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FAQs about Red Calcareous and Coralline Algae Behavior 

Related Articles: Coralline Marine Algae, Red Algae in GeneralAvoiding 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 1Coralline Algae 2, Coralline Algae 3, Coralline Algae 4, Coralline Algae Identification, Coralline Algae Compatibility/Control, Coralline Algae Selection, Coralline Algae Systems, Coralline Algae Nutrition, Coralline Algae Disease, Coralline Algae Reproduction/Propagation, Red Algae in General, Red Algae 2, Red Algae 3, Red Algae Identification, Red Algae Behavior, Red Algae Compatibility, Red Algae Selection, Red Algae Systems, Red Algae Nutrition, Red Algae Disease, Red Algae Reproduction/Propagation, Marine Macro-Algae, Use in AquariumsMarine 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

Coralline algae       9/19/19
Gorgeous photo of coralline algae!! Ahhh. LOVE the stuff. One small thing. Although some or many coralline algae species do bind things together, they aren't absolutely critical in all reefs. Reefs and reef zones, vary in how much CCA there is, and some species don't even seem to bind things together. We've got a reef flat in American Samoa that's covered with loose rubble, been that way for decades, and it has a fair bit of CCA on it. CCA is indeed an important contributor to reef building, but varies in how much it contributes. Reef crests in the Indo-Pacific that are totally exposed are often 100% CCA. They're not studied much because they are pretty dangerous places, a person can get ripped to pieces out there, though sometimes you can walk around on them at low tide. I've done that. Some reefs that have high coral cover don't have much CCA. Some that have a lot of CCA don't have much coral. Some have both. At this point we know that some species of CCA attract larvae from some coral species. We don't know how widespread that is among CCA species or coral species (I hope it is widespread among coral species at least, but don't know). We also know that there are a few CCA species that can grow over coral and kill it. I have a few pictures of that, but I've never seen it be common.
Anyhow, some of us think that algae, including CCA and Halimeda, contribute enough to building reefs that maybe we should call them "coralgal reefs" instead of "coral reefs." grin.
Cheers, Doug
Douglas Fenner
Ocean Associates, Inc. Contractor
NOAA Fisheries Service
Pacific Islands Regional Office
PO Box 7390
Pago Pago, American Samoa 96799 USA
"Global warming is manifestly the foremost current threat to coral reefs, and must be addressed by the global community if reefs as we know them will have any chance to persist." Williams et al, 2019, Frontiers in Marine Science

A call to climate action (Science editorial)

New book "The Uninhabitable Earth" First sentence: "It is much, much worse than you think."
Read first (short) chapter open access: https://www.pbs.org/newshour/arts/read-a-chapter-from-the-uninhabitable-earth-a-dire-warning-on-climate-change
<Thank you for this note/addenda Doug. Would it be okay to share on WetWebMedia.com?

Re: coralline algae       9/19/19

SURE!!!! Thanks so much for spreading word like this! If there are topics you'd like me to cover, I may be able to do that as well. Cheers, Doug
<Ah my friend (and likely distant relative)! What might I do to encourage you to branch into the ornamental aquatics (dare I say "petfish") content provision fields?
I will gladly encourage you to write, help make submissions to the pulp and e-zines in the field.

Re: vacuuming gravel, Now Saltwater Tanks, Coralline 3/3/10
Hello again,
This time I have a question about my saltwater tank.
It's a fowlr system - 46 gal. - been running about 7 months - 350 Marineland penguin filter.
<No skimmer?>
1 black molly
1 royal gramma
1 maroon clownfish
<Will probably need a new tank, or may kill off all other fish as it matures.>
1 scooter blenny
<Needs a larger tank.>
1 coral beauty
<Also needs a larger tank.>
1 pajama cardinal
<Watch carefully for signs of harassment.>
1 turbo snail
2 other snails
about 10 dwarf blue-legged hermit crabs
The coralline algae growing is green - why?
<Something favors the green variety, most likely the lighting strength or color.>
Is it because of the lighting? - zoo med reef light (50/50 combination of 6500k Trichromatic daylight phosphor and actinic 420 phosphor)
Can the color be changed?
<You may be able to encourage other shades to grow, but there is no guide as to what shades are favored by what lighting as far as I am aware.>

Coralline algae question 07/17/2008 Hi <<Good Morning, Andrew (the ghost) here today>> my 75g tank has been running successfully for more than a year with excellent coralline growth. Lately, however, some of the coralline on the back glass has been flaking off, sort of like old paint. It has not bleached and appears to be completely healthy even after falling to the bottom. New patches of coralline quickly colonize the bare glass. And there is no sign of coralline flaking off the rocks. Is this normal? My water parameters: 78-79 degrees, pH 8.0-8.1, dKH 12, Ca 375-400, barely detectable nitrate levels. I am running a Korallin calcium reactor and a Precision Marine Kalk reactor on the top off. I employ an AquaC EV-120, 2x175w 10000K MHs, and 130w of actinic PCs. I only supplement iodine. The only grazers are Turbos and a rabbitfish. <<Certainly nothing to worry about. The time to worry would be when the coralline does not grow back. Experienced this myself a few times>> My first instinct is that this is exactly what coralline algae probably does in the wild, and the smooth glass is probably the easiest surface for the algae to lose its grip on. But I was curious to know if you had seen anything similar before. I hate to rely solely on instinct. Thanks! <<As above, yes, had this myself, and its nothing to worry about>> Ed <<Thanks for the questions, hope this helps. A Nixon>>

Coralline with white buds? -- 08/31/07 Hi, <Hello there> Does anyone know what could be going on with this coralline algae? <Rapid growth, calcification mostly> (pics attached) These white buds popped up out of know where. Could it be spawning? <Mmm, not by these structures, but yes> Does coralline algae spawn? <Oh yes... alternation of generations like all thallophytes... sexual and not... BobF> Thanks, Sara

Re: Red Coralline w/ whitish buds   9/1/07 Hi, Crew. I read this message and saw the picture. This looks *exactly* like what my reef tank looked like when I had an outbreak of Asterina starfish. <Hmm... I don't have many of these stars. In fact (since I like them) I've been trying to get them to multiply more in my refugium. And yet I still can't find more than a dozen or so of them.> My guess is that the feeding behavior (stomach inversion) of the stars was causing bleaching. Water changes, food reduction, and other nutrient control techniques "reduced the plague", and the problem went away. <Interesting theory, but I don't have noticeable problems with nutrients. I don't have other algae, Aiptasia, or any other such problems. Even these white spots are only in this one spot.> Just wanted to share. <Thanks you for your thoughts and adviser. But, at least for now, Mr. Fenner's theory makes the most sense to me. I'll let him respond if he thinks you might be on to something.> Dan
Sara M.>


Live Rock Turning White 10/18/05 Hi guys, <Hey, Mike G with you this evening.> I have a question about the 79 lbs of Live Rock in my 75 gallon tank, it is turning whitish in color, do you guys know why? <Coralline die off. Coralline algae is a benign, desirable calcareous algae that grows in profusion in established aquaria and on the reefs of the world. It comes in a vast array of colors, all in the Red-Purple-Orange area. Often, new aquaria do not possess the facilities to properly care for this algae, and it dies off, leaving behind its (white) skeletal remains.> I had heard that this means that your live rock is dying or decaying, but It has been in there for about 5 weeks and is fully cycled, it was really flourishing until I noticed a few areas of the rock turning white, it isn't all white yet though.... In the tank I have a Neon Goby, 2 ocellaris clowns, 3 blue green chromis, and a twin spot goby, all of the fish are doing great. here are my water parameters: Nitrate: 10 <Decent.> Nitrite: 0 Ammonia: 0 pH: 8.3 Salinity: 1.025 <Good.> Calcium: 350 <Low, could be a factor in the coralline die off.> Alkalinity: 10 <A bit low.> Temperature: 80.5 <Fine.> I just did a 12 gallon water change about 4 days ago, anything else I should be testing, or do you see why this would be happening? <See above.> Also, the surface of my water looks like it has oil in it <Common problem. Get a powerhead to agitate the surface, no real way to prevent it.> I use RO/DI water for water changes so I don't know why this would be <Dust, etc. from the air.> but like I said everything other than the rock is doing great. <As should be expected.> Any insights, thoughts, ideas, or actions you tell me to take are greatly appreciated :) Thanks, <No problem.> Clare <Mike G>

Pink Coralline algae turning white 11/4/03  Hello, Any ideas on why Pink Coralline algae would turn white?  Thanks. Teddi  <the list of possible reasons is very long. Common causes though are inconsistent Calcium and Alkalinity levels, lack of water changes (only monthly or less often), light shock from new lamps or a water level drop (as with water change) with lights mistakenly left on (Yikes! bad - bleaches corallines)... temperature shocks too. Many possibilities. Anthony> 

Why is Fiji coralline algae so PURPLE? Greetings again, esteemed fellow wet-heads. I'm about to set-up a larger reef tank, which will focus on "Indo-Pacific" livestock, especially those from Fiji. So that I can make life as comfortable as possible for all future inhabitants of the tank, I'm trying to find out what environmental factors make Fiji live-rock coralline algae so predominantly PURPLE? I'm not merely jazzed about the color -- my hope is that creating a tank which favors purple corallines from Fiji would benefit other creatures from the same neighborhood (duh). Is there some special combination of water quality, lighting, and water chemistry (trace elements? calcium characteristics? oxygen?) that makes Fiji live-rock so purple? <Wish I knew... have not seen discussed this particular issue> My instinct is that, in addition to the above criteria, WATER DEPTH (i.e., resultant lighting spectrum) plays a large part in favoring "the color purple." Hypotheses: Does Fiji live-rock get unusually high "actinic" radiation? UV? Or is the surrounding water rich in some specific mineral? <Don't think so on these counts. Have been to the areas where the companies collect most all the LR in Fiji... it's large, open, shallow (wading depth) seashore to the open Pacific (along the Coral Coast in Viti Levu) for the most part... Perhaps their greater care in cleaning, shipping LR has something to do with it... and there is notably a dearth of hermits, Parrotfishes in and about these collecting areas... maybe this has something to do with the propensity for corallines> My existing tank has provided consistent growth of a VARIETY of coralline colors, which is encouraging but means I need to fine-tune a bit before embarking for Fiji. THANKS in advance! - Bruce Mewhinney <Look to using a system of checking, providing adequate to excess biominerals AND alkalinity to boost your encrusting algal growth... Bob Fenner>

Algae in FOWLR 2/5/04  Good morning, just a quick question regarding algae growth. I have a 220 gallon FOWLR system with about 150 pounds of live rock. When I purchased the rock it had nice purple, red, violet coralline algae. A few of the pieces had a very very dark red color. This dark red, almost black looking seems to now be growing on the majority of the rocks and over top of the other more colorful encrusted algae. This growth I speak of looks slimy yet is hard. Is there anything I can do to promote other colors and types? I don't have any blue actinic in my power compacts, would this make a difference?, is this a good alga or is it telling me something is wrong with my system?  <Different coralline algaes will dominate depending on many factors including lighting, current, calcium, magnesium, and alkalinity. Increasing the current and maintaining calcium and alkalinity are the most important factors in promoting growth of a variety of corallines, but on may still dominate. Adding some actinic light may favor a different type than you have now. I don't think anything is "wrong", but do test the calcium and alkalinity. Both of these parameters are often ignored in FO tanks, but should be maintained if good coralline growth is desired.>  One thing I should mention is that I have in the past dropped the salinity in the system to fight off Ich. I've since moved it back up.  <A drop in salinity could have contributed to the die off of some corallines. Hyposalinity is hard on live rock all the way around because it is very stressful on all of the inverts living in/on the rock. I like hyposalinity very much, but it should be used in quarantine.>  Last question I do have a clown trigger in the tank, if I was to get some turbo snails to help eat the algae is it likely the trigger would eat the snails. Thanks for the help. Joe  <This may be hit or miss. I would give it a shot with a couple of snails and see if the trigger behaves before adding more. Best regards. Adam>

- Coralline Algae Not Growing - Hi crew, thanks for all your help in the past.  I just passed my one year anniversary on my 55 gallon reef/ 30 gallon sump with "fuge".  Things are pretty good and I'm getting more sophisticated in knowledge and husbandry. So far I have two fish, flame angel and tomato clown both doing great.  One corkscrew anemone who has doubled in size, a couple of mushrooms and some clean-up guys.  My question has to do with why my coralline just won't grow. Tank specs: Temp = 77.9 SG = 1.025 PH = 8.2 - 8.3 Calcium = 400 Alk = 2.8 meq/l Magnesium = 1200 ORP = 297 - 327 (8 hour swing) Nitrate = 2.5 Phosphate = .125 Ammonia = 0 Nitrite = 0 Lighting = 3-4 watts per gallon VHO CPR BakPak = 1/2 cup per day output Kalk drip = 3 gallon DI top-off every two days with 3 tsp of Kalk covers daily demand. Iodine = 1 tsp per week Water change = 10 gallon per week No other supplements, I feed very sparingly.  My coralline just won't grow, I had read that some hermits eat coralline so I moved them all into the "fuge".  Also quite a bit of slime algae growing in sump. I ordered an ozonizer to install into the venturi of my skimmer hoping to get ORP up around 400 Mv. Also ordered some red Gracilaria macro for sump. Are there any parameters or things I need to tweak or am I missing something completely. <Hmm... Kalkwasser alone will do nothing for you alkalinity, which is low based on the numbers you provide. You need to work at improving that number and that will improve calcium uptake by the coralline. More about calcium/alkalinity here: http://www.wetwebmedia.com/calcalkmar.htm > Kind of at a loss here, I read the GARF stuff, still no results. As always thank you in advance for you help  Mike <Cheers, J -- >

Question on Coralline Bob, <Msieu Moore> I was a regular user of a website that allowed folks to ask you questions on their tanks.  That site has now merged with Dr. Forster and Smith and they don't offer that service.  Since I saw your name associated with another site I thought I'd take a chance and shoot you a question.   <Glad you found us... WetWebMedia.com continues as our archive> My coralline algae is looking like someone sprinkled sugar on it.  I'm not sure if this is a bad thing or not but I'm hoping you've heard of it and might have a reason for the cause. Thanks for your time. Keitt Moore <Likely either calcium is out of balance with magnesium (should be in a ratio of about 1:3) or your alkalinity is low. Do test for all, and adjust accordingly. Bob Fenner>

Coralline Algae 24 Jan 2005 Aloha WWM crew, <Aloha Richmond, MacL here with you this morning.> I was wondering if the color crust on my turbo shell is coralline? <That would be an affirmative.>  If so, could any of the algae on my rock in picture 2 be coralline?  <EEK I didn't see picture two, just picture one but I'm guessing that it could be. Coralline is very hard to the touch an actually hard to remove.>  How can I go about in promoting coralline growth and detour the others from competing with it?  <Coralline generally shows up on something, on the sides, on the rocks etc. It needs calcium to flourish.> The 3rd picture is a old empty turbo shell that has brown hair like algae and some kind of brown fuzz rug on it. Is this type of algae anyway good and how do I go on about of getting rid of it if it comes a problem? <Honestly I would pull it out right now and pull all of it off. That algae is terribly difficult to get rid of and it won't hurt the empty shell to just pull it out of the water.> Currently I quarantined my blue tang, yellow tang, 2 yellow tail damsel, fire damsel and clown fish because the tangs had a little outbreak of ich. The tank has been running with only 4 brittle stars, 4 Turbos and a cleaner shrimp. It's been a little over a week and my pod has 4x its population but then these brown hair started showing up as well.  <No tangs to eat it would be my guess. As soon as they go back it should all disappear but you don't want to let it get ahead of you.> I've also notice some of my pods are turning red or maybe this is a stage in growth? I saw one of the red pods attached to another pod then two more pods attached on to the red pod...eventually the other 2 let go but I don't know what happen to the pod with the red pod on it.  <I've never seen one that has red on it but its not out of the realm of possibilities.> Lastly, I was thinking about removing the filter trays and just left my sand rack and use the filter as water current to move the water, is that a good idea? I figured that those filter only trap poop and other debris and I could just buy a separate carbon pouch if needed.  <I'm assuming you have lots of live sand and live rock in the tank to work as your filter instead? Should be okay if so. Lots of circulation is important to the tank.> 

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