean the algae from the glass, rockwork, and every other surface of the seahorse tank, and the person who does all of the testing for nitrates and phosphates, and regularly replaces the phosphate adsorption media, I maintain that it is important to rinse the thawed frozen food in order to remove as much phosphate as possible before feeding the fish and seahorses. As the person who regularly feeds the fish and seahorses, my wife maintains that the "juice" from the frozen food contains important nutrients, and that rinsing the thawed food would remove essential nutrition that was specifically added by the manufacturer for the benefit of the fishes and other filter-feeding creatures in the tanks. We recently asked the local "expert" at our LFS, who said he personally doesn't rinse these types of frozen foods, because it helps feed the filter feeders. I'm hoping that you can help settle this disagreement we're having. I've been unable to get my wife to take the time to actually read the numerous sources I've located online, all of which state the importance of rinsing thawed frozen foods to remove phosphates. What does wetwebmedia.com have to say on this issue? To clarify: not asking for marital advice, just whether to rinse or not to rinse!
Thanks in advance,
<Absolutely yes, you should be rinsing your frozen food. You can do something as simple as putting it in a brine shrimp net and holding it under cold tap water to thaw and rinse it at the same time. The things that
you are rinsing off are mostly the binding agents for the frozen food... and yes it can lead to phosphate problems. Your filter feeders will benefit much more from a dose of phytoplankton or Cyclopeeze than they will from the little particles found in that frozen mush. I'm a huge proponent of PE Mysis, (who also suggest to rinse their product) and I noticed that a lot of the pieces and parts that get rinsed off are the lighter scrap, like tails and legs. When added to the tank, none of the fish even attempt to eat those pieces, passing them by for the meaty portions. I said all that to say, that by not rinsing you're putting unnecessary binding agents in your tank and particles of "food" that are just going to go unused and add to a high nutrient problem. By the way, with the hair algae the best way to combat it is to remove it with your fingers (yes elbow grease is
unavoidable) and I've always had success with large turbo snails. Every time you walk past the tank and they are not eating a patch, just pick them up and plop them on top of it. With continued water quality monitoring and a little bit of time, every hair algae problem treated that way has been solved for me. Now Bryopsis, is a whole other ball of wax. Make sure you're identifying it correctly. Hope that helps. Jessy>

Re: Should I rinse frozen food to remove phosphates? Now Bryopsis, Hair alg. control  8/3/09
Thank you, Jessy, for your reply. Regarding identification: I thought Bryopsis was a type of hair algae. Three questions: 1) What type of  hair algae were you describing the relatively easy control of? 2) How can I tell that one apart from Bryopsis? 3) What do I do if I have Bryopsis?
<I'm talking about the algae referred to as "hair algae"
http://www.wetwebmedia.com/grnalgcontfaqs4.htm viewed/discussed here. The
best way to tell if you have Bryopsis is to look at the strands of algae.
For me, Bryopsis always looked like a little fern. Basically a central shaft with smaller hairs branching off of each blade. As opposed to hair algae that just looks like thin green hair. If you have Bryopsis, I suggest
doing a search on WWM for more info, I know there is a vast amount of it.
Two ways I've heard of conquering it were raising the magnesium levels in the water, or the use of a ruby lettuce Nudi. If you do go with a Nudi, please make sure that you cover all power heads because they will find them and get hurt, and also be prepared to pass it along to someone else in need after all the algae is gone because it will die in your tank otherwise.
Regards, Jessy>

Re: brittle star question, beh., and alg./Bryopsis control...
Thank you.
I will try to get a video to verify
<I look forward to seeing it.>
and I also have another question concerning one of my other tanks
it has a bunch of this green algae Im am pretty sure that it is Bryopsis because it looks like small palm trees and it is taking over some of my corals and my rock is covered and I can't seen to get rid of it. Is there any suggestions?
Nitrates 0 nitrites 0 phosphate 0 PH 8.0
<Yes, I think you will find these articles helpful. Please read here:
Hope this is helpful.
Mich><<Try some small species of Cowries... C. moneta, C. caputserpentis... RMF>>

Derbesia eradication  11/17/08
Welcome Back to the States Bob!
I am sure you had a enjoyable time.
Can't wait to see some photos!
After much research on the topic of Derbesia eradication I have found the following info on species that may chow on it:
It is seemingly apparent in Australia that the sea hare species:
Dolabella eats a variety of nuisance algae such as :Bryopsis, bubble algae, some hair algae but not feather Caulerpa.
Bryopsis feeders are ( herbivorous sacoglossan):
Elysis virdis(Britain) , Placids dendritica, limaponita capitata,
Australian: Elysia ornata , Elysia rufescens
Herbivorous Snail: Scutus, Cypraea annulus, limpet( I used to have hundreds of limpets)
I contemplated your recommendations for my 15 y/o tank, but just did not want to go that route at this time.
I respectfully request your opinion if they would do the job and if and where can I purchase them.
Also this sight link offers a photo of the Slug that Wes just sent to you today.
Also some camera phone photos of Greenwich, CT.
Thank you Bob
Donna W. Hackert
<Thank you Donna... will share, post. BobF in Cozumel>

Re: Derbesia control  11/17/2008
Hello Bob,
You forgot to answer with your opinions of these creatures- are they chow hounds for Derbesia??
and where can I purchase. I cannot locate anywhere in this country!!
<Most all listed can be found from time to time... I'd ask your LFS to special order... and/or look to Dr.s Foster & Smith, Marine Center...>
Any assistance would be appreciated.
Thank you Bob,
<None listed are consistent for sure predators/eaters of Derbesia spp. BobF>

A little identification help please – 10/13/08
Hello crew,
I've had this algae/plant growing in my 150 reef tank for quite a while. Very pleasant looking but starting to spread more than I'd like.
<Mmm, yes>
Neither my tang, blennies, hermits or snails seem to munch on it.
<Not very palatable... to much of anybody>
Could you help identify it
<Mmm, likely a species of Derbesia>
for me and suggest a way to lessen the spreading.
<See WWM, the Net re this name... and likely Bryopsis... both "treated" about the same... best by competition, denial of nutrients... a few approaches to these...>
(I have multiple corals so limiting the lighting would probably have to be minimal). I'm running the PhosBan reactor so there's not a phosphate problem.
Also, I've worked with you (Bob) before so my water quality is "up to snuff." Over the past few months I've replaced all lights, drained water from frozen food and done weekly water changes to keep nitrates very limited.
Thank you,
Greg Esposito
<If there's room, you might try other predator groups... maybe a Siganid... S. stellatus if you can find one... BobF>


A little identification help please - follow-up... Grn. alg. contr.  10/15/08
Hello again Bob,
Thanks for the info below regarding the Bryopsis/Derbesia problem. I've done more research on your site trying to get a good handle on the specie and ways to eliminate/control it.
<Can be persistent!>
I wanted to run by you what the LFS just told me when I stopped in to get a fresh batch of C-Balance and look for Caulerpa.
<Mmm... a bit to say re both... the Wilkens, nee TLF product is fine, but I'd definitely pass on this genus of Chlorophyte (folks do try to use mainly C. verticillata to outcompete Bryopsis et al. for you browsers)... reasons gone over and over on WWM>
First, let me say that my LFS (The Living Sea) has been around for quite some time and I've generally found the owners to be pretty knowledgeable.
<I also have heard many good anecdotes re>
That said, I asked them today if they were familiar with the algae to which they grimaced and quickly said, "you'll never get rid of that algae"...
<Heeeeeee! Man, that's a dire statement!>
"we've never found anything that would eat that"..."it will be the last thing to die in your tank."
<Along with terrestrial cockroaches? Heee!>
I left the store with the options of:
1) Take out the affected rock, wash it and scrape off the first layer in hopes of getting it all. But, if I miss one strand of the Bryopsis, it will all grow back.
<May be>
2) Take out the affected rock and let it dry/die.
<Another approach>
3) Leave the tank "as is" and expect to have to shut the whole
thing down if the algae spreads.
Are things that bleak?
<Mmm, nah>
My 150 was born in October of 2006 complete with Current Orbit Halides/Actinic T-5 lighting system, protein skimmer, PhosBan reactor, UV sterilizer and chiller. I run carbon, too, and my refugium is stocked with Chaetomorpha sp. per your advice. 35 gallon water changes are done weekly or bi-weekly....mostly bi-weekly. I do have a R.O. system, make my water and perform all tank maintenance.
Salinity: 1.025
Nitrates: 10 or less
Phosphates: 0
Ph: 8.2 to 8.4
Alkalinity: 6.5 to 7
Calcium: 440 to 460
Temp: 75 to 77
Actinics run 11am to 8pm and halides run 12pm to 7pm. Refugium lights on from 8pm to 11am.
Stock: Most of my corals are large (8 to 12 inches) including Leather, Elegance, Frogspawn, Bubble and Toadstool. 6 inch Sail fin tang, 4 inch Copper banded Butterfly, 2 medium Chromis, Male and Female Maroon clowns, Lyre tail Anthias and 2 Lawnmower Blennies. Also, a lot more snails and hermit crabs than you would prefer...as you've told me before.
<Mmm, I'd still try the Siganid, possibly some Sacoglossan: search: what eats Bryopsis>
I've attached a picture of my tank, too.
<Ahh! Very nice! What a beautiful setting altogether! Something right out of "Beautiful Aquariums, Homes and Gardens" magazine!>
Thanks so much!
Greg Esposito
<Don't despair Greg... I've seen the end of the world... this isn't it. Bob Fenner>

A little identification help please - follow-up 10/15/08
Whoops...also forget to mention I have 6 maxi-jet 1200 powerheads hooked up to a Wavemaster machine.
<With such a fancy setting, I thought you'd likely be vested in Tunzes! B>
LOL. Maybe I should add Tunzes as our fish and corals deserve the very best we can offer them. Thanks for the guidance, as always.
<Welcome my friend. BobF>

Bryopsis control, reading   6/27/08
Hello. I have a recurring Bryopsis problem, which I've had ever since adding Fiji rock to my existing aqua cultured Florida Gulph rock last
summer. I have a 12 g , keep a royal Gramma and a Sixline wrasse, have a bare bottom, use filter floss and ChemiPure in this all-in-one's chambers,
do weekly water/filter floss changes using distilled water, feed remarkably light, once daily, and run the 48w PC's for 12hrs/day. Bulbs are new. Flow is a MJ 900. At this point I've tried everything to get rid of it, and the only thing that works to kill it is dosing magnesium, which my Ricordeas and polyps don't seem to enjoy too much.
<Uh, no>
I can't imagine where the stuff's getting the nutrients to be as rampant as it is,
<Is a successful competitor for... from foods, water...>
as I'm as diligent as ever in maintaining the tank. Like I said, i can't help to be suspicious, as I never had any problem with Bryopsis before adding the Fiji rock, though I had a clump or two of GHA here and there, but nothing like this--HELP!
Thanks a lot.
<... the few general approaches to this pesky Green Algae are gone over and over on WWM... nutrient deprivation, competition and predation are the broad means... Read here: http://wetwebmedia.com/WWMAdminSubWebIndex/question_page.htm
put in the terms: "Bryopsis Control" and read the cached views. BobF>

Activated Carbon and Magnesium... Bryopsis control   3/12/08
I've been trying to eliminate Bryopsis in my 75 gal tank (plus a 20 gal refugium, so total gal=95) by elevating Mg (using a crystal magnesium supplement sold on Marine Depot),
<Mmm, this won't do it...>
but even after adding 1 cup (estimate 50-100gm), the Mg measurement stays the same (1300ppm using ELOS Mg test kit). I have activated carbon in a mesh bag connected to the overflow feeding into my sump/refugium, have been overskimming (24/7), <Neither will these>
cleaning the skimmer every other day (getting good skimmate production). Is it possible the activated carbon is removing the added Magnesium?
I thought it might, but haven't found a lot strictly saying this. Or is it that I must add Mg until alkalinity stops fighting the Mg level ?
<? No...>
.(pardon me if my chemistry is wrong here, which is why I'd rather ask that do more at this point.) I THINK that the Bryopsis started in the main tank when I removed a large clump of red macroalgae-Rhodophyton 'red on rock'-) which I had in the main tank in the early summer of 2007 (and I am thinking I should replace now- gave it to friend in trade for rock).
All other chemistries have been good (pH 8.4, Ca 375ppm, alkalinity 176ppm,ammnoinia, nitrite, nitrate's all 0; tested RO/DI water for phosphate=0; spec. grav=1.025 to1.026. Tank has 1 clown, 1 yellow Tang, 1 solar wrasse, 1 lawnmower blenny (that eats Nori or shrimp only); 1 open brain coral, some Xenia, and a small patch of zoos. I have been vigilant about overfeeding (I only chop fresh raw shrimp or clam, and feed making sure that most is eaten). Refugium has Chaetomorpha, harvested monthly (though I see a huge increase in growth/spread of Bryopsis in main tank when I do harvest).
I know messing w/chemistry may not be the best resort, but figure this is a good learning experience as long as I am careful about it. I wonder if perhaps the macroalgae that used to be in the main tank was effectively exporting much of the nutrients. I thought the Chaeto in the 'fuge would have continued the job. It probably is I think, just not as effectively as the Bryopsis in the main tank does, and I note that the Bryopsis grows much faster than the fuge's Chaeto.
Sorry to ramble, I've a bit of a cold and am resorting to whisky to ease the pain. Any advice would be much appreciated!
Best Regards
<Mmm, you could use Kalk or other relatively safe alkalizing agent to temporarily boost the pH (to about 8.6) to precipitate out essential soluble phosphate... But other methods (predation, competition) are much more useful long-term... Try here: http://wetwebmedia.com/WWMAdminSubWebIndex/question_page.htm
... the search tool... with the terms: "Bryopsis Control"....
Bob Fenner>

Green gloom 1/17/08
WWM Crew,
Thanks a million for all the great information on your site. I have learned so much! I've been searching for quite a while and can t seem to find an answer to my specific situation and it is driving me insane. My tank was going really well, I have 2 fire clowns, a cleaner shrimp and some snails along with a frogspawn, an open brain coral and a small frag of what I thought was called cotton candy but it is a branching coral with pink polyps. I also have an assortment of snails and some hermit crabs. I really want to get more corals and maybe a tridacnid or two but I m having problems with a single-celled Protist that dies off some at night so my water is a little clearer in the morning but by late afternoon it is really cloudy and greenish.
I m a chemistry teacher so I took some water to school and looked at it under a semi-decent (public school teacher that is) microscope. I found a high concentration of single celled organisms that are quite motile. With the scope I have I couldn't t get better information than this. I could see they had chloroplasts but I couldn't tell for sure if they had cilia or flagella. They didn't have the symmetry of diatoms for sure.
<Which, Bacillariophyta, are non-motile>
So I ve had this going on for about 2 months. I ve been trying to ride it out but it is not improving at all. My livestock is doing ok, but the corals are not expanding like normal and I m not seeing any growth at all. I have tried several things: first I tried leaving the lights off for about a week but had to abandon this when my corals started looking pretty bad. I ve changed my carbon (I use Chemi-pure) and even added more. I ve added a Polyfilter which is not really changing color like it should if it is absorbing nutrients, etc. The closest thing I ve done has been to do several water changes in a row (I have a few 5 gallon jugs I use, so I change 5 gallons at a time). By this I mean I went through 20 gallons of water in my 24 gallon tank! How many water changes in what sort of time frame is too much?
<Mmm, may not solve, change this situation at all... these organisms are likely able to reproduce at a rapid rate>
The next day it looked really good for a few hours each morning but has since gone back to being pretty much awful.
On to tank parameters | I have an Aquapod-24 with pretty wimpy circulation as I have learned the last few days reading on your site. I added an AquaC Remora skimmer 2 weeks ago (before that I had no skimmer) which, I ve now learned from reading your site, ought to have been the first thing I bought. I have live rock but I know I only bought about half of the weight I ve seen recommended per gallon.
<Increasing this may "do it">
The tank has been up for almost a year now and I have learned the hard way several times about additives, etc. (Being a chemist I thought I could control everything | wow was I stupid! A biological system like this is fantastically complex, which makes it so interesting to me) I have gotten my water parameters pretty good now I think: morning pH is about 8.4 and evening pH is usually around 8.6. dKH is 9, ammonia/um, nitrite and nitrates are all 0. I keep the temperature at a pretty steady 25 Celsius.
I ve thought about adding more live rock and live sand (unfortunately I don t have a quarantine) and I would like to stock more invertebrates but I don t want to spend the money on, or take the life from, any critters until I get this resolved. I do plan to add a powerhead in the next day or two.
Your help on this will be immensely appreciated!
-Craig Fox
<Well... you could "force" the die-back of the Protists... chemically or physically... a "motor-boat" mentality/approach... but I would go the "sail-boat" or motor-sailor route and add the new LR and LS and be patient at this point... I do hope you stay in the hobby long and well enough to "graduate" to a larger system... and that we have more adventures together. Bob Fenner>

Re: Green Gloom 1/29/08
Thanks Bob (and crew; you're all awesome),
<Welcome Craig>
Thank you so much for your advice, info and encouragement. I too can't wait to get a nice, reasonably sized system. As far as your advice to sail as opposed to motor boat approach, I'm going to take the sailboat approach.
<Ah, good. This is best>
I doubled the amount of live rock and I added an AquaClear 70 powerhead. Holy cow... my clownfish and shrimp and frogspawn have never looked so happy! The Protist bloom seems to be very slowly getting better. Also, by adding more live-rock I have some new cool Polychaetes, polyps and super tiny mollusks.
So I thank you again for having such a potent resource for us trying this hobby. There is so much beauty and learning to be had, its great!
<Yes my friend. It is indeed a wonderful world. BobF>

Bryopsis, control  1/5/08
I have Bryopsis growing in my reef tank and I want it gone. I tried a of search WWM to find how to remove Bryopsis but I came up with nothing.
What is the best way to remove this from my tank?
<Just like any other algae, manually to the extent possible and nutrient control.>
I run PolyFilter and Purigen and carbon on the tank (nano cube HQI 28 gal.) and use the skimmer that came with the tank.
<No real advantage to running all three chemical media.>
I feed DT 3x's a week for the Acros and clam that I have.
<How much? It can contribute.>
The fish are feed one small meal per day.
<Be sure it is all consumed.>
I have dwarf hermits and turbo plus a few other species of snails. I do weekly 10% water changes.
<Could be helpful to increase this on a tank this size.>
All my parameters are where they belong except my Ca, which is a little high, but I am not adding anymore and it will come down with the water changes.
<Nitrate is likely being consumed by the algae, keeping levels low.>
The tank is kept at 75*.
I have zoos, mushrooms, polyps, leathers and Acros in the tank plus 4 small fish and a pep. shrimp.
Can you tell me if Bryopsis is macro or micro algae?
Thank you for your help. You guys are the best!
<I do encourage you to read through the FAQ’s on algae control. The same factors that fuel other algaes are feeding your problem. Welcome, good luck, Scott V.>

TDS and algae 11/24/07
Hi there. <Hello.> I just measured the TDS of my source water (run through my relatively new Coralife 3 stage RO unit) at 17 TDS. Could this in itself be the cause of an ongoing problem with GHA and Bryopsis??
<Probably not, a TDS of 17 out of an RO is not too bad.>
Being that I have tried to remedy the problem in every other possible way (with the exception of using antibiotics),
<Wouldn’t help if it is algae.>
I was banking on this being the explanation. Before I had a TDS meter to know for sure, and was actually expecting the reading to be a lot higher. FYI, my tank is 65G sumpless, mixed reef, Nitrates 0, Phosphates 0, PH 8.4, 5 small fish, Aqua C Remora, Aqua Clear HOB running carbon (changed monthly), MJ1200x2. Any thoughts on this would be appreciated.
<You may want to test your makeup water directly for nitrate and phosphate after you have mixed the salt. Any mechanical filtration in the HOB should be cleaned at least once a week; detritus in it will raise your nitrate and feed your algae. Feed sparingly and make sure your water flow is keeping things mixed up (no settling). Please read through the website on substrates, they can also pose issues regarding nitrate and algae. Just keep testing and searching, you will find the source. Welcome, good luck, Scott V.>

Bryopsis Success!  10/20/07
I have been reading many of the horror stories about Bryopsis online on your site and others. I had my own nightmare with the evil weed. I am writing to share my pathway to success with your other readers. Hopefully they will benefit.
My Bryopsis journey actually started with a major system collapse. I have been at this for some time and have grown corals and fish successfully to the point that I regularly trade my healthy specimens back in with my LFS when they outgrow my system.
I'm not really sure what went wrong, and that's not the topic here. But after the collapse of almost all of my corals, I returned my still healthy fish to the store, determined to start out fresh.
This was when the Bryopsis started growing. At first small patches. I didn't really know what it was at first, and thought it was innocuous enough. However, the next thing I knew it was growing everywhere, and fast!
I started with trying to scrub the live rock. This worked for one week each time, afterwards the stuff came back as if nothing had been done. Failure.
I spent several months over the summer trying other things and getting more and more discouraged. Nothing seemed to work
After doing more reading online, I decided to try a "throw everything at it approach." This was expensive, but it worked.
First, my system:
75 gallons with 29 gallon sump (sump has 55w power compact for light)
Mag 7 return
Two Seio 670s for internal water circulation
Orbit Current light with 2 150w MH and 2 96 power compact actinics
Two CPR Urchin protein skimmers
1 AquaClear box filter (holds the PolyFilter and carbon)
Carbon, PolyFilter, PhosBan
1 15w UV with mag 2 pump (too much pump)
1/3 HP Prime USA coil chiller / with heaters tied in (dual temp control holds 77 degrees +- one degree all of the time)
Here's what I added / changed to get rid of the Bryopsis:
1. Bought an RO/ De-ion system, did six 20 gal water changes to remove all "old" water - our untreated local water is full of phosphates
2. Bought an 80 gph pump for the UV to slow down water flow and make it more effective
3. I had a small amount of direct sun that hit the tank at certain times of the day - I put up a screen to keep the sun off the tank ( less light, less algae)
4. From GARF.org bought a "janitor clean up kit" lots and lots of snails and crabs
5. Bought a small Foxface tang and a Tomini tang (very similar to Kole tangs) - by the way, the Tomini is a very cool tang AND really seems to eat the algae.
6. Bought the two largest Koralias (I think they are #4s) and set them on a 2 way ocean pulse wave maker gizmo to alternate at 60 second intervals (running the two Koralias together, along with the two Seios is simply too much water movement). They are located facing each other on opposite ends of the tank, Alternating these large water movers seems to have had a major positive effect on the entire system. I never used to be a wave maker fan, now I am.
7. Last but not least, I went back in and took all live rock with any Bryopsis on it and scrubbed it thoroughly in tank water from the system (then threw out the tank water used to clean the rock) I learned that if you are going to scrub the rock, you MUST do it outside the tank. Scrubbed off algae quickly re-establishes.
Within two days - all Bryopsis gone. I don't mean most of it was gone, I mean ALL of it was gone.
Tank looks spotless, rock almost looks sandblasted, coral not only living but growing faster than I have ever seen it grow As I said this was not cheap. Total dollar cost was probably $350, not counting the GARF critters and two tangs.
All of the "cures" listed above were gleaned from simply reading about other people's experience, the difference was, I did all of them together. The good news and the bad news about that is that it is now impossible to say if any one alone would have worked. I can only state that together, at least for me, they were very successful.
Frankly all of the above took some dedication, money and time. But it was a small price to pay for saving my interest in the hobby. I really was ready to throw in the towel. I have read other postings online from people who were ready to give up. That would be a shame, when there is a cure other than putting the tank in the garage. If any of your readers can get some benefit from my experience, this was worth the time it took to write it.
I would be curious to hear your thoughts.
Scott Erickson
<I count all your efforts taken separately to be useful... and together... Insurmountable as a cure in redirecting the mix of life here. Congrats! Bob Fenner>

Bryopsis Problems  8/14/07
Hello guys,
I really enjoy your site and everything you do for us!! My problem lies within my newly setup 55 g reef tank. The specs are as follows: 60 lbs of LR, 60lbs of LS, aqua c remora w/MJ 1200, and 500+ gph circulation within. I am having a serious breakout of Bryopsis, a little bit came on some of my LR. My parameters are as follows: pH 8.2, Nitrite 0, Nitrate 0, Ammonia 0, Alkalinity 140, Phosphate 0, Calcium 320, SG 1.025, and Temp 79 F. I recently removed my canister filter thinking that was the cause of my growth. I did have a 5 Meq/l reading of Nitrates, when I ran with the canister. So I did eliminate that, although I doubt that was all of the cause.
<I agree>
I use RO water and have tested it for Nitrites, Nitrates, and Phosphates all Zero readings.
<May be being absorbed/taken up by the pest algae... such point to point non-thinking is what Americans seem to believe re "terrorist production">
I just mixed up a fresh batch of water, I will be testing that tomorrow for the same 3 things to see if it my salt mix that has something that is feeding this stuff. I use Instant Ocean salt.
<A good brand... well, used to be... consistently>
I cant seem to find what is my cause.... Would an investment in a phosphate remover do any good?
<Possibly... but your other life likely need HPO4...>
I should add my livestock- 1 black ocellaris clown, 1 skunk cleaner, 2 peppermints, 1 emerald, 4 snails, 5 blue leg hermit, organ pipe coral. I do feed daily but only my clown and its direct feeding, the shrimp get the rest . I also am very good at performing weekly routine maintenance, water changes, manual removal of algaes, syphon sand, and cleaning skimmer.
The main reason I am asking this is my Organ Pipe Coral is now being over run by Bryopsis. The algae is very thick and covering 1/4 of this coral. I have increased flow a bit near it, but doesn't seem to help. The 1/4 that is covered never opens its polyps. This is a shame because I rescued this from a LFS in bad shape, a lot of die off. It was just starting to grow new polyps and look lusher so to speak. Anything I can do here? Thank you for your time in this matter! Brad
<Perhaps a Ctenochaetus, Mithraculus... Definitely the use of a refugium with DSB, macroalgal culture... Please read here: http://www.wetwebmedia.com/greenalgcontfaqs.htm
and the linked files above... to gain an understanding of what your options are, may be here. Bob Fenner>

Elysia viridis. Looking For A Bryopsis Grazer - 05/06/07
Good Morning all,
I have been working on a Bryopsis problem for a while now and have been doing regular water changes to combat the situation.
<<Have you looked through our info re nuisance algae?  Raising your system's pH to 8.5/8.6 and keeping it there for several weeks has shown anecdotal proof of helping to eliminate this pest alga>>
My battle has lead me to research additional means.
I have found that a sea slug of the order Sacoglossa, Elysia viridis, has made claims to eat Bryopsis exclusively.
<<Mmm, not "exclusively"...at least not according to seaslugforum.net>>
The problem I am having is finding this slug in stores?
<<I think this animal is more a cool/temperate species than a tropical species, based on its distribution in the Northeast Atlantic>>
I have been told my LFS that the Lettuce Sea Slug is the same thing as the Viridis, however I am not sure if they are.
<<Elysia crispata (Lettuce Sea Slug) is a distinctly different species from E. viridis hailing from different locales...and quite apparent when viewed>>
I know they are of the same family but not the same species?
Can you help me decided on whether or not to buy a Lettuce Sea Slug for my battle, or if not, where I can obtain an Elysia Viridis?
<<I would NOT buy the Lettuce Sea Slug.  Little is known of what these animals really eat (even though they are actively marketed/sold as grazers of "hair algae").  Many of these slugs are able to harbor the living chloroplasts of the algae they consume which continue to photosynthesize within the body of the sea slug, providing it with sugars for its own nutrition.  E. crispata have been found to contain the ingested symbiotic plastids from Halimeda incrassata and Penicillus capitatus...hardly "hair" algae.  My own anecdotal observations and experiences would seem to bear this out as I have never known one survive more than a few weeks to months in a home aquarist's system, even with an abundance of hair algae present, as they all seem to ultimately shrink and die from starvation.  I think a better choice of slug to try would be from the genus Aplysia...the Sea Hares.  These slugs; at least in my opinion/experience, are more hardy and much more likely to consume the filamentous algae than E. crispata>>  
Thank You for Your Time
<<Happy to share.  EricR>>

Bryopsis/Derbesia...any suggestions would be greatly appreciated ) 3/14/07
OK crew, here is the deal.  I have been fighting with Bryopsis and Derbesia in one of my tanks for the last 4 months and it has gotten way out of control.  I would say 100% of my tank is covered.  I have tried anything and everything and I am to the point of taking the tank down - which will come with much dismay.
The tank is a 30 gal with 2 DE 250 14k with a 15 gallon sump.  I know it seems a bit excessive with the light, but it is needed for the 30+ heads of Acro in tank.  I only run the light cycle for 5 hours.  Fish are:
1 small scribbled fox
1 small scopas tang
1 six line
5 tiny damsels
1 Vanuatu Chromis
I use a model ASM mini G - running wet, phos reactor with Phos, mini fuge, calcium reactor, UV.  I have tried sea hares, snails, crabs, manual export - siphoning through UV to kill spores, nutrient reduction, blackouts...you name it.  It just keeps getting worse.  I was contemplating running a 5 gallon bucket off to the side filled with m Acro to try and out-compete the Bryopsis, but I am thinking that the only way that it can be beat is starving it the light which is the last element that it seems to be utilizing - hard to do with  SPS.  Any suggestions?  I know the tank info is brief so if there is anything I missed, let me know and I will try and answer.  Thanks in advance for your help.
Dr. J / Justin
Re: Bryopsis/Derbesia...any suggestions would be greatly appreciated ) 3/14/07
Without lifting a finger or scrubbing a rock, you can watch the nuisance abate significantly (if not wholly) by strictly maintaining a steady pH of 8.6 for three weeks while increasing water flow in the tank and skimming aggressively (making the skimmer yield daily skimmate to the tune of 4 oz min per 75 gall AQ per day)
Applying ozone at the same time (increasing Redox a bit.. a steady 400mv is fine... no need to get too aggressive here) will also favor desirable organisms and functions that will quickly in turn outcompete the nuisance growth.
This recipe (high pH and skimming) has been shown time and time again to work... there may be some posts in the WWM archives by me and from folks that attempted it. I'm sure such testimonials are on RC, RF, MD, etc. I would be surprised if you applied the advice and did not say a month from now that the algae was nearly gone.
The key is actually maintaining that steady and strong pH. Most people are too lazy to do this faithfully and/or they are not using a dual stage Ca reactor and instead just blowing algae fertilizer into their aquarium (excess CO2 mitigated by the already excess CO2 in the well-insulated winter-time homes)
As far as the "keep off the record comment," I ask... WHY? Do you not want to share with others in the same spirit that you take information? I don't see why more people than a two-way exchange should not benefit from the discussion and suggestions/solutions. On the contrary, it seems a shame (read: selfish) to horde the advice and discussions.
Justin... don't be afraid of appearing typical my friend. We are all (beautifully) typical people/hobbyists at least in some ways.
Bob... please do archive my excerpted response if you like.
kind regards to all,
Re: Bryopsis/Derbesia...any suggestions would be greatly appreciated ) 3/14/07
Thanks for the quick response!  I just didn't want it to be a waste of time to record.  If it can help, then by all means post it, please.
I tried the high PH for a few weeks with devastating effects on my SPS.  I was dripping Kalk continuously and maintaining a ph of 8.5.  The only problem was my alk would shoot up to 14 dKH and the SPS would begin to fade in color.  I had my reactor off line for a bit after to try and keep the alk around 9 or 10, but then it would drop down to 6 or 7 during refills.  The tank currently has 3 maxi 1200's for flow on a wavemaker.   I fill the collection cup up full everyday and also clean daily.
I thought about the excess co2 from the reactor and tried taking it offline completely.  This also proved disastrous with an outbreak of dinos - not sure from what exactly, though.  I run the effluent into a fuge that is lit 24/7 ( used to do reverse light cycle.  Is there a good way that I can increase ph without the flux in the parameters?
Re: Bryopsis/Derbesia...any suggestions would be greatly appreciated ) 3/14/07
indeed... the pH is not the problem bro, the rollercoaster in water chemistry was. The average of natural seawater is 8.45 (often higher in places with heavy stony colonies).
Now in aquaria, the high pH can be more dangerous if ammonia or a heavy bioload is present, but those are exceptions and not an issue here with you/experienced aquarists.
For maintaining a high pH and solid ALK without the rollercoaster, you can just do large weekly water changes, supplement with Calcium hydroxide, and forget about all other supplements and spikes.
The NSW brings in a moderate level of Ca and ALK... the carbonate matter in your aquarium carries the ball on the Alk between water changes... the calcium hydroxide replenishes waning Ca levels while indirectly supporting ALK by its caustic nature (neutralizing nitric and carbonic acids that would otherwise burden the Alk of the system)
Its all really that simple my friend. Water changes and Kalk slurries.
Confirm how much calcium hydroxide to use by determining your daily demand for calcium (run three days without Ca supplements... test Ca before and after then divide by three to get a more accurate reading from your hobby test kits
Re: Bryopsis/Derbesia...any suggestions would be greatly appreciated ) 3/14/07
Sorry for more questions: )
 When you say slurry, do you not recommend dripping constant Kalk?
Would you recommend switching synthetic salts - I use CoraLife
Thanks again for your help.  I will put it to use ASAP.  My wife and I are expecting our first child this week so hopefully I can find the time to do this treatment faithfully!
Re: Bryopsis/Derbesia...any suggestions would be greatly appreciated ) 3/14/07
Along with the good advice Anthony suggests, I feel you have waaay too many fish in your 30 gallon tank.  I believe nutrients are being produced faster than
they can be removed.  I run a 40 mini reef and have three fish, False Lemon Peel, Dottyback, and a Goby/Pistol Shrimp combo.  I do not feel comfortable adding
another fish.  Even though they are small, the five damsels alone, being very active fish,  can produce a good deal of waste.  Good luck on curing your
James (Salty Dog)

Bryopsis concern, control   12/17/06
Hello Crew,
I have had a break out of what seems to be Bryopsis, from everything I can read it seems the closest match to what I have. It is grassy, but very fine and grows in clumps that seem to root into my live rock.
It seemed to start growing when I switched out my 10K MH's to the 20K's? The other only thing that I changed was that I started directly feeding my corals with Borneman's recipe about twice a week.
<Maybe more than your tank can handle, cut back.>
I'm sure this contributed to an increase in available foods for algae.
<Sure sounds like it.>
I have a sump with a skimmer and a bunch of grape Caulerpa to help combat the nutrients.
<Chaetomorpha would be better, less potential for problems than the grape Caulerpa, may want to consider switching.>
Also there is a decent patch of Halimeda growing in one corner of my tank, also on the live rock.
<This is fine.>
My parameters are:
dKh- 9
cal- 360
ph- 8.6 constant day and night <A little high.>
phosphates 0.1 according to Red Sea test kit <Here's your problem.>
spg. 0026
An idea I had was to cover portions of my live rock which are covered with this algae with black plastic, thus cutting off the light to the algae.  Would this be a viable means to try and kill off this nuisance algae.
<A band aid, better to address the source of your phosphates.>
I have stopped using the coral food and feeding very lightly to decrease added nutrients...my tank is a 65 gal with four powerheads for circulation and my return from the sump, Deep sand bed, 4 inches deep.
<This, along with water changes will be most helpful.>
<Welcome!  -Mich>

Green Algae 12/14/06
Five months of pouring over C.M.A., New Marine Aquarium, and other research.  One month of spending the majority of any disposable income to purchase equipment.  A few mistakes to send an aquarium on the path to destruction. I feel sheepish coming to the fish deities for help, but please have mercy on my soul, for I’m only a beginner, and I don’t want to ruin what has been a good thing.   I hope I’ve provided necessary information below for corrective action advice.  <All will be forgiven with a little penance.>
The Problem:  Algae break-out.  Green.  Feathery.  Nuisance.  It is covering live rock, sand, and starting to cover the aquarium wall.  Pictures enclosed.  I’m a newby but used to science and research—it appears to possibly be Bryopsis or a related species.  Don’t have a microscope at home to verify.  Pictures of the tank (before invasion and after invasion) enclosed.  Couldn’t get a close-up of the stuff but the *strands* have a similar *general* bipinnate look as Caulerpa taxifolia for instance, except they are much smaller, lighter, and quite feathery and not connected by a horizontal stem.  <Good description>
Tank Contents (Currently 4 weeks old, 29 gallons):
10-15 lbs live sand—enough for .75 inches of substrate.  
30 pounds of live Fiji rock  
High quality synthetic Oceanic Marine salt                      
First 2 weeks: Tap water.  Switched to R.O. at the beginning of algae bloom (3 weeks after setup)  
6 red-legged hermits—added after initial diatom “bloom,” which occurred 1  week after setup and lasted for 1.5 weeks  
Two feather dusters—added just before green algae became a problem
<Sounds good.>
Fluval 205 Canister filter.  Has sponge mechanical prefilters, two slots for carbon packs, and two slots for BioMax biomedia.  First 3 weeks, kept “default” setup.  When algae started to creep up as problem, I removed one BioMax biomedia slot and replaced with Phosban in a media bag, wedged between two layers of filter-floss so the Phosban particles wouldn’t break up and contaminate the tank.  Next step is to remove other biomedia slot.  What should I put in its place?  <I like PolyFilters, remove most contaminates and change color to tell you what it is removing.>  
Maxi-Jet 900 powerhead (230 gph)  
Bak-Pak 2.  Kept biomedia in until my bubble-trap came in the mail yesterday, so it was in for four weeks.  Threw out biomedia and replaced slot with the bubble-trap.  I know keeping excess biomedia adds excess nutrients for unwanted growth of certain organisms. This probably contributed to current problem.  <Likely not a huge problem.>  
150 W Heater  
Lighting.  JBJ DX 2x65W compact florescent lighting, consisting of 1 blue actinic and 1 10000K daylight bulb.  Photoperiod 10 hours a day, on a timer.  Yeah, too much light for not having any photosynthetic invertebrates yet.  Wanted to build reef slowly. <Slow is good.>
Excess light probably contributed to current problem too.  Dumb mistake.  Not sure what to reduce to.  <Would mask problem but not solve it.>  
Additional lighting: 1 blue LED nightlight. Goes on when compact fluorescents go off.  Noticed a colony of my green aquatic enemies growing in a circular pattern exactly where the light enters the tank.
Water parameters:  These have been steady after the first five days, except for phosphate.  After four or five days, phosphate levels were at .5 mg/L.  Started using R.O. water and levels dropped. <Good>  Supplement with Kent’s liquid calcium and dKH every 4-5 days.   Dosed once with 2 mL Kent Strontium and Molybdenum after week 1, haven’t used since due to fear of outbreaks.
<Do not dose without testing levels, frequent water changes take care of most needs anyway.>   
Temp: 78-80 degrees F
Spec Grav: 1.024
pH: 8.0  <Little low.>
nitrate: 0
calcium: 350-360 mg/L
phosphate: .1 mg/L  <That the problem.>
Alk: 12.1 dKH
Ammonia: 0
Nitrite: 0
Familiar with the idea that Low Phosphate/Nitrate levels don’t mean too much with this green algae breakout because they are locked up in the algae.  <Yep, so if you have measurable amounts in the water that means you have lots more.>
Regular Maintenance:   I’m very enthusiastic about the tank and checked water parameters frequently at the beginning.  (Once every couple days.)  <Good>   Weekly maintenance includes disassembling the canister filter and cleaning off the intake assembly, running the sponge prefilters under water, gently rinsing the activated carbon bags, and doing partial replacements of the biomedia.  Last week, I put in the Phosban to replace one biomedia slot.  I used an aquarium scrub-brush for the inner walls of the tank, and have done biweekly cleanings of powerhead rotors.  I cleaned the interior of the skimmer once to remove a few strands of pest green algae and have cleaned the skimmer pump intake.  I clean the glass tank cover and the glass housing the lighting weekly.
<Good, looking to change 10-20% of the water each week.>   
Current action:  
I noticed the green algae took a liking to the heater.  Before I washed it off, it was covered with the stuff, and I have the thermometer next to the outlet of my canister filter, so the flow is decent—must enjoy the warmth.  <Have noticed this in other tanks too, warmth and liking the smooth glass surface is my guess.>
Short-term S.O.S.—S.O.T.? (Save Our Tank)—Solutions:  What do I do with the rock, live sand, and tank walls?  I don’t know what to do.  If I try to scrub the stuff off the sides of the tank, it may break into pieces and bloom in more areas of my tank.  I think it did this already after I tried to break some off the walls last week.  Three days later and a whole new crop of colonies were growing on a nearby clump of live rock.
<Manual removal is big here, you may see a short term increase in algae as it gets a chance to colonize new areas, but you are removing its fuel as you remove biomass, will slow down growth in the near future.>   
Long-term solutions to eliminate and/or prevent the problem:
Reduce temp of tank?  <80 is a good temp for reef tanks, no action needed here.>
Reduce photoperiod?  If so, to what?  <Photoperiod is ok.>  
Introduce some Caulerpa to the tank to compete for resources?  <Would help, although there are better macro choices than Caulerpa.>
Will a Salarias fasciatus be interested in this stuff?  The alga is stated to be filamentous and some sources describe this fish eating the stuff, although they prefer BGA.  I don’t want to starve a fish if this isn’t the case.  
I’ve read certain sea slugs eat the stuff.  True?
<Adding more bioload at this point will only compound your problems.>
Should I remove anything else from the canister filter?  <Could remove everything but the Phosban and PolyFilters if you get some,  everything else is fairly unnecessary.>
Any other ideas?
<Water changes (RO water), manual removal, and time, this is not terribly uncommon for a new tank.  Will be replaced in time with "higher level" algaes (Coralline) with time.>   
I’m sincerely sorry for all the questions.  I’ll be pulling my hair out much sooner than this “hair.”  I just don’t know which solution yields the most success or the order in which they should be attempted.  I appreciate any help you can provide.  I can just see this stuff creeping out of the tank and strangling me in my sleep.  It will happen.
With much respect,
Andy P
<Time, patience, and water changes are the key.  Success will follow.  Good luck with your new tank.>

Hair algae similar  9/28/06
Hi there,
I've had a problem for quite a while now with an offensive growing algae similar to hair.  It's just getting worse and the more I do in water changes and adding natural bio-clarifiers like Marine SAT products, seems wasteful.
<And in the long/er term, not of use>
For about the past 4 months now, 25-30% weekly water changes are done (store bought 0 TDS DI Water),
<Look into getting your own R.O.>
which the fish and corals love and my wallet hates.  I also have plenty of baseball sized urchins and a very healthy Foxface fish and neither will help me in the least with this infestation.
<Perhaps this is a BGA/Cyano... not palatable to most...>
Tank specs:
210 gal Oceanic 7x2x2
Amiracle refugiums for each overflow w sand, snails, Chaeto, razor Caulerpa, and reef lobster
ASM G4 Plus skimmer in main connecting water reservoir.
Mag 18 return pump  (thinking of upgrading this)
2 Tunze stream pumps
2 Internal AquaC remora Pro hang on units (never took them off yet after upgrading ASM)
500 lbs of live Fiji sand
~250 lbs of Marshall island and Tonga rock
Water temp: 78F
SG: 1.024
NO3: 10-15 ppm (water changes weekly)
PO4: barely lowest color in chart (tested by LFS)
<Likely readily taken up...>
All DI water is store purchased, salt and top-off.
All food is dry pellet / flake only, formula 1 & 2,  and never any left over after 60 sec.s (pigs)
5 inch Niger
5 inch RS Sailfin
4 inch Foxface
3 inch Majestic angel
4 inch Chrysurus angel
4 inch Maroon clown (Satan wannabe)
6 blue/green Chromis
few cleaner shrimp
various hermits, Astreas, Nassarius, sand stars
2 baseball sized urchins
2 small tuxedos
1 chiton
6 or 7 decent sized SPS corals
4 crocea clams
few LPS corals  (angels like them too well, lol)
3 x 250w Hamilton 14k lighting with dual fans
I've enclosed a pic of what this stuff looks like and I've heard there is a type of slug that specifically eats this stuff and does a good job.  I would love to know what that is so I can purchase some before I am forced to get out of this hobby.  It's not making much sense to me to shell out $40 a week in water changes alone with no progress in sight.
<Your own RO...>
I just bought a '68 Mustang convertible and I think it could use a couple of extra bills a month :-)
In the last week, I've tried one more idea though.  I bought 2 pounds of grape Caulerpa and put a pound in each overflow in the tank and put a dual mini PC light over the overflow and light it for 17 hours a day.  Since each of my refugiums are only medium sized each and can't hold a boatload of macro, I figured there's at  least another 20 gallons of water in each of my built in overflows, might as well put that space to nutrient export use.  
<Good thought>
With this wild idea, I've noticed I don't have to manicure the hair like stuff but only once a week, and not twice a week which is an improvement already.  I've heard from grape users, that once my grape "kicks in" it should be able to eat the food/whatever the hair is feeding on more rapidly, and the stuff should die away in the future more and more.
Oh and I have a 75 gal tank up running with a grouper and an angel and never had problems like this using the same store bought water...so it's definitely tank specific and not salt/water/additives.
Any clues or suggestions ???
Frustrated, and thanks in advance,
<Mmm, looks more like a Chlorophyte than a Cyanophyte... greener, thicker strands... but w/o microscopic examination, can't be sure... Please read here: http://www.wetwebmedia.com/greenalgcontfaqs.htm
and the linked files above... to grant you an overview of possible techniques, predators, competitors you might consider... Bob Fenner>

Help unknown algae  - 1/30/2006
Hello Crew,
Thanks for the great site!  I have a question regarding 100+ sprouts of an unknown macro algae that growing all over my 3 week old "Fiji Premium Live Rock".  I have 90 lbs of it in my 50 gallon new reef tank.  I guess I want to know if it is a problem, and if it is a problem what should I do to remove?
<Mmm, might be Derbesia: http://www.google.com/search?q=derbesia+identification>
I do not have a sump to place competing favorable Algaes.  I do have a Magnum canister filter and an Aqua-C Remora.  
Thanks in advance for your help.
<Need more info... or to direct you to the articles, FAQs files on WWM re Algae Control... Bob Fenner>

Re: Help unknown algae   1/31/06
Thank you for your response.  What more information do you need (I have included 2 more photos)?  I reviewed your links and they did not seem to help me understand what I am up against.
<Really? A bit wider search will show this genus is hard to control once established... most "algae eaters" find it unpalatable...>
I have a yellow tang, scarlet hermits, Mithrax crab, Astrea, Cerith, and Nassarius snails and none of them will eat it.
Your advice is greatly appreciated.
Tom Hobson
<Umm, go back young man... to WWM. Read re Green Algae, Control... Bob Fenner>

Re: Help unknown algae   1/31/06
I'm sorry but I must be a little too dim...
<Mmm, nope... gauging from below you're at least in the Metal Halide class of intensity>
but I do not see the light.  I have read the algae control section.  I have restricted food for the fish (nutrients).  I have added, "tang heaven red and green" from IPSF.com to compete.  
Ammonia    0
Nitrite    0
Nitrate    5
Ph    8.3
Alk    300+
<Mmm, the last is likely calcium concentration in ppm?>
I have not tried an urchin, or Elysia.  The only other things I think of is to pull the rock out and try to razor blade the plants off or throw it away and start over.
<Not yet...>
  Is there some little tidbit that I am missing that will prevent me from tossing the live rock?
<Yes... I'd try the Kalkwasser trick here once or twice. Mix up a batch and add some till the pH reaches about 8.6... should precipitate soluble phosphate and really shake the Green. We'll "escalate" (Shades of "Nam", and soon the Middle East) what you might do here next if this doesn't do the trick. BobF>
Tom Hobson

Re: Help unknown algae   1/31/06
I guess I need to cut the chase here.  If this rock is going to be a continual problem, I want to throw it out and start over with a new batch of live rock.
<Mmm... not really a good, practical approach. The new rock (or even no rock at all!) can/will develop the same algae/problem from spores left about, and prevailing conditions... Best to take a sort of long haul, steering a large boat with a small rudder attitude here... create competition for nutrient, reduced nutrients period, and allelopathy means of control...>
As costly as this may be, I would rather spend the money than beat my head against a wall.  This tank was supposed to be an enjoyable hobby right now it is pain.
<Believe you me, I understand... as stated, categorically I'd launch a blitzkrieg with the three avenues above. Bob Fenner>
Tom Hobson

Algae control 6/23/03
Dear crew
I need your help with an algae problem.
<napalm and a flamethrower... works every time>
I have a Bryopsis (it's green algae so I think it's Bryopsis) in a six 5 months tank.
<double napalm>
I have a deep sand bed, about 15 kg of live rock (waiting on some more), Sarcophytons, brain corals, clown anemone etc....
I have about 20 medium size  fishes (mostly tangs, 2xmarron clown, 2xyellow tangs etc....) Tank is 150 gallons, and I keep removing by hand quite a few grams of Bryopsis every week. Levels at everything are normal, and water changes are about 10% every week.
Is Bryopsis going through a cycle or it's being fed by some factor which I haven't checked ? Waiting for your reply Kostas (Greek reef)
<Bryopsis is actually not so dependent on "poor" water quality (nutrient/low flow, etc) as many other pests. It can be tempered, however, by maintaining a more consistent pH (very steady day and night 8.6) and a high Redox (400-450mv). You may also try some of the Rabbitfishes (AKA "Foxface"). We also have almost 50 pages of coverage on plants and algae in our new marine aquarium book:
Best regards, Anthony>

What tang will eat Bryopsis?
Will any tangs of the genus Zebrasoma eat Bryopsis? << Doubtful.  But possible. >> My tank now looks like a rain forest, where you literally cannot see through the tank ( I was on vacation for a few days). << That is how I like my tank to look.... but the wife sees otherwise. >> I don't want to boil the rock I paid $700 for, and I've wanted a tang anyways. << Don't boil it!  That is bad.  I would rather see you add a bunch of hermits/snails and manually remove the algae.  Or, just learn to love it and live with it. >> I'm looking at either a Z. xanthurum or Z. desjardinii preferably. Any thoughts? << Between the two, I would think the Z. desjardinii would be a better choice, but still not likely.  You could try a rabbit fish, or a Combtooth tang like a Chevron. >>
<<  Blundell  >>

Bryopsis control 20 Aug 2004
I'm having a major problem with Bryopsis. <Sorry to hear that Brandon.> I was able to keep it somewhat under control, but I had to go on a sudden business trip for 2 weeks. I get home, and my tank looks like the top of a rain forest canopy. <YOUCH> I pulled out what I could, but it is even on the sand. <Turkey baster works wonders for that.>  It is so thick on the glass that my Magnavore can only make one pass and it is jammed with algae. <Major problem there.> I have put 3 crispata Nudi's in the tank, along with several snails and hermits, but they aren't making a dent. The only advice I've gotten is to boil the $600 worth of live rock to kill the Bryopsis. <Well I can tell you that I've been known to pull all of it out, put it in buckets, scrub the Bryopsis off.> That doesn't seem rational, and besides, if it is on the sand, what would keep it from coming back? The tank is about 2 months old. I only have one fish, a Pacific Redstripe Hogfish. I have a massive Precision Marine Bullet skimmer, and all parameters are now normal after cycling the liverock. What is my best solution at this point? Do I leave the lights off for a period of time? <Cut back in your lighting some, raise your calcium levels. Cut WAY WAY back on the feeding of the fish. Something is feeding the Bryopsis and you have to figure out what it is. And you have to get what's in there out.  Take a look at this http://www.wetwebmedia.com/avoidingalgaeproblesm.htm for basic ways to take care of the tank and avoid algae.  Now for your more immediate problem.  I really advise the bucket method then you don't put tons of spores back into your tank.  Do you have a way to run carbon in your tank? Good luck and lets follow up on this, MacL>Thanks!

One man's account of a titanic struggle... with Bryopsis
Bob, I just wanted to let you know about a new log I have started keeping to chronicle my battle with Bryopsis and hair algae.
Please include a link to the page if you feel it adds value to the readers of WetWebMedia.com
Mark Linton
<Thanks. Will post. Bob Fenner>

Re: brittle star question, beh., and alg./Bryopsis control...
Thank you.
I will try to get a video to verify
<I look forward to seeing it.>
and I also have another question concerning one of my other tanks
it has a bunch of this green algae Im am pretty sure that it is Bryopsis because it looks like small palm trees and it is taking over some of my corals and my rock is covered and I can't seen to get rid of it. Is there any suggestions?
Nitrates 0 nitrites 0 phosphate 0 PH 8.0
<Yes, I think you will find these articles helpful. Please read here:
Hope this is helpful.
Mich><<Try some small species of Cowries... C. moneta, C. caputserpentis... RMF>>

Marine Algae/Feathery I.D.
I have a question about alga in one spot of my tank. I looked on the FFE site and wet web media of course, and haven't what I was looking for. My reef tank is great , I was wondering what kind of alga looks feathery. Un fortunately I am colorblind but I think it is green I think) It is growing next to the Caulerpa I have in my tank. This stuff looks like a bunch of little feathers.
<Derbesia as a genus is very common in captive reef systems... and feathery in appearance>
I have a purple tang and haven't seen him pick at it, but I feed him regularly so he probably isn't really looking for anything else. My tank is totally encrusted with coralline and looks great. Is this just a nuisance algae? Should I take out the little bit that is in there or leave it?
<Nuisance... yes, as in not very palatable to common algae eaters...>
ps I just finished your book for the second time and am adding it to my collection. thanks and take care
<Ah, glad you're enjoying it. Do consider depriving these nuisance forms of nutrient... and growing desirable macro-algae that will produce chemicals to further limit its growth. Please read the "Algal Filtration" and FAQs sections on the www.WetWebMedia.com site for the particulars. Bob Fenner>

Bryopsis? Algae problems?
Maybe you can help.
<I will try>
I've developed a problem with a dark green macro algae that has a featherlike shape, very fine feathery growth, but definitely not a type of Caulerpa or hair algae. The algae grows in clumps with the feathers branching out from a central location.
<There are a few species of common pest Greens that fit this description>
Another reef hobbyist identifies this algae as Bryopsis. I'm not sure if that is the correct spelling.
<Bryopsis... likely so>
So far I have found nothing that will eat it. I have had Desjardini tangs, purple tangs, red, blue, and scarlet hermits, emerald crabs, sally lightfoot crabs, Astrea and turbo snails. Nothing wants to touch the stuff.
<Also a common complaint>
Perhaps you can make some recommendations.
The aquarium is a 345 gallon reef with 3 - 400 watt halides, 4 - 160 watt VHOs, downdraft skimming, calcium reactor, Berlin method. There are no other algae or nutrient problems, in fact so far the biggest problem has been the corals growing too fast. I'm having to prune my Acropora almost every 3 months!
75deg F
calcium 475ppm
ammonia, nitrite, nitrate 0
phosphate 0
ph 8.0 night 8.3 day
ORP 435 (no ozone used)
adding Kent marine
strontium, Lugol's iodine, coral Vite, Dt's phytoplankton, Microvert
trace elements are used infrequently and in lower dosages than recommended
Please help
Thanks, Doug
<I recommend the growing of Caulerpa, Halimeda in a separate lighted sump here... these "other" Chlorophytes can/will produce chemicals and use of nutrients that will limit the pest algae proliferation... Other possible algae eaters I'd recruit are posted on the www.WetWebMedia.com site... in particular, look into Cypraeids available more and more... for the purpose, like C. annulus... as you might guess, there definitely are animals who do eat this stuff... otherwise the wild would be overrun with it.
Bob Fenner

Eliminating Nuisance Algae
<Scott F. with you today!>
I continued to be troubled with Derbesia, which has overwhelmed all Caulerpa in my refugium.  I can scrub the rock, but it just regrows. I would not mind if I could keep it confined to the refugium. As an experiment, I soaked one of the Derbesia-covered rocks in my 110 gal fish tank in RO water for 10 minutes, and then replaced it in my tank. This appears to have completely paralyzed the Derbesia (and hopefully eliminated its "roots" within the recesses of the rock).  The coralline algae appears intact (@ 24 hours).  I continue to have adequate biologic filtration in my trickle filter and 55 gallon refugium.
<Hmm...interesting protocol...>
My question is this...if I were to remove all rocks from the fish tank (~50 lbs), scrub the Derbesia of them, and then soak them for 10 minutes in RO water, before replacing them in the tank...would you expect the fallout from death of organisms within the rock to be sufficient to disrupt the tank?
<Quite possibly, the die off could be extensive among the micro and macrofauna in and on the rock.>
Or would the remaining live rock, algae and trickle filter along
with the protein skimmer manage the load? I am hopeful that I may have found a means to eradicate Derbesia without toxic chemicals or heat sterilization.
Thanks, Sam
<I suppose that this may be a possible "fix" for the problem, but I think it be better to look at the root cause of the nuisance algae breakout and eliminate it (not to mention the potential "collateral damage" caused by the fresh water dip. In fact, the die off of plants and animals could load up the system once again with nutrients that can lead to...algae.) Otherwise, if conditions (chemically and otherwise) remain the same in the tank, you'll experience the same problem again and again, IMO. Eliminating nuisance algae is all about nutrient export! Start by reviewing the basics: Make sure that the protein skimmer is working well- pulling out several cups of dark, stinky product a week. It's definitely your first line of defense. Also, revisit your husbandry techniques: Employ frequent (like twice weekly) small (approx 5% of tank volume) water changes. This will help prevent nutrients from accumulating. Be sure to use quality chemical filtration, such as activated carbon and Poly Filter pads, and change them  frequently. Be sure to clean and/or replace any mechanical filtration media (i.e; pads, filter "socks", etc) regularly, as they can accumulate detritus and contribute to the organic/nutrient load in your system. I'm not a big fan of Caulerpa, but if you're using it in your system, harvest some on a regular basis (very carefully, trying not to tear any of the fronds in the process, as they may leach noxious substances into the water). This will essentially remove nutrients from the system permanently. Finally, if you are utilizing plastic media in your trickle filter, consider removing them, and letting your live rock and sand (a 4-5 inch bed of sand can do the trick) do the biological filtration and denitrification for you. All of these are basic things; you may have thought of them before...But reconsider and re-evaluate their use, and what benefits they can provide. It might just make a difference! Good luck! Regards, Scott F>

Green Algae Question
Regarding the Bryopsis in particular, I have read on a few other pages that Lettuce Nudibranch (Tridachia crispata) has successfully taken care of this nuisance algae. I also understand that they are rather hard to keep, mostly due to starvation from what I have read. I was looking for any input on this particular species to see if this would be a natural or at least decent predator for this algae.
<Yes, will eat algae, but far better to eliminate the source of the algae (nutrients).>
Currently this is all occurring in a 135 gallon tank with a Berlin Turbo acting as the skimmer with no real noticeable effect on deterring the algae growth.
<Do you have to empty the cup every other day?>
In fact, I just see the damn stuff popping up here, there.. soon to be everywhere.
All in all, would this lovely little sea slug be a helpful ally in my upcoming battle, or will he/she just become even more of a pest to the overall scheme of things? -Andy
<Could help, but I am more of the mind of discovering and correcting the root cause. -Steven Pro>

Green Algae Question II
I too am interested in the root of the problem.. I tested everything again today and received the following results.
PH 8.2
Ammonia 0
Nitrite 0
Nitrate 0
Temp 78
Alk lists in "normal" range of test kit
Calcium about 400
O2 also reads "normal"
Phosphate 0
- I wish I could be more specific about the "normal" readings but
unfortunately, I am unable to determine what the exact reading is other than "normal".
<All of the above seems good.>
As for the Berlin skimmer, I emptied out a bunch of lovely smelling green gunk from it today, but I haven't seen much of a need to empty it every few days at this point. It currently is running full bore, and it seems to be working like it should, but not to the point where it needs to be emptied frequently.
<I would play around with the skimmer some more to attempt to increase production; allow more air into skimmer, clean pump to increase flow, etc.>
I am currently trying to battle a small BGA outbreak as well with this
Bryopsis algae, but it looks like the BGA is starting to settle out.
Are there any more tests that I can run on this that you would recommend, or anything in particular that I can look for to try to pinpoint this issue?
<How old are your lamps, how often do you perform water changes, what salt mix do you use, what is your source water, do you feed too much, etc.?>
Further background on the tank - 135 gal, 4 60" VHO - 1 super daylight, 2 50/50, 1 actinic
pumps: Mag drive 950 in sump, 4 AquaClear 402 in tank.
fish: 2 clarkii clowns, 1 Sailfin tang, 1 flame angel, 1 black ray shrimp goby, 1 fire goby.
Inverts: 3 sand sifting stars, 1 rather large green carpet anemone, a few purple mushroom corals on a rock, 2 cleaner shrimp, 1 peppermint shrimp, about a dozen or so hermits (mostly blue legged, 1 scarlet and 1 other (he is getting big though). 150 or so pounds of live rock.
<Take a look at the articles and FAQ's on algae control for some other ideas. There is a reason. Algae requires nutrients to grow. You just have to find out where they are coming from and correct it. -Steven Pro>

Green algae question: Bryopsis
Attached is a picture of some green algae that is starting to grow in my aquarium. It seems to be doing rather well as there are a few patches starting to grow. This, by far, is the largest of the patches. I am trying to figure out a few things about it.
1: what is it
<Bryopsis sp>
2: is it a "pest" algae
<severely a nuisance>
3: should I remove it / harvest it
<good luck... bores into calcareous substrates and is difficult to extract completely... better to starve it out with aggressive protein skimming and high pH (8.6) and alkalinity (12dKH+)>
Lastly, there is also a kelp like algae in the same picture just to the left of the big green blob. I am trying to figure out what kind that is as well, but I am not too worried at this moment because it does not seem to be reproducing rapidly.
< a Sargassum sp... do enjoy it, not a nuisance although you will need to control its growth eventually by trimming>
<best regards, Anthony>

Ctenochaetus strigosus/Derbesia/Bryopsis
Hi Bob,
<Steven Pro this morning.>
I'll keep this as short as possible. I know you're overwhelmed with mail.
<Between the three of us, it is not too bad.>
I've been reefing for over 12 years and have never had an algae problem until now. I believe it's due to my skimmer taking a crap and trouble for over a month trying to get the new skimmer I bought to work properly (presently waiting for a new, redesigned impeller to be sent by the company). Incidentally, the new skimmer was not cheap. It's a Red Sea Berlin Turbo geared for 250 gallons. Worked like a dream for about 2 weeks then wouldn't perform. When I contacted Red Sea, they informed me the original impeller was flawed and they now have a "redesigned" impeller. In Red Sea's defense, I did receive a prompt response from the company. I don't, however, understand why they put the unit on the market or didn't pull it off or recall it as soon as they realized it was flawed. I'm sure I'm not the only Reefkeeper who ended up with one of the flawed skimmers. At any rate, I've been without sufficient skimming for 4 to 6 weeks now, and low and behold, the Derbesia/Bryopsis have made their appearance in force. Yes, I am attempting to cut back on nutrient addition, but I have 3 large Tangs (Blonde Naso, Yellow, and Hippo (Paracanthurus hepatus)) in this 180-gallon system who prefer to be fat and happy. I've been considering adding a Yellow Eye (Ctenochaetus strigosus) to this system to assist in algae control. First, will he eat these types of algae,
<He will eat some of this algae.>
and second, will the Zebrasoma flavissimus. pulverize him if I do add him? 
Any other suggestions in ridding myself of this plague would be greatly appreciated. I don't like or use crabs--the majority end up killing and eating snails. What's your opinion on the Emerald crabs? 
<Ok for eating some bubble algae, but I do not completely trust them.>
Any good for this problem?
<Maybe helping somewhat, but your better option is to get your skimmer working again and go back to your regular maintenance routine. Without the extra nutrients, the nuisance algae will disappear in time.>
What snails are the best in your opinion?
<I prefer Turbans to Astreas, but a mix is always good. Trochus, Nerites, and Cerith snails are all good and I like Limpets, too.>
I've always had Astreas, Turbos, etc., but they don't appear to be putting a dent in this problem. None of my existing Tangs are the least bit interested in this algae. Any suggestions (other than getting my much-needed skimmer back in action) will be greatly appreciated.
<No, get your skimmer working and maybe in the mean time, step up your water change regimen.>
This wasn't so short after all, was it?:) Thanks
<You are welcome. -Steven Pro>

- Dealing with Problem Algae -
To the Wet Web Media crew:
My name is Lucas and this is the first time that I have written to you. Before I present my problem, perhaps some background information on the tank itself would be appropriate.
The tank is a fifty five gallon with standard dimensions (20x13x48). Lighting is provided by a JBJ 2004 model Formosa light fixture with 4x65 watt bulbs (2 10,000k, 1 actinic blue and 1 6500k). Lights are on for about 10-11 hours per day. I do not have any sophisticated dawn/dusk or nighttime cycles but would like to look into them should I clear up these basic problems first. Filtration is provided by a Bak Pak 2 skimmer (I am thinking of upgrading to a Remora from Aqua C) which is equipped with the bubble catcher to prevent any micro bubbles from entering the tank. Instead of the blue bio-bale, I hang a mesh bag filled with foam and Phosphate/Silicate magnet from Marc Weiss (this is the ONLY Weiss product that I use, for I have not been too impressed with the performance of their products, although I might try their Moonshine moonlight in the future). I make sure that the mechanical media is cleaned weekly at the least and the phosphate media is replaced regularly. Circulation is provided by two Marineland Penguin 660 powerheads placed in the back corners and aimed to the center front with their output breaking the surface of the water and one AquaClear 300 power filter. There is no media in the AquaClear, I just use it for circulation. The tank is located near a window, but there are no noticeable drafts that affect the tank (the window is well sealed and remains closed) and I blocked out any light that may enter through the window and shine upon the tank. Substrate consists of 1inch of Florida Crushed Coral topped by another inch of Nature's Ocean Aragonite live sand. There is no plenum; substrate lies directly on the bottom of the tank. There is enough live rock to fill about one-fourth to one-third of the tank volume, and I make sure that adequate water movement is present around and through the rock. I am trying to replicate a sort of Caribbean biotype within my tank, and the inhabitants as such try to reflect this niche. Organisms are: Two green Chromis, one mimic tang, blue leg hermits and Astrea snails, one Diadema Urchin, one cleaner shrimp, three ball sponges, one finger sponge, Caulerpa algae, one fire coral, button polyps, feather duster worms (solitary and colonial), and various copepods and amphipods.
Now, finally, to my question/problem: the tank is in the midst of a severe Bryopsis algae bloom that has persisted for some time now. The tank itself has been set up for about ten months now and went through the other algae stages (diatom and Cyanobacteria) before this infestation arose. Also, Aiptasia anemones are multiplying like crazy, and I am at a loss to try and stop them. Am I doing anything wrong? Water changes are performed weekly at about five gallons per change using Instant Ocean salt, and the specific gravity is kept at 1.025. The only additives that I use (besides the weekly water changes) are DT's phytoplankton, which is dosed according to the recommended dosage on the bottle, and "balance blocks" from HBH Enterprises. I put a block in with filter medium and phosphate magnet and let it dissolve as needed. Bak Pak puts out lots of gunk daily, and I take very good care of the tank (in regards to the daily maintenance and monitoring). Please help, as I am not sure how much longer I can stand to see my tank suffer like this. <I don't know if I would characterize this problem as 'suffering' - almost all tanks go through similar issues, it is part of a system of natural progression. Two things come to mind that you can do to deal with this algae - first, increase flow within the tank; add more powerheads, randomize the flow. Next, start removing this algae by hand, perhaps with a toothbrush... but never the less, manual removal is the best way to get the upper hand. Also, give this article a read, should provide some background:
http://www.wetwebmedia.com/algaeasfriend.htm > Any help and/or suggestions would be deeply appreciated.
<Cheers, J -- >

- Dealing with Problem Algae, Follow-up -
To Wet Web Media crew:
Lucas again. Forgot to mention that only RO water is used for water changes and evaporation top-off, nothing less. <Sounds good. Cheers, J -- >

Macro hair algae
I have an algae that has grown in my tank that I would like to reduce or get rid of. It is not the typical problem hair algae that most have problems with (I have had that kind myself!). This algae is not long, fine (read flowing or wispy) and the color of "grass stains" or neon green. 
The algae I have is short (1/8 to 1/4 long), coarse, stiff, and is a very dark green in color (almost a black). It grows slowly and is not easily removed from rock where it mostly grows. It does not grow in sand or on glass or just free in the water. (It has a very stubborn root.) I really believe it to be a macro algae. I have been told it comes from Fiji rock.
This algae is found on the light exposed side of rocks.
My water quality is good. By this I mean the corals are extended, the fish are active and eating, etc. My PO4 is measuring .1. I use VHO and MH in this 180 gal reef tank. I use a Tunze skimmer and a Ca reactor. I do not add anything else. I am also using charcoal in the sump most of the time. Water changes of about 20% per month. Temp in the lower 70's and stable. Tank and sump have live sand. 
I have good water flow with 2 returns plus 4 Maxi Jets on 30 sec cycle for water movement. I feed 2 cubes of frozen store bought fish food a day. Water comes through a Kold Steril unit.
I have tried Rabbit fish, dragon or bullet gobies, Yellow, Kole and now a Naso tang to remove it. I have some snails and a few crabs but not the recommended amounts. I had more they have slowly died off. They do not appear to have any effect on it. 
I do not know what to try next. Can you help? I am at my wits end and my wallet can not stand many more failures.
Thanks in advance!
< What you describe is very likely an algae of the genus Bryopsis (or Chlorodesmis) if it is jointed/branched or Derbesia (if long, unjointed)... and these can be a real pain (as if I have to mention this to you!) to get rid of... and can grow to cover most everything in a reef system... I'm kind of surprised at your having a problem with this algae... as it generally thrives in high nutrient (you don't have much measuring... nor have a "bad" additive habit... using only a Ca reactor...).. But you do have the high light requirement... Usually I'd recommend some of the animals you've already tried... and will urge you to stock one or more members of the Sailfin Tangs... Maybe a Purple, Yellow, Scopas... Zebrasoma. And my fave next animal to try (or at the same time), a couple specimens of Mithrax/Emerald Crabs... 
And this isn't the end of my "bag of tricks" for launching an all-out attack on your algae problem: Do consider putting a Caulerpa species, some live rock for it to adhere to, and an intense compact fluorescent light on a sump/refugium attached to the system... The Caulerpa will not only out-compete these other noisome algae, but produce chemicals that will eradicate it in time (weeks to months)... this is a very safe, effective route to go... as you don't want to kill these other algae and have their decomposition products poison your system.... 
Lastly, (for this pass at your problem), I'd actually (carefully) utilize Kalkwasser (in addn. to your reactor) to raise the pH of your water to 8.4 or so... to precipitate out more/all of the soluble phosphates... there's actually more in your system than meeting your eye/measurer... as it is being absorbed by the algae as it becomes available... sort of like the story of reefs being "nutrient poor"... they're not... instead, they are "nutrient concentrated"... the water around them appears poor because the life there aggressively takes up what's available.... Be chatting, Bob "the algae fighter" Fenner >

Question: I know there's a good number of people who suffer from Bryopsis (wiry, dark green hair algae) plagues, including myself. I've heard they usually crash over time, but I've yet to see it happen in real life. Any cures (biological or otherwise) you can suggest would be greatly appreciated. I'd soon pull out my own hair then my Bryopsis again!

Bob's Answer: Leonard, I still am pumping for the Tang genus Ctenochaetus to munch this algal genus control-wise. Look into the couple of species generally offered for sale out of Hawai'i: C. strigosus (the Kole or Yellow-eye) or C. hawaiiensis (the Chevy)...

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Marine Aquarium Algae Control

by Robert (Bob) Fenner

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