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FAQs Re (some) Algae As Your Friend

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

Related FAQs: Coralline Algae: Use in Marine Aquariums, Marine Algae ID 1, Marine Algae ID 2, Marine Algae Control FAQs II, Marine Algaecide Use, Nutrient Limitation, Marine Algae Eaters, Culturing Macro-Algae; Controlling: BGA/Cyano, Red/Encrusting Algae, Green Algae, Brown/Diatom Algae

But not BGAs

New Print and eBook on Amazon

Marine Aquarium Algae Control

by Robert (Bob) Fenner

Update on Algae and Coral (allelopathy)    10/18/11
Hi Bob and Crew,
I've been following the daily faqs pretty much daily for some time now and always appreciate the great updates and the contributions from all the crew.
I came across this article today regarding updated research in Fiji about the chemical warfare between various forms of algae and sps corals and thought I'd pass it on.
<Thank you>
I found the similarity between the processes described in the article occurring in our reefs and what happens when we have a cyanobacteria or algae situation in our tanks very informative. I also enjoyed the description of the Rabbitfish "quivering" in anticipation of eating the noxious algae.
<'It's certainly a novel finding,' says John Bruno, a marine ecologist at the University of North Carolina, "
Nah... not novel at all. Have written and read re this phenomenon for decades>
Thanks again for being that great resource for all of us.
<Thank you, Bob Fenner>

Hard green algae? No reading...  10/15/08 Hello, <Hi there> Need a bit more guidance. I recently moved my livestock to a 55gl tank with sump, protein skimmer and all the bells and whistles. However, I am beginning to be haunted by what my big problem was in my 29gl tank. That green algae on the sides of the tank that take a razor to scrap off. <Mmmm> Would you please enlighten me on what that is? <... can't from here... Likely a mix of Greens/Chlorophytes, with some BGA, Diatoms...> Probably more important, how do I get rid of it and how do I prevent it's return? Thanks for your help. Mike <... read, here: http://wetwebmedia.com/maralgae.htm and the linked files above. Search before writing us... Bob Fenner>

One quick question. Cnid. interaction, incomp. reactions with/for algae    9/6/08 Quick question.. can the mixing of hard and soft corals and anemone's (she has a lot and they are all touching) chemical reactions be a factor in algae problems? <Quicker answer: Yes... Please read here: http://wetwebmedia.com/cnidcompppt.htm A "pitch" I'm giving today at MACNA here in Atlanta. Bob Fenner>

Algae ID ... Are They Dangerous... Can Be Problematic... 12/06/2007 Dear WetWebMedia -- <Dave and Laura> Thank you for all your help! <Welcome!> We love your website. <Great to hear!> Unfortunately, we lost our pulsing xenia recently to unknown causes. It came with our live rock and seemed to be thriving until suddenly crashing. <Not uncommon I'm afraid... Xenia can be fickle... For some it's a weed and for others it's impossible to keep alive.> Now it's gone, faded back into the rocks... ): Nothing else looks bad, but we're concerned about some recent new algae. <OK.> Stats: 55 gal tank, good flow, <Vague.> 4x65W 10k & actinic bulbs, FOWLR 5 fish (3x dartfish, <Many species of dartfish, and some of the more common ones will fight to the death with conspecifics, for instance only one Firefish (Nemateleotris magnifica) should be kept in a tank of this size as more than one will usually fight till there is only one left.> 1x diamond sand goby, 1x fairy wrasse) 1. Attachment: fernlinkealgae.jpg neardiscosoma.jpg We recently discovered this fern-like algae (we assume it's an algae) growing in a number of places. It looks kinda cool and doesn't seem to be interfering with anything. First question is: What is it? <It is an alga and looks like Caulerpa taxifolia to me.> It looks like the pictures in the books of Caulerpa, but we can't tell from the books if its dangerous or not. <I would remove this from the main displace can quickly and easily become invasive.> One reason we're concerned is that it is near our Discosoma. Second question is: Could it hurt the Discosoma? <Yes it could.> (The Discosoma also appeared on our live rock and even moved from another less stable position to this one, so we're rather fond of it and wouldn't want to see it hurt.) If we need to get rid of it, how do we get rid of it? <I would remove by hand. Will be a tedious process... just keep picking. And please dispose of it responsibly so that it is not accidentally introduced to the local waters.> We don't want to take the rock out of the tank since the dartfish have nested underneath it. <In the log run it may be easier to remove the rock.> 2. Attachment: poriteINtrouble.jpg The other coral that appeared on our live rock is this Porites, but we're concerned that it is in a fight with nearby algae. <It is.> The Porites reappeared on what looked to be dead rock and regrew. It seems to be getting enough light and enough flow but the algae got a foothold on some not-yet-coral-encrusted parts. We're concerned that the algae (ok but not cool) is fighting the coral (really cool). <Yes.> Obviously, we want to help the coral if we need to. <Again manual removal will help, as will decreasing the nutrients in your water and employing a beneficial macroalgae such as Chaetomorpha in your refugium or sump. More here: http://www.wetwebmedia.com/nutrientcontrol.htm http://www.wetwebmedia.com/algaeconMar.htm http://www.wetwebmedia.com/avoidingalgaeproblesm.htm http://www.wetwebmedia.com/scottsh2ochgart.htm > 3. Attachment: brownalgae.jpg We've seen some of this stuff appearing and we can't agree on what it is or if it's good or not. Any help? <Looks like Lobophora variegata to me.> (If we need to get rid of it, how do we do that?) <Again manual extraction and nutrient control.> Thanks again for all your help <Welcome!> Love your site <Nice to hear!>
Dave and Laura

Promoting Algae Growth - 10/01/07 To whom it concerns, Hi, <Hello Parker, Brenda tonight> I have recently gotten back into my hobby of saltwater. <Welcome back!!!> I have a smaller tank (12gal) that is an eclipse with bio-wheel. I have about 20lbs of life rock, a power head for additional water flow, a captive breed clown, a couple hermit crabs, 4 turbo snails, and 2 Nassarius snails. <Nassarius are my favorite snails!> There are good purple and green algae growing on the life rock. The water conditions are good and the tank has been running now for about 2 months. <Great!> I am writing so see what I can do to promote micro and macro algae in the system. <Maybe this article will help you out. http://www.wetwebmedia.com/algaeconMar.htm Brenda> Parker

Algae Succession - 05/20/05 Hello everyone! How are we doing? <Hello!  Doing fine thanks.> I have a new question... <Shoot> I woke up this morning and noticed there is a rusty color growth on some of the substrate and a lot of the rock on one side of the tank.  The tank is about 10 feet from a small window.  No direct light ever hits it.  It's like a reddish-orange color, I'm guessing it is some sort of algae. My tank has been running for 7 days now. <Likely what you are seeing is diatoms or Cyano-bacteria.  Your tank is cycling and starting/going through the succession of algae (diatoms/Cyano/filamentous) associated with such.> Just live rock and substrate.  My ammonia and nitrite are both 0 and my nitrate is between 12-25 right now.  Is this common?  And is this growth harmful? <Common yes...harmful no.  Is what happens.> If so what should I do?  Also when can I add some snails or shrimp? <Leave the tank be and let the cycle run its course (averages 4-8 weeks...usually).  Continue to monitor ammonia/nitrite/nitrate.  Once all reaches zero, do a 50% water change and watch things for another week.  If all remains stable you can add a few snails/shrimp and again monitor for stability.  Regards, Eric R.>

Vacation, auto top off Hi Crew, <Aaron> Wanted to thank you guys for your reassurance on some trouble I was having with my colt. I did indeed just leave it, but did remove the necrotic tissue. The sponge was removed, back to a QT, that I will now be forever leery of, and everything is popping back to normal, albeit slowly. Again thanks for the info, I think it was early enough. <Thank you for this update> I will be leaving for the east for about a week this Spring, Baltimore, will visit and take lots of pictures of The Aquarium at the Inner Harbor. I've tried to design my system to be as fool proof (me being the fool most often) as possible. I do keep Anthias, and I have them on Prime Reef and Formula One and Two flakes, mixed. I added a bunch of slots to a pond feeder I have and it starts to distribute food at about 9am and drops little bits in till about 6pm- seems to work ok for 8 days. All the fish eat this, but I usually supplement in the morning and evening with higher quality foods. I figure a week won't kill anybody in this department, although I do feed filter feeders as well every two days. I will be able to have someone come by about every other day, I'm leaving enough food for 3 feedings, that's 6 cubes. I've added six cubes all at once to see what would happen. <Good experiment> Algae's what happens - sooo I'm ok there I think (any suggestions very much appreciated, as I seem to have painted myself into a corner with a tank that no one I know can take care of). Display is 180 gallons, sump is 30, holding about 20, refugium is 45 gallons.  With the light intensity and time of year I'm burning about 3.5 gallons of evaporative water daily, that would mean I'd need a reserve tank of at least 26 gallons, should probably make it closer to thirty. And this is the real questions, sorry for the rant, should I just bite the bullet on this and buy two DC solenoids, run them in series and plumb the sump to the RO unit using the LifeReef floats? <Could> I'm a biomedical engineer, and I tend to err on the side of caution with medical equipment, seems reasonable to do so with marine systems as well since it's technically life support.  <Agreed... am far more a fan here of a restricted source/volume... like car boys... of about thirty gallon total... simple float valving> Anywho, I've neglected to do this because, well, in the hospital, if a dosing pump fails, there's several people available at all times to fix it. It would be REALLY unfortunate to come home and find the house is totally and completely flooded with brackish water, and I'm unaware of any coral that would do very well with a constant influx of sterile water. Sooo the reserve or the plumb, that is the question! <Agreed...> Really appreciate any input.  PS: What came first the Zooxanthellae or the Coral? <The algae> An often argued subject between my wife and myself, she says the algae because they are the primary producers... <One logical approach... also, in terms of "fossil evidence", PCR manipulation history... the thallophytes are much simpler, pre-date the cnidaria... Look to the popular works of Lynn Margulis here... you will enjoy the speculations as to origins of mitochondria, other endoplasmic inclusions> I say the coral because there are zooxanthellae species in both false and true corals, don't know which of these came first either- so what came first- time- wise? <The Monerans...> Thanks, Aaron and Michelle <Bob Fenner> 

What to do about the algae? Hi, I have been visiting your site for a while now, but this is the first time I have actually asked a question, so here it goes. I have a 29 gallon saltwater tank that has been set up for about a month now. This is what I have in the tank now: 20 lb. of Live Sand 2 small pieces of live rock (about 4 lb. total, hopefully more soon) Other decorations in the tank that are just algae magnets. (just to give hiding spots) 1 Blue Damsel that I used to cycle the tank, it is about 1.5" long 1 Maroon Clownfish about 1.5" long 1 Spotted Hawkfish (That's what it was called at my LFS not sure if its a Dwarf Hawkfish or what) but it is about 2.5" long 1 Emerald Crab (Was told it eats algae, is this true?) 2 Blue-Legged Hermits 4 Turbo Snails Two days ago I purchased a Brittle Star (once again the LFS's tag but not a Green Brittle, I know that much. I believe it is maybe a Spiny Brittle Star based on your pictures on the site) I purchased it in hopes that it would move around the top layer of sand enough to clean a brown colored algae that has begun to grow in my tank. When it sticks to rocks it looks like maybe hair algae, I'm not sure. The Turbo Snails want nothing to do with the bottom of the tank and stay on the glass 24/7, and the hermit crabs and emerald crab stick mainly to the LR. So far the Brittle Star has stayed in a corner between the wall of the tank and one of my decorations, even at night when I checked on it.  It is still alive because if I shine a flashlight near it, it tries to find a darker spot. My first question is this, Is it normal for the Brittle Star to stay hiding for an extended period of time? <Yes... stay out of the light almost continuously> If not, how long is too long? My second question is, Will it get too big for my 29 gallon setup? <Not able to say w/o knowing the actual species> I have a home for it if it will grow too big, or if it is too big right now. At my LFS he said it was about full grown (Its about 5" in diameter). Next, Should I stir the sand if the algae gets out of control? <For what purpose? I would vacuum much of this out/about when doing water changes> I have the lights on for an average of 8 hours a day (I don't have a timer for them yet), I thought this might help. I have read that maybe Nassarius snail would help with stirring the sand. How many would be beneficial for my tank?  <A handful... but... there are other, IMO better ways to curtail the algae growth> I have read one snail per gallon and I have seen that some of you at WWM.com don't care for too many of them. <I am one of these> What about a Sea Cucumber?  <Nah> I have read that they do a good job of stirring the sand. Would one get too big for my tank? <They're just not "worth it" in such a size system IMO> I was thinking of maybe the Yellow Cucumber (from saltwaterfish.com) since it is fairly small to begin with. <One of the best> I have read that they emit a toxin when frightened, would the Hawkfish or damsel (who is a bit aggressive) bother it? I think that's all I needed to know for know, Thanks, Dan. <Dan, do keep studying a bit more... read through the Algae, their control sections here: http://www.wetwebmedia.com/marine/maintenance/index.htm You are on the very edge of understanding better options my friend. Bob Fenner>

Nurturing Live Rock (3/9/05) Hello,  <Hello. Steve Allen with you tonight.> Super Quick question. How can I get those yellows, reds, greens and orange colors on the live rock I have in my tank? Thanks.  <Not so quick answer -- First, you are limited by what you have on your rock when you obtain it. Some are better than others. I must say that I remain astonished at the variety of stuff that grew off of my Lalo live rock from www.liveaquaria.com.  Second, you need to provide ideal conditions. Don't scrimp on salt. Use true oceanic salinity with a SG around 1.023-1.025. Keep temp and pH stable and in tropical ocean range. Keep ammonia and nitrites zero and minimize nitrates.  Third, do not allow nuisance algae (hair algae and bubble algae, for instance) and Aiptasia to thrive. That said, there are a number of beautiful red and green algae that can be grown in a controlled and attractive fashion.  The fourth step is the most important and most difficult. Be patient. Allow time for the organisms to thrive. Do not add predatory invertebrates and fish for several months. If you have the patience to wait at least six months to add anything, you will be amazed at what you can get to grow and thrive. You may want to carefully feed a quality invertebrate food like Cyclop-Eeze. Good luck.> 

Seeking marine macrophytes, WWM I'm having a hard time finding macro algae other than Caulerpa. No one can order it and so on... so right now I am looking at getting Red Halimeda, Mexican Caulerpa, Grape Caulerpa, Green (calciferous) Halimeda, and Prolifera out of all of these what will work the best for NNR. They will have their own 55 gallon refugium plumbed into a 135 soft coral tank. thanks a lot <No, thank you. Please read on WetWebMedia.com re Macro algae, Refugiums, Denitrification... use the search tool on the homepage... you need to. Bob Fenner>

Algae growth Good Morning, Should some algae growth be allowed to grow on the live rock for tangs, Centropyge angels etc. or should it be controlled thru the addition of urchins or other means?<a small cleanup crew and the tangs should take care of minimal to medium amounts of algae growth>  I have seen some aquariums with lots of algae growth but I am now sure this is good or bad.<I would clean the algae off of the glass and overflows and let small amounts grow on the LR>  I have some red and green both developing on my live rock.  But I have been brushing it off and have added two small urchins.<that's fine>  Which is the best way to have your aquarium? Let algae grow or remove it. <I just let some algae grow on my live rock and my tangs and angel pick it off, IanB> Thanks for you advice and look forward to your reply.  Have a good day. Ceil Wagaman

- Freshwater Algae for Marine Fish? - Hello, <Hello to you.> I was wondering if you could feed rocks covered with that green stringy algae that grows in freshwater to a marine fish such as an angelfish or tang? <I would think so.> Would it be bad for them or would they just not nibble at it? <Won't know for sure until you try it, but I'd be more concerned about the 'rocks' that held the algae... just concerned they may react with saltwater, depending on their origin.> I read on your site about growing your own rocks in the window in a jar with saltwater so I have started that but no algae yet, but I have tons of rocks with freshwater algae on them from my pond so I was wondering if I could use them in a marine setup. Would the algae just die off when put in saltwater and the water? <I think it would eventually, unless the fish eat it first.> Just curious. <I would try with just one, and have a water change waiting in the wings in case something unexpected happens... if the fish eat it, then you know you're on the right track. If the algae dissolves and discolors the water, do the water change and don't put in any more algae rocks.> Thanks for all of your help all of the time, you are an invaluable resource. Kylee <Cheers, J -- >

Reddish algae Hi Guys <<And hello to you, JasonC here...>> Since I don't believe a word that my LFS tells me and you guys have really been on the money with my other questions, I hope you don't mind some more. <<Not at all.>> I have a marine fish only tank that has been set up for 10 months. I am beginning to get some pinkish red algae on my skeletal coral for the first time. Is this normal? <<I wouldn't call it abnormal.>> What is it a result of? <<Natural processes and maturation of your system.>> What can I do to prevent it? <<Well, depending on what type of algae this is, you may not want to do anything. If this algae is truly pink or even lavender, then it is probably coralline which is highly prized by most reef keepers... there are too many candidates to list, check out this URL, I think you will find it helpful: http://www.wetwebmedia.com/algaeasfriend.htm >> Thanks as always Joe <<Cheers, J -- >>

Algae Control I have a 46 gallon aquarium. I have a magnum 350 filter, a 30 watt marine glow light and a half fluorescent and half actinic light. I have them on for 10 hours a day. I have 50 pounds of sand and 10 pounds of coral. I get a quick build up of brown algae. I have to scrap the sides of the tank weekly. Is this common or do I need to make some adjustments. <<It is common enough that I clean the glass on my tanks weekly as well, or sometimes not quite that often.>> I also have 40 pounds of live rock and 2 yellow tail damsels. Thank you very much for your help <<As long as you are only cleaning the glass, and the algae isn't taking over your system, I'd say no worries. If you are still concerned, you might read up here: http://www.wetwebmedia.com/algaeasfriend.htm  Cheers, J -- >>

New Print and eBook on Amazon

Marine Aquarium Algae Control

by Robert (Bob) Fenner

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