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FAQs on Marine Algae and Their Control 21

Related Articles: Avoiding Algae Problems in Marine System, Algae Control, Marine Maintenance, 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: Marine Algae Control FAQs 1, Marine Algae Control 2, Marine Algae Control 3, Marine Algae Control 4, Marine Algae Control 5, Marine Algae Control 6, Marine Algae Control 7, Marine Algae Control 8, Marine Algae Control 9, Marine Algae Control 10, Marine Algae Control 11, Marine Algae Control 12, Marine Algae Control 13, Marine Algae Control 14, Marine Algae Control 15, SW Algae Control 16, SW Algae Control 17, SW Algae Control 18, SW Algae Control 19, SW Algae Control 20, Marine Algicide Use, Nutrient Limitation, Marine Algae Eaters, Culturing Macro-Algae; Controlling: BGA/Cyano, Red/Encrusting Algae, Green Algae, Brown/Diatom Algae, Phosphate

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Marine Aquarium Algae Control

by Robert (Bob) Fenner

Mature Tanks - Diatom Bloom      4/24/20
Good afternoon!
<Hello Dave!>
I'm frustrated to the point of wanting to take a hammer to my tank (ok not quite yet)
<Ahh!, been there several times in the past 30 years, this hobby demands patience>
Going on 18yrs in the hobby, and I had a previous 90g reef tank and 200g predator tank running beautifully without issues after a 3yr trial and error period. With a move, I gave up the other tanks and now have a 60g reef. I very quickly seemed to have that tank under control within the first year, but at the start of year three I used some chaeto from a local fellow hobbyist that seemed to be plagued with bryopsis. Within two weeks of using his chaeto, there was nasty green algae everywhere...
took a while to figure out it was bryopsis, and I soon had that under control with fluconazole. Since then, I've been getting what appears to be diatom algae.
It's not cyano. I <It> starts on my sand bed at the front of the tank, and then shows up on some of the surfaces of my rock where I don't have corals.
<Is it present even on the shaded areas?... have you seen any small air bubbles on the top of the sand or rocks where it has grown?>
I use RODI, have changed filters on schedule, and my source water readings are Ammonia, Nitrate, Nitrite, Phosphate all 0 readings.
<What about Ph?>
I was suspicious of the Phosphate test and bought a Hanna, and confirmed it was in fact a zero reading. I'm confident my source water is good.
Feeding... two Clowns, a Foxface, Royal Gramma, Peppermint Shrimp, Cleaner Shrimp, Sebae Anemone, Banded Serpent Star, maybe 20 blue legged hermits, 5 Nassarius Snails, and four other assorted snails. Frogspawn, Colt, assorted Zoas, and a Toadstool. I figure I have a relatively light load for a 60g tank.
I feed half a cube of frozen 4 times a week, and pellet 3 times a week - just enough that it's all consumed. I think if anything I am feeding light, my Foxface could use some additional weight.
Other nutrient control: skimmer that produces some pretty wet skim and it's hard to adjust properly.
<A good, reliable protein skimmer is very helpful in maintaining top water quality.>
It definitely could be better, but then again I have a very light load I think.
I have chaeto in a refugium that grows like crazy I rinse and garbage a 1/3 of this every week during water changes that are 10%/week. My tank water parameters are ammonia, nitrite, and phosphate 0. My nitrate will sometimes give me a small reading of 0ppm to 10ppm, which I think is fairly normal and healthy? I also have one filter sock that I change weekly.
<Well, since your tank seems to have a very low nutrient source, I am thinking these could be Dinos (dinoflagellates), which prosper in the absence of nutrients.>
Lighting... I have two Kessil 360's 8" off the water that run from noon to 10pm.
They start and stop with about a 90min blue and 0% intensity schedule, and the 2hr ramp up/down period hits a peak of 45% intensity and sits there for 3hrs before dropping (7hrs all together), I'm adding 55% color on the same schedule. I do get about 40mins of direct sunlight on the side of my tank from a huge window, but I figure in conjunction with a 7hr light schedule where I apply my color/intensity that this shouldn't result in my diatom algae? Again, I ran the tank for a year algae free on a similar light schedule (I wish I had kept the specs on that schedule – it was since adjusted for various coral placement, etc.)
I remove all noticeable diatoms (that eventually start growing green hair) with my water changes. I have conducted two full 3 day blackout periods in the past two months, and still this all comes back.
<Worth trying a 5- day, to a whole week blackout, covering the tank with cardboard and allowing no light at all, natural or artificial.>
I can't seem to figure this tank out. I was watching 52 weeks of reefing on YouTube and the clean-up crew video where they indicated too many snails/crabs can lead to algae because there isn't enough food for them all, they die, and leads to excessive nutrients. What peaked my interest is that I have thousands of those tiny little pebble snails (what are they called?).
Could the birth and die-off of these little guys be causing a problem? Seems unlikely
<Only if they die massively>
The algae starts only in certain spots, and then will slowly spread... always starting in the same spots. My two return pumps each have a splitter for two directional flows (4 total) and they circulate my tank volume maybe 15 - 20x/hour. Additionally, I have one MP40 on a random setting. I know water flow will help with cyano, but it seems odd this diatom algae starts growing right along the front of my tank in the path of my MP40.
Does anything stand out to you as a probable cause of this algae issue?
<Yes, from your description, and the way things happened, I am almost sure these are dinoflagellates, which were introduced to your system via the Chaetomorpha.>
With the algae starting on the bare rock and in the front of the tank where
it receives the most light, I keep going back to my lights. Thoughts?
<I suggest the following:
1- Trim your chaeto to about half and see if Dinos start to disappear over the course of a week or two in the presence of some nitrates and phosphates.
2- Siphon out regularly the top layer of the sand, where the majority of the algae is located .
3- A high ph around 8.4 seems to inhibit Dinos proliferation, I don’t know your current reading, but it will help if you aim for the mentioned number, go slow with any changes.
4- Leave only the blue lights on for 6 hrs./day, for one week (Dinos like the white spectrum).
5- Consider adding a DSB to your refugium
6- If possible add a UV sterilizer.

I hope this helps. Wil.>

Does this look like Cyano to you?

Re: Mature Tanks - Diatom Bloom    4/25/20
Thank you for the response, Wil.
Not sure if you got my attached photos?
<I did,... are already posted on the daily FAQs. The only way to be absolutely sure of the type of “Algae”, is to take a sample and see it under a microscope, many look pretty much alike, that’s why we have to rely on the antecedents of the particular system.>
A little more info on the timeline...
I had a perfectly beautiful tank and went to Europe for 4 weeks on vacation while a friend monitored the tank with water top-offs and feeding. I returned to chaos and a mess of a tank. Algae everywhere. Some water changes, etc... I had it looking good again and my chaeto that I had at the time had turned black so I tossed it. I ran without chaeto for awhile, and my nitrates then increased from 0 to as much as 30 or so ppm, and it seemed my corals were suffering. I then purchased some chaeto from the hobbyist and had the bryopsis outbreak very soon after. I fairly quickly resolved the bryopsis outbreak with fluconazole, but then started to experience the diatom algae and had some nitrates in the 20ppm range. I just recently added the good batch of chaeto and it has resolved my nitrate issue, and finally my corals are looking good... but the diatoms are still there.
Thus, I hear what you're saying... but the Dino was present even when my nitrates were in the 20ppm range.
To answer your questions:
It first looks like a rusty dusting over sandbed and then rocks. There might be the smallest of bubbles that form followed by green hair algae. It is not present in shaded areas, no.
<Those are indicators of Dino infestation.>
Ph is consistent at 8.2 since I started the tank
The tank is an Innovative Marine, thus the sump is actually the back portion of the tank. If I add anything back there, it'll be a bitch to ever get it out...
<Understood, it’s impractical to add a DSB there.>
but I hear what you're saying. On my old 90g reef, I had a deep sandbed in my refugium and my setup was pretty slick and trouble free - never even had to clean the glass of algae.
<That’s why I suggested that.>
If I alter my lighting to 6hrs a day with more blue (on these Kessils there's only a percentage setting, so I am assume I just keep my color around 20% or less?), do you think I should keep my intensity as is?
<The bluest spectrum your Kessils provide is okay, just don’t use the light spectrum on the lower Kelvins range.>
Do you perceive any coral impact to a color adjustment?
<Not too much as this is going to be temporary.>
As far as equipment, on a scale of 1-10 I'd rank my Innovative Marine skimmer around a 6.
<Yes, the biggest drawback is that it is very difficult, almost impossible to fine tune.>
I do get wet skim and bubbles constantly, but then again I wonder if it's because the tank is fairly clean?
<Could be>
Investing in presumably a better skimmer vs adding a uv sterilizer. Go with the UV Sterilizer?
<For now, I’d go for the UV to kill any floating micro-organisms that are causing this issue. Wil.>

Coralline Algae, Cyano, or ???     8/3/19
Hi Bob -
I am stumped trying to figure out exactly what's growing on my glass and rocks in my 265 gallon FOWLR tank. I've attached a few pictures. It doesn't come off very easily at all. Frankly, to get it off the glass you have to use a scraper with some force, then to get it off the rocks, good luck as a tooth brush will very slightly thin it out, but if I really wanted it off, more likely it would take a steel brush with some force to get it off the rocks. Further, when I scrap it with force off the glass it comes off as a dust, not in sheets.
Thus, based upon this hard consistency my gut tells me it's Coralline Algae, yet I am used to Coralline algae being pink or light purple, not red in color. It's a dark, burgundy red, similar in color to cyanobacteria, but I definitely can't siphon it out like you can with cyanobacteria. Should I be concerned?
Thank you,
<Hey John. Coralline (encrusting Reds, Rhodophytes) are very different to the touch than Blue Green "algae"/Cyano... The latter are slimy; and of many different colors. Reds are not slimy, but hard, crusty... From your description and photos this appears to be BGA...
Yes to being concerned... conditions that allow, encourage BGA are deleterious to most all other life forms as are some of the metabolites of Cyanobacteria.
Please read here re the several approaches to control: http://www.wetwebmedia.com/bluegralgae.htm
and the linked BGA Control FAQs above. Bob Fenner>

Re: Coralline Algae, Cyano, or ???     8/4/19
Ugh. Terrific article. Thanks Bob!
<Cheers John! BGA is defeat-able, avoidable... Like steering a large ship w/ a small rudder; takes a while, but... slow and steady is the route to go. BobF>

Boron and Cyano relationship      6/27/19
Hey guys sorry to bother
<Hey Tom, no bother at all.>
but we have been sending water samples to ICP labs and when ever our boron level seems to increase to about 40
<40 what??... Typical values in nature are 4-5 ppm while in aquarium systems can be higher.>
you know it’s a very drastic increase in Cyano in normally pristine Systems we also noticed that when I was boron level increases our Coraline bleaches and flakes off the walls
<It may have to do with your salt, although normally it does not come in high levels in the salt mixes commonly used for aquariums, so , it could be more related to buffer additives, do you use any?...I wouldn’t worry, IF your B level is in the normal range. You can return the Boron to safe levels via water changes.>
Never knew that Boron was that important and that detrimental to both of these.
<Oh, yes, could be an issue if it gets off the charts. Thanks for sharing. Wil.>

Algae ID     6/25/19
Good morning from Thailand,
<Hi Dirk from Thailand!>
I have attached some pictures of some algae I am getting very frustrated in and seem to be taking over this aquarium for the longest time now. Aquarium has no fish inside and only houses 2 seahorses which are only fed live brine shrimp and copepods. No food added ever to this tank for about 1year++Water tests show 0 Nitrates and 0 Phosphates. Top off is done with RO/DI water, I dont have silicate test kit so not sure if that's available. Have been putting phosphate remover in the aquarium added extra bacteria to try and out compete this algae but .....Shut of the lights for several days which seem to effect them slightly to just return in force as soon as light goes on. Tank has also a large toadstool, 2 elegances and some red ear and branch sponges.
<What are the dimensions of your system, water volume?... also, what type of filtration do you have, do you run a protein skimmer, ozonizer? These last two help by limiting nutrient availability which is used by BGA (blue-green algae) to reproduce.>
We have tried everything even at one point removing all stone cleaning them removing daily manually, phosphate remover......but this thing keep going and going.....added blue legged hermits, Turbos, Algae crabs, had a Seahare in it even for a while....
<Do you have a sump?... a DSB with macro algae in a reverse light cycle really helps on getting rid of this nuisance algae.>
Cant really seem to find any positive ID on the net either maybe you guys can help?
<This appears to be BGA (blue-green algae).>
thank you for any advice possible...
<You’re most welcome. Wil.>

Re: Algae ID     6/25/19
Hi Mister Will,
Blue green algae are they not to be Cyano bacteria rather then algae?
<Yes, that is how it is called and it is either blue, green, red or brown.>
Not sure if you noticed what I send on the pictures but what I am referring to what is taking over my tank is not a bacteria but rather a green looking plant....see again attached picture with marked what I referring to.
< Yep, it is BGA.>
As for the system yes a skimmer is present in the system though no extra space for a refugium is available.
<I suggest you to perform a large 30% water change, followed by weekly 10% until the problem is solved, please see the following link and related ones. http://www.wetwebmedia.com/cyanocontrolfaqs.htm . Wil.>

Tank Upgrade - Algae Issues   6/4/19
Good Morning,
How are you?
<Fine Brent, thanks.>
I have had my 30-gallon reef set up for a year and a half. Over the next 2/3 weeks I will be transferring to a 90 gallon.
<Nice upgrade!>
Over the last 3 months my 30 gallon is experiencing a bad outbreak of bri<y>opsis and Cyano. It has completely overtaken my rock and corals.. I have not done much about it aside from water changes because I knew I would be upgrading.
<Mmm... Nutrients must have been accumulating due to the lack of water changes.>
The Bryopsis came in on a frag I purchased from a local reefer. I didn't check the coral, I just put it in. So, my excitement/laziness got me in this pickle.
<Ahhh...laziness and anxiety always make us to double work at the end.>
My plan is to use the LR and put in in the sump to help the 90-gallon cycle quicker (if their would be a cycle due to transferring sand and water as well)...
My question is, Would you advise I use any of the rock, sand & water for the 30 or start from scratch to eliminate the algae issues I have been having?
<You can use all the rock after slightly rinsing it with old tank water and brushing the rocks covered with Bryopsis; I wouldn’t use the sand without rinsing it, again... with old tank water; you may use the water from the 30-gallon when the 90-gallon is fully cycled to slowly acclimate your tank inhabitants to their new environment.>
Thank you,
Brent Krahn
<You’re welcome. Wil.>

Ostreopsis & UV... Re Dinoflagellates, control     4/21/19
Howdy again, I’m back with my battle against the Dinoflagellates. I hope I’m not jinxing myself with this. But I think we are turning a corner. I hope to meet y’all at MACNA this year, for the third time, and not ask you about Dinoflagellates.
(This post is mostly informational for anyone reading).
<Heeee; okay!>
Very important to ID what you are fighting, my experience is with Ostreopsis and the battle is different for different kinds of Dinoflagellates. You can get a good microscope for about 100 bucks.
<Ah yes>
What did I try.
1. Blackouts. Only temporary relief.
2. Introduce good stuff from someone else’s tank. Some help for a while.
3. Dirty method. Get your tank good and dirty to encourage the growth of something to compete with the Dinoflagellates. Moderate help.
4. One “Natural” supplement. Nada.
5. Hi flow, these things seem to like high flow.
6. Low flow. Better the Dinoflagellates release into the water column (good to know for later)
7. Ozone. Made our water pretty, didn’t help the Dinoflagellate problem at all.
<Interesting... re the latter; do, did you measure ORP/RedOx?>
Finally I stumbled on a very long thread where people have been documenting their results, on R2R.( https://www.reef2reef.com/threads/dinoflagellates-%E2%80%93-are-you-tired-of-battling-altogether.293318/page-356).
The point that resonated is that Ostreopsis will release into the water column making them more susceptible to UV than Ozone. The recommendation was 1w pert 3g. I added a Jebao 55w UV to my 300g. I simply cannot fit a 110 under my cabinet.
I also decide to try the Prodibio bioptim/biodigest (what did I have to lose).
The combination of these seems to be working. I did my first W/C in quite a while, so time will tell if they come back.
I must admit I miss the ozone. I do have a question. It seems to me that running UV & ozone, alternating days or something, would be bad.
<Mmm; bad? Can be done... UV's of worth do produce a modicum of 03....>
The UV doesn’t seem to do much for water clarity and the ozone doesn’t control my Dinoflagellates. Also, is it reasonable to assume that I will need to keep the UV running in my system permanently? I’ll look into those at MACNA this year.
<I'd run both, either (UV or ozone) continuously. The ozonizer in conjunction w/ a monitor, regulator or undersized/powered to keen ambient down, below 400 micro-siemens/cm. >
Thanks for all your help over the years.
William Anderson
<Thank you for sharing Will. Bob Fenner>

Re: I'm back in the hobby! Cyano issue       12/11/18
Hello Bob and Team,
<Howsit Gene?>
I'm fighting Cyano (I think). Tank was established in July 2018. Small tank...45 gallon AIO. Running UV and skimmer.
<Mmm; these last two should help (indirectly) by limiting nutrient availability, raising RedOx, zapping and removing free-floating forms, spores>
Vacuumed the sand bed really well today tanking out the top layer of nasty looking sand. Running Purigen and ChemiPure Elite in two chambers in the back (one in each chamber).
<Good moves>
Nitrates = 0 (using a lousy API kit).
<Mmm; lo dudo>
Phosphates = .021 (using the ultra low Hanna digital meter).
I don't feed heavily and try to run lights at 10K for only 2 hours around noon. Other times running LED blue to show off the corals.
<Mmm; well, you might be better off w/ more light here. Convert the BGA to Greens, other Divisions of algae. Do you have some purposeful algae culture going here? Any room for a sump/refugium, DSB, RDP light set up?>
Fish and corals all seem to be doing well.
Fish = 2 clowns, 3 cardinals, 1 coral beauty, 1 royal gramma, and 1 Rainford goby.
Added a cucumber and conch -- they don't seem to do much.
pH runs about 7.9 with Alk at 7.7
<Yikes; I'd be buffering your new/make up water to boost the pH here... to at least 8.2>
Any additional recommendations are welcome.
PS Bob recommended an additional Rainford Goby -- one of my 2 LFS (ain't this sad) was out and I only buy Rainford's from Biota.
<Okay! Have you reviewed re marine algae control on WWM?: http://www.wetwebmedia.com/algaeconMar.htm
and the linked files above? Caution: You can/may sucked into a/the WWM black hole of reading! BobF>
Re: I'm back in the hobby!      12/11/18
Thanks for the prompt reply!
Darn, I'm confused. Some say less light -- you say more.
<Think about this... too little, or low light encourages a different group (Divisions are the equivalent of zoological Phyla) of algae; Blue Greens/aka Cyanobacteria are greatly favored under little light circumstances, whereas Greens prefer bright, long-light days. You WANT to encourage the latter, discourage the former. YES, if there's too much easily available (soluble) nutrient available, little water circulation.... BGA will proliferate under broader conditions including more light>
I've attached a pdf of the light I have. It's a bit old but I can program it within the limits of the LEDs of course.
<This is a very nice fixture. Again, I would leave it on 8-10 hours/day; See/READ on WWM re>
I read the linked article on algae.
<Ah good>
Excellent and really pretty easy to read for the novice (like me).
I loved the statement: "I take exception with most authors on the virtue of one salt mix over, etc...." I completely agree.
I do use Instant Ocean (seems to work for most folks)
<Around the world this brand IS the category killer, used exclusively in some public aquariums, e.g. Georgia>
-- and as you noted, my pH is on the low side.
I've really never had much success raising it and maintaining it (the pH that is :)
<Mmm; well; you could/might use the I.O. reef mix... has more alkalinity; but I'd just blend in some of SeaChem's line in w/ your new/change out water: https://www.seachem.com/marine-buffer.php
I thought regular water changes would do the trick since I think IO salt mix mixes at about 8.3
I do have the Brightwell 2-part additives -- but, so far I've been sloppy about dosing on a regular basis.
Sorry, adding a sump is not an option for my setup. This AIO tank has truly been a challenge for me. I had a 125g with 30g sump in Atlanta -- dang it was easy to maintain. This 45g tank is much more difficult -- as I knew it would be -- especially without a refugium!
<Ah, yes... bigger systems are much easier to keep stable, optimized; and am a HUGE fan of refugium use>
You guys are truly a great resource. I genuinely appreciate your time to coach me along this renewed & new endeavor. I WILL GET THIS RIGHT.....!
PS Oh, BTW, I may have mentioned at some point that I did treat my tank with Boyd's Chemiclean. It worked the first time I used it -- but, the problem returned. I tried it again, but not with the same degree of success. I do not plan to use it again since I think it's only a band-aid and not the solution!
<As you'll find, I am NOT a fan of such "algicide" use... They really don't work unless the conditions that allow/ed pest algae profusion are addressed, and too-often they poison the water, inhabitants indirectly.
Be of good life Gene (Anima bona fac). Bob Fenner>

Re: Cyano control       12/12/18
Thanks, Bob.
So, am I clear on your recommendation: Use Seachem's Marine Buffer to increase the pH of the water I use when I do a water change -- thus, raising my pH slowly.
<Yes; mix it in with your pre-made and stored change out/new water>
Actually, from the research I've done IO salt does not mix at 8.3 but more like 7.9. I will begin dosing Polyp Lab ONE tonight. It simplifies the 2-part approach by having all key elements (dKH, Calcium and Mg) in one. I think the Brightwell 2-part I have been using does not include Mg -- thus, no coralline algae for me :(
Also, I will review my light schedule per your comments.
My best,
<Cheers! BobF>

Hydrogen peroxide; use for BGA control      10/27/18
Good afternoon Bob.
<Hey John>
Hope all is well. I’d like your input on the method of treating Cyano with HP. First, I completely understand the importance of addressing the root cause of the problem.
<Ah yes; good>
I’m working on it. However, in the mean time I would like to know if HP is a safe and effective way to deal with the outbreak.
<Can be... a "cheap" one-shot way to raise RedOx... of all things was just chatting this (H2O2 use for diminishing BGA last night w/ friend JoyB at the SDMA club meeting!>
My tank is 750 gallons with a sump holding approx 60-70 additional gallons. I keep mostly sps. I do have some lps as well as a extra large Devi’s hand and toadstool. Several fish as well. Do you support dosing peroxide 3% in a mixed reef?
<Again; at times, yes. IS your Cyano "that bad"? You have tried other means? Best are increasing circulation, Ozone, UV... diminishing nutrient influx, increasing removal like w/ the use of GAC...>
If so, could you please advise on how many ml per gallon and the frequency of dosing?
<A guess that works out often is 1 ml. per ten actual gallons of system water (deduct for decor, substrate...) of 3% solution. Some folks continue to add... about half a dose in AMs, PMs...>
As always I appreciate your expertise.
Thank you,
<Best done in conjunction with an ORP meter; keeping the reading under 400 micro-siemens/cm. Bob Fenner>
Re: Hydrogen peroxide       11/1/18

Thank you. I dint know how I missed your reply, I just found it. So just to clarify, is the HP approach supposed to be a onetime thing or do hobbyists continue to dose daily until the Cyano is gone.
<Many dose daily...>
I did see where you mentioned follow up does at 50% afterworlds.
<? words?>
Is that a maintenance dose or for continuation of the original problem?
<... you should study re RedOx, ORP....>
My main concern is my sps coral. I just want to make sure this is a safe approach (given correct dosing) for coral and other inverts.
<Most of the time; better by measuring microsiemens per cm.>
Oh, also, just to be clear, you are referring to dosing the HP in the water column and not spot treating with a syringe right?
<... yes>
And to answer your question , yes, at the moment it is really bad. My entire sand bed is covered as well as several pieces of rock.
<.... have you read on WWM re BGA?>
Not sure where things went wrong. I’m still tracking it. GFO, ozone and UV is running and I have pretty good flow.
I was waiting several weeks thinking it would burn itself out, but it’s not. I suspect that maybe I did a 150 gallon change with water high in po4 or maybe some bad salt mix.
<Could be a factor!>
Thank you very much for your time!
<So glad to discourse w/ you. BobF>
Re: Hydrogen peroxide     11/18/18

Good evening Bob. Thank you for your reply a few days back on the peroxide question. I’ve been dosing 1ml per 10 gallons of total water volume per your suggestion. I’ve been dosing now for about 10 days. The Cyano has been reduced by about 30%. It seems as though it’s holding and not reducing any further. I’d like to know if I can safely increase the dosage of HP to say 2ml per 10 gallons of water.
<Mmm; yes; you could. WITH careful watching that your ORP doesn't much exceed about 400 micro-siemens/cm.
I’m running ozone so I’ve been watching my ORP while dosing. The ORP drops about 80 points immediately after dosing but then climbs up to 380 within about an hour afterwards. What’s your thoughts on increasing the dosage? As always, thank you for your time.
<Cheers John. BobF>
Re: Hydrogen peroxide     11/19/18

Thank you Bob. Have a good Thanksgiving
<Thank you John. You as well. B>

Nuisance algae continued!     2/4/18
Hey Bob,
Many thanks for your reply to my original email a couple of weeks back when i asked whether you thought the brown-red algae in my tank was Cyano or diatoms. I am now pretty sure that these are diatoms caused by me
(stoooopidly!) adding reeflowers white sand to the tank as a sand filter.
I'm not sure what possessed me to do this but hey-ho, I get to kick myself everyday about it now!
<Clarity is pleasurable>
I think the outbreak is diatoms as i have done the following but to no avail.....added additional macro algae (Caulerpa & Chaetomorpha) to the sump, increased flow with 4 8000lph powerheads, done a 48hr blackout, added
2 tower filters with carbon and Rowaphos, cut down on bioload by returning 9 Chromis to lfs, reduced feeding to once very other day and algae on the days between, put more sand sifters in (sand sifting stars and conch) and
turned over the sand manually each day.
<I'd only vacuum or stir lightly once per week>

And with all this came no reward....at all! Infancy <in fact?> the algae has now spread quite stubbornly on to most of my rock work but as yet as not blanketed and corals so am happy that it is being managed at the moment. Water parameters are all spot on apart from nitrate gone from almost undetectable to about 3ppm - most likely as a consequence of stirring my sand bed!
My question really is..... (eventually I hear you cry!)......what can I do to get rid of this pest as i know it doesn't cause direct problems but it is making my pride and joy look terrible!!! Is there anything I can do biologically whether that is further reduce loading or add something that will outcompete more effectively than macro algae or will eat them, can I do anything physically or mechanically to remove as when i remove the brown sand it just regrows in a few hours........as a last resort is there anything chemically that will destroy diatoms?
<There are a few things... time going by; an RDP arrangement for culturing the macro algae in your refugium, improving ORP... via O3 use perhaps...>
I know this will now resolve the underlying issue but I am positive that this is the new silicates that I introduced with the new sand (prevention is better than cure I know!).
The problem isnt as bad as the first pics but I don't want better I would like gone!
Basically......HELP!!!!!! Ha ha
<Perhaps a (re) read here: http://www.wetwebmedia.com/algaeconMar.htm and as much review of the above links as you deem useful>
Thank you so much in advance for helping idiots like me to rectify our mistakes!!!
Regards, Martin
<No worries; happens to us all. Bob Fenner>


<Free> Live rock with green hair algae      6/2/17
Quick question,
There is a guy around me breaking down his 125 salt tank. He is basically giving away his stuff for free. He has lots of live rock that I would like, problem is there is a significant amount of green hair algae on it.
1) What would be the consequences to putting rock with GHA on it into my tank that has none
<Not much... evidence of previous lax maintenance; can be cured by improved on your part>
2) Is it safe to put the live rock he has without the algae in my tank?
<Likely so; yes. I would use it... a bargain... if naught else, cleaned/bleached/air-dried as base rock>
3) Are there ways to get rid of the algae if I were to put it in my tank?
<As stated, good care over time. A dearth of available nutrients (mainly N, P...), competitors (macro algae culture principally), and stocking of algae predators. >
Any guidance would be greatly appreciated.
<Let's have you read this review:
and the linked files at top....>

<Bob Fenner>

Algae Id     3/3/17
Hello and thanks for a wonderful site!
<We're here for you Curt>
I'm trying to get a general idea of what I'm fighting in my 90g reef tank that's a little over a year old. The attached picture shows a small sample of the brown slimy film that's on my rock and sand bed.
<Seen, experienced stuff like this ever since when. >
It doesn't seem to kill and/or attach to any of the SPS or LPS corals in the tank and is easily removed with a toothbrush but will grow back within in a few days. The only partial remedy I've found is when I soak each rock in a mix of 50/50 salt water to hydrogen peroxide for about 15 min.s. After the soak, the rock looks great for about a month or two before the growth comes back.
<Yes; conditions still favor it>

Recent tests results show 0 nitrates and phosphates,
<Being absorbed....>

Calcium=445, Alk-8.1, Mag-1440. I'm leaning towards a type of Cyano but really unsure and can't find any positive Id's on the net. Any idea what I'm up against?
<From a macro pic only can guess; this could be dinoflagellates, Cyano, a mix... need to sample and look under a low power (a few hundred time) 'scope. Send pix if you can. The usual mix of possible measures can be gone over here to combat: http://www.wetwebmedia.com/algaeconMar.htm
Am a big fan of a maximum, mixed approach: Competition, nutrient deprivation; enhanced DO and ORP... Do you have a tied in sump? An RDP refugium w/ a DEEP and large as practical DSB is a very good idea. Bob Fenner>

A Better Understanding of Phytoplankton. Control 2/24/2017
Hi Bob,
Are all species of tropical marine phytoplankton the same in terms of how one goes about getting rid of them from their display tank?
<Alike in some principal ways...>
Because I'm trying to figure out whether or not a microscope and UV sterilizer is truly necessary to eradicate it?
<There are other approaches than UV...>
So is it true that regardless of the phytoplankton species, the remedy is the same; water changes to reduce nutrients & dissolved organics along with reduced photoperiod/ intensity?
<These help generally>
And Is it possible to have dissolved organics and nutrients (I assume those are what the plankton are at least partially feeding upon) extremely low (no fish in the tank so this isn't a tall order) and yet the plankton continue to thrive solely via photosynthesis via high output LED lighting?
<Can happen; yes>
justifying the purchase of a UV sterilizer? And not needing a microscope to solve this?
<A 'scope is nice for looking/seeing small things... including algae. UVs can help both by zapping DNA of single celled life happening by, as well as by improving DO, RedOx...>
<Again; there are other approaches... Competitors, predators, filtering mechanically, selective poisoning, nutrient limitation by using chemical filtrants. Perhaps a cursory read here: http://www.wetwebmedia.com/algaeconMar.htm
Bob Fenner>

Brown Algae... New SW tank          12/6/16
Hi guys,
I've been down this road before, but just wanted your opinion with a quick question. New 60g saltwater tank, anxiously awaiting the delivery of my RO/DI unit and my protein skimmer (this week in the mail).
<These will definitely help!>
I have some brown algae starting in a two week old cycling tank. I know this is to be expected, and I know my RO/DI water, regular water changes, and introducing a protein skimmer will wipe this out in a few weeks. My question... if Nitrates, Nitrites, Ammonia are all in check at zero... is it appropriate to introduce a clean-up crew during this brown algae bloom?
<Mmm; I'd wait a few more weeks myself. For me, the undue stress on this life is just not worth it>
Is it harmful to hermit crabs, snails, maybe a banded or brittle starfish?
<Yes; harmful>
My plan while battling the bloom... intro the cleanup crew this weekend, and if water parameters are still in check, then introduce two clowns and maybe a watchman goby in two weeks.
<I urge patience. So easy to key eh? Bob Fenner>

Help with Anemone and Algae. Moved sm. sys., cascade event      7/1/16
<Eight megs... is there a full moon? Why are folks sending such huge files?>
Hi there. I need help...About 1.5 months ago I moved to from San Francisco to Monterey for a job, and moved my 24 gallon reef tank for the second time in 2 years. My tank has been established since Oct. 2013, and has been thriving up until this move.
During move I followed the same protocols I used when moving two years ago (which was successful), which were the following: Placed biggest piece of live rock in bucket with airstone and heater along with all non-coral animals. Placed all other live rock and corals in a Styrofoam cooler in water. Emptied tank nearly all of the way, leaving 1/4" of water above the live-sand. I was able to plug heater and airstone into electricity with adapter in my truck. Drive 2 hrs, set up tank, all seemed fine until 2 weeks later...
Fast forward two weeks and I started to get brown slimy/hairy algae on sand, rocks, back walls etc.
<I see this... likely a release of nutrient/s... loss of RedOx/ORP... alkaline reserve in your substrate
I would siphon out as much as I could during water changes, revealing nice white sand under the brown scum, but it
comes back after a few days. At the time of my move I also switched to Reef Crystals from Instant Ocean for salt mix, and also purchased an under-sink RO system. Where it got weird is when my normally super-happy bubble tip anemone spawned, probably 1 month into the move. A big blob of eggs were released from her (I guess it is a she) mouth. I netted as many of them as I could. Ever since that spawn-night, the anemone has been small, deflated and wandering. It slides from one spot to another night after night, and never inflates to its previous 8-10" size. I realize that I might have
stirred up gunk in my 2-3 year old live sand during move,
but wouldn't I see a noticeable uptick in nitrates? The tap water here smells very chlorine-y also, but shouldn't my RO system be filtering bad stuff out?
<It should... and you likely have a carbon contactor pre-filter. You could test for free chlorine...>
My underlying question is; what could be simultaneously causing this algae outbreak and also stressing the anemone?
<The gunk stirred up in your old substrate; subsequent allelopathy with your other Cnidarians...>
Are there additional tests I can run to find out?
<Sure; HPO4, NO3, K....>

Here are some details about my tank: As mentioned 24 gallons, all-in-one setup with Tunze 9002 protein skimmer, heater, power head, and bag of MarineLand activated carbon dropped in back chamber every couple months.
Livestock: percula clown, royal gramma, Longnose Hawkfish, Banggai cardinal. A couple hermits, a couple turban snails, 1 fighting conch, 1 tuxedo urchin, 1 skunk cleaner shrimp. Soft corals (Christmas tree, various mushrooms, Zoas, leather), a few LPS (plate coral, hammer, torch, war coral).
Levels: Nitrates, ammonia, nitrites all "0"
<Really? NO NO3? I'd check with another kit
, pH 8.1, temp 78. I can measure for calcium and dKH but generally don't. I used to dose iron but don't anymore.
<I would, and iodide-ate... I might skip ahead and dump the entire existing substrate and replace first>
I have attached pictures of the algae (I think it is either dinoflagellates or cyanobacteria),
<Likely... need a 'scope look and see>
and am desperate for a concrete way to put a stop to it.
I have also attached a picture of the anemone spawn, and anem pics before and after move. Let me know if you need additional info to assess the problem.
Thanks in advance for your attention on this.
<Try searching, reading on WWM re these algae groups control. Bob Fenner>


Re: Help with Anemone and Algae      7/1/16
Apologies. I thought the pics were small enough, thanks for responding anyway. I will replace my sandbed...are you able to make a recommendation on live sand?
the linked files at top>

And yes, I have tested "0" Nitrate for the past year and a half...I just figured my bioload was low enough or that I had a super effective bio filter. I will get a new kit.
Thanks again.

Alge... rdg.       4/23/16
Hi my name is jonas martin I have a 55 gallon salt water tank. And I have an out break of brown algae.
I have sufficient flow in the tank. And a canister filter capable of handling that size aquarium. Is there any way I can eliminate the brown algae. I only have two blue damsels and one Condylactis anemone. How can I fix this issue.
<Read here: http://www.wetwebmedia.com/algaeconMar.htm
and the linked files above. Bob Fenner>

Marine aquarium algae control book      4/22/16
Hi Mr. Bob, I just wanted to let you know I picked up the above book written by you. I have been battling a very frustrating algae problem. But from the links here and the book, I am slowly getting it under control. I still have
a ways to go but know I will get bit fixed. Thank you for all of the advice you have given us all , and of course thank you to the rest of the crew.
For anyone battling nuisance algae, I recommend the book and the advice archived here. Have a great day! Stace
<Thanks Stace; you too. BobF>

Marine fix opinion.... Not a reader. Go elsewhere       4/3/16
Good afternoon,
What is your opinion on the API algae fix.
<A very poor idea to use most chemical algicides... as gone... Oh, good riddance. >

I am currently letting my tank
run fallow, feeding one cube of food per week for coral and live rock, and
have quite a bit of hair algae on the rocks.
I was told this is a biocide that will help destroy the gha. I am
running gfo, skimmer and carbon, and only feeding once a week.
Since I will be going fallow another 6 weeks or so, one part of me says
it run its course, and not feed, there half of me says to continue feeding
the coral once a week and give this product a try.

Red Algae; using WWM        2/18/16
Hello gang. Is there some secret to getting rid of red algae?
<Saltwater, fresh? No to secrets; but yes to means
I've had a 150 gallon tank for years now and can't seem to kick it. Fish in it are happy and fat and have been in it for years. A powder blue tang, blue ring angel, Stars and Stripes puffer and lemon peel angel. Filter is 55 gallon Wet dry sump with bubble magus cone skimmer. Water parameters have been tested many times and are always where they need to be. Nitrates at less than 5-10 ppm, ph stable and in range. Red algae covers most things but isn't "hairy".
<.... need a 'scope, sampling to determine what Division (group) this algae belongs to... Is it slimy to the touch?
There is some green mixed in here and there. Added some powerheads a year or so ago to increase water flow. That helped some, but red is still pretty prominent. Not sure what I am missing here.
<.... Reading.... re nutrient deprivation methods, predators, competitors... The usual
Tank is pretty much problem free otherwise. One thing I've noticed lately, which I found odd and wouldn't have expected, is if I go longer between pulling the filter bags out and cleaning them the green algae starts to spread or red starts to lessen, not sure which. Any thoughts on this would be a huge help. Thanks in advance!
<Where should I refer you? Start reading here:
and onto the linked files as you lead yourself.
Bob Fenner>

algae control      1/25/16
HI there! Exhausted my search and have finally decided to write. I have a IM Mini 40 that has been up and running since February 2015. Equipment includes a Tunze 9002 skimmer, two Jebao RW-4 wavemakers, and an IM Minimax media reactor midsize that I am currently running with AquaMaxx GFO Phosphate Out Granular Ferrous Oxide Filter Media. Lighting is a Maxxspect Razor set on a dusk to dawn cycle settings:
01:30 1B 0W
04:30 0B 0W
09:00 0B 0W
12:00 60B 100W
21:00 60B 100W
23:00 60B 0W
Tank stats are as follows: Salinity 1.024 Temp 76 degrees now, but in summer will usually run around 78 degrees, PH 8.0, Ammonia 0 Nitrites 0 Nitrates 0 Phosphates 0
<Mmm; your chemo-photosynthetic life absolutely needs soluble N, P, K...
you need to understand this. You will not be able to keep "corals" long term sans nutrient
Calcium 420ppm Alk 12. I have 4 H Reidi seahorses in the tank, a leather coral a chili coral, various mushrooms, metallic green star polyps, glove polyps, red/green Blastomussa polyps, Duncan coral, a Dendrophyllia frag, a Muriceopsis flavida(I think), blue Sympodium, another small star polyp around 6 dwarf red legged hermits and an assortment of Trochus, Cerith, Nerite and Nassarius snails, all of whom do a great job keeping the glass clean but none seem particularly interested in the algae growing on the rocks.
<There are many thousands of species... a minority of which are palatable to these Gastropods and Anomurans>
I had originally attempted to convert one of the back chambers of the tank into a refugium using the Aquagadget custom caddy and the IM fuge light
<Ah, good. THIS is your best shot, modality for success period here. IF there's room, find a spot for a sump/refugium elsewhere to tie in (plumb)... W/ a DSB, RDP lighting... as gone over and over on WWM>
but to date have been unsuccessful in keeping any kind of macro algae alive in there.
<Not surprising... there's insufficient food...>

That is my first problem. I can't figure out whether the light is too strong too close to the algae, do I have it on for too many hours?
<Would need to know the species tried, measures of at least PAR/PUR....>
(I was trying to reverse the lighting cycle from the main tank) I did reduce the fuge lighting to on for around 4 hours, but I still can't seem to grow the macro back there, so I gave up.
Problem two - I believe started when I purchased some macro algae for the fuge. It never occurred to me to quarantine the macro algae (stupid, I know now) but lesson learned the super hard way since I believe I became infested with red Planaria as a result. The macro algae was the only new thing. Anyway, I spent the last four months battling this monster, siphoning them out, water changes and finally Flatwork eXit x three times. Just as an FYI, it still didn't work 100% and I ultimately ended up siphoning the bulk of my sandbed out because that seemed to be where they were living. I have beaten them now (I hope) but at the expense of several of my corals. Despite my best efforts to siphon, do water changes after treatment, etc this whole process wreaked havoc with my water parameters, causing just general everything all over the place (ph down nitrates skyrocketed, ammonia stayed 0, phosphates high, calc and alk dropped - just a general disaster) This began my algae problem. It was at this point that I added the media reactor with the GFO and got the water parameters to what they are now (listed above).
<But no added substrate? I would>
However, I can not seem to get rid of the algae. I believe it is the B. Plumosa. It would be extremely difficult to remove the rock since I have corals attached to it. I have tried to scrub it off with a toothbrush to no avail and it has taken hold between some of the polyp frags I have in there and I can't get in between the individual polyps. I am frustrated beyond belief at this
point and am desperate for help. I read that increasing magnesium levels may kill it off, and I just purchased a magnesium test kit to monitor the magnesium level. Just tested a couple of days ago and found Mag level to only be 930, which is low anyway. I have been adding magnesium to the tank a little bit at a time to try and raise it to correct levels. Can this be why the algae is still growing, and will increasing the levels work with this type of algae?
<Maybe. I'd be considering the above approach I've mentioned>
Sorry for the long email but wanted to be as thorough as possible with what's been happening. Any suggestions would be welcome along with a reminder about why I got into this hobby in the first place lol.
Regards, Liana
<First of all; don't give up! There are quite a few approaches to try... IS there room... nearby for the tied-in sump/'fuge?
THIS is the route I would def. go with. Bob Fenner>
Re: algae control      1/25/16

Sorry, yes did replace the substrate with about an inch of pink coral sand.....
and the Planaria are not beat as evidenced by my spotting several just moments ago
- hadn't really seen any for a couple of weeks now - there are just a few. My next move was to add a refugium below the tank only room for a small one but still not sure how that will help rid the algae since phosphates and nitrates levels good.
<Will help in myriad ways... again, please search WWM, read books I've penned re... And you HPO4 and NO3 are NOT good... See WWM re this/these as well.>

Pics of tank below if that helps. Thanks Bob - you and the crew are an amazing resource!
<Glad to assist your efforts. Oh! Pix not attached. BobF>
Re: algae control

Ah yes I see that missed comment re the water parameters - looks like I have much water chemistry reading to do -
<Not too much>
I feel very dumb right now. (sigh).
<Feel empowered~!>
Thanks again and read I shall. Liana
<The subjunctive case; wow! Bob>
Liana tank      1/25/16

<Very nice. B>

Liana tank algae      1/25/16
<Not so bad.... B>

Algae  (!?)
I am new to Saltwater tanks and I am having problems with algae. What can I do to control this?
<Perhaps start by reading...
Lots of useful information there to get you started. Cheers, Neale.>

Mysterious algae or bacterial film. Please help!         12/4/15
<.... six Megs of pix. What and why do we limit file size?>
Hello! I am currently battling a strange film in my tank.
<Mmm; nah. Do you have a microscope? Can (will) you learn to/use WWM? >
At first, I thought it was cyanobacteria, but the normal methods
<Which are?>
of eliminating that haven't proven to be useful. Reduction of lights, increased flow, more/larger water changes, new/increased GAC and GFO,
<Try PolyFilter or its equivalent>
reducing feeding, and even products like Chemiclean
<A poor idea>
haven't made as much as a dent in it. Then I began to think it might be dinoflagellates. I had an episode with them
before, and I was able to get rid of them by using a multi-pronged approach of blackouts, hydrogen peroxide, a uv sterilizer, and DinoX.
<.... There's an endogenous source of nutrients here... either the rock or substrate is feeding... Try boiling a sample... testing the water>
This stuff, however, also doesn't respond to any of those things, either. It also doesn't have the appearance that the previous dinoflagellates had. It doesn't create streamers of bubbles, and the texture isn't "snotty" like the Dinos were. I am really at a loss here, and I would like to make a positive ID,
<The 'scope; reading on WWM, maybe my book on Algae (see Amazon, Bookfinder....)>
figure out why they've gotten so established in the first place, and come up with a treatment plan. I appreciate any light that you can shed on this matter!
<Have seen a 'zillion times as the saying goes.... the N, P, K source here? hard material/s you've placed.... or much less likely the water, salt mix>
<Read on! Bob Fenner>

Mmm; plus Myrionema?

Re: Mysterious algae or bacterial film. Please help!      12/5/15
Thanks for the response. I was mainly looking for an ID, and I mentioned the treatments, etc, to explain why I'm unsure what it is.
<And I responded that the only means to tell for sure was what? And what the likely sources of nutrient? TRY using WWM. B>
Re: Mysterious algae or bacterial film. Please help! /Earl?       12/5/15

Why do you think that I didn't try that first? I did, and I wasn't any more sure. After trying, I thought I'd ask the experts. But it seems like you were just annoyed. I'm sorry if I bothered you.
<A detailed listing of your water parameters, whatever you can test for, would be of a lot of use. There are a *lot* of faq's and pages of info about these nuisance/pest algae and bacteria etc. on the site here but we can't do a lot without more detailed, specific information. Your source water maybe, readings as per above, inhabitants, what kind of feeding you
do and of what. Also please note the file size limit we have to work with. Detail and close-up resolution is great but practical/functionality considerations are a reality. I recommend simply using image editing software (surely you use some for your camera...if not you can use GIMP which is good freeware). Maybe home in on demonstrative areas of the photos, crop them smaller to focus there, and be sure to "save for web" as a 72dpi file.>
Re: Mysterious algae or bacterial film. Please help!    /back to RMF       12/5/15

Why do you think that I didn't try that first?
<Because if you had you wouldn't have written>
I did, and I wasn't any more sure. After trying, I thought I'd ask the experts. But it seems like you were just annoyed. I'm sorry if I bothered you.
<Not a bother.... are you a non-native speaker/reader? Do you know what I've referred to as a "microscope"?
That this is the only way (apparent color won't do it alone).... DO please
re-read some of the articles and corresponding FAQs files on Algae Control on WWM; and write w/ specific questions. Bob Fenner>
Re: Mysterious algae or bacterial film. Please help!....         12/6/15

Is there a minimal magnification that you would recommend for help in identifying type/species?
<Yes.... 200-400X will do it....READ here:
It wouldn't be money well spent for me to buy a research-grade microscope if I only need it occasionally.
<Nah; a very simple QL series... do just read. About 30k people use WWM per day.... not able to re-key all>
Unfortunately, I don't currently have access to a microscope, which was why I asked for helping with an ID.
<Ask about at your local fish stores. Likely someone has one that they'll let you bring a sample in and use>
I'm sorry if I wasn't specific enough with that question. I received your other email about providing specific parameters, and I am currently doing tests to get these numbers. I should be sending that shortly.
<Ah good.... and that wasn't from/me... or signed... another WWM Crewmember, perhaps Earl. BobF>
Re: Mysterious algae or bacterial film. Please help!

Ah, I see. Thanks for the specifics.
Water parameters:
- SG 1.026
- hw-Marinemix reefer salt
- RO/DI (via SpectraPure unit) water
- TDS meter shows 0ppm
- Always replace DI resin when TDS shows 1ppm.
- pH 8.1, according to calibrated Milwaukee pH600
According to API test kits:
- Ammonia: 0
- Nitrite: 0
- Nitrate: 0
<Mmm; how is NO3 rendered zip?>
According to Salifert:
- Calcium: 390 - 400
- Magnesium: ~1170
- Alkalinity: 8.6dKH
After testing, I added a dose of Kent Tech M to get my Mag level closer to NSW.
According to Hanna Checker colorimeter:
- Phosphates: 0ppm (Do I need the higher sensitivity (ppb) checker?)
<No; assuredly not>
With a bloom, I'm not surprised that NO3 and PO4 are not detectable.
<Yes; possibly the mix of Protists, Monerans here is "sucking up" most all simple chem. nutrient>
Tank inhabitants:
- 2 percula clownfish
- 1 Cerith snail
- 1 red-leg hermit
- 1 colony of Zoanthids
The rest of the snails and hermits died during my dino outbreak 6 months ago. Waiting for stability (and necessity) before any sort of scavenger re-stocking.
Feeding regimen:
Formula 1 pellets, small amount (~10 small pellets) each day or every other day. I feed only a few pellets at a time to ensure that they are all eaten.
I'll send you links to better pictures to ensure that the attachments
aren't blocked for size, and so that you can see the entirety of the pics:
Thanks again,
<Mmm; well; there are a few "routes" you could/might go... for me.... I'd remove the useful biota, nuke/bleach the system and components (in place, including the rock, gravel).... ADD a large refugium, w/ a DSB there, on RDP lighting regimen.... and add a few lb.s of new live rock to restart; put the biota back in.... Bob Fenner>

Hair algae-Second send, smaller pics      7/8/15
I'm going to apologize in advance for the length of the email, but I did want to make sure I gave you every detail possible.
<Real good>
I have been combating hair algae for approximately a year now.
<No fun!>
Here is the current stock and tank information.
180 gallon reef tank 72in x 24in x 24in, 80 lbs live rock, aragonite substrate
<Mmm; well... let me comment as we go along. I'd ditch the Aragonite... see WWM for rationale and alternatives>
30 gallon sump
<Oh! What do you do with this sump? I WOULD have a DSB here, RDP macro-algal culture>

Livestock, inverts, corals: 2 black and white clowns, 2 ocellaris clowns, mandarin dragonet, royal gramma, orchid dotty back, lawnmower blenny, azure damsel, 5-pincushion sea urchins, purple Linckia starfish, peppermint shrimp, handful shrimp and snails
Zoas, Palys, hammer/anchor, star polyps, mushrooms, Sympodium, candy cane, rock anemone, rose bubble tip anemone, Acan (not doing so well)
<Likely it's losing to the Zoanthids and more... Better placed elsewhere>
Livestock fed about once a week-
<I'd increase this with smaller feedings to at least every other day... if not daily>
frozen and freeze dried mysis, salmon roe(Asian market sushi), new life spectrum. Stopped frozen stuff about 3 weeks ago after realizing the perils of not washing
Coralife 2900 powerhead installed a couple weeks ago (prior to this Koralia 1400)
Hydro Koralia 1500
Kessil 360w x 2
one cheap recycled LED with just the actinic being used
Reef Octopus Classic NWB 110 in sump skimmer(I know this is under rated for the size of the tank, clean out grime weekly)
Homemade phosphate reactor using PhosGuard introduced about 2 weeks ago(prior to this phosphate was at 1.0)
Auto top off with unsalted RODI water
5 stage BRS RODI with chloramine for source water; filters changed about 2.5 months ago, but prior to that had not been changed in a while(well passed what they should have been).
Seems like problems with algae started shortly after a major tank wipeout from ich.
<Am wondering what your RedOx is here... I'd bet low; under 200 uS/cm.>

Left tank essentially fallow(no fish or coral) for about 3 months or so.
Started reintroducing fish and coral shortly after algae started. Measures taken-removed all substrate(typical sand) and switched to aragonite and rocks scrubbed about 3 months ago. Tank looked good for about 1-2 weeks
and then algae returned. I've bulb suctioned and manually removed the algae with water changes. Water changes about 10-20% every week. Current levels as of two days ago with water change were
kH 5.7
<Mmm; low... s/b 7-9.... the higher value better>
alk 2.05
<Better higher.... I'd shoot for 4 meq/l>

Nitrates 0.2
Phosphate 0.25
Calcium 500
<Too high... I'd keep under 400 ppm>

Mg 1410
<And this in proportion... about 3X>
pH 8.2-8.4
RODI water nitrates and phosphates negative
<The above two mighty fine>
I've included some pics, taken two days after a water change
<Bunk and gunk!>

Again, apologies for the lengthy email. Thank you so much for your help
<No worries... you see my suggestions above? Dump the gravel, mod the sump/refugium (add sugar fine DSB of 10 cm/4in plus depth), macro-algae of use; lighting on a reverse photoperiod....); increase the feeding interval;
time going by.... and Wham! All fixed. Bob Fenner>
Re: Hair algae-Second send, smaller pics      7/8/15

Bob thank you for your quick response and expertise. After your response I tried to find all the articles about the RedOx and dsb/macroalgae use so I didn't ask a bunch of already answered questions,
apologies if I didn't succeed. I'll decrease calcium and magnesium, increase alk/kH. Would you actually recommend measuring RedOx level or just treating empirically by adding Caulerpa?
<Am a HUGE fan of measure; and if practical, manipulation (w/ 03 admin.) of RedOx... ALL public aquariums and bigger wholesale; many retail facilities avail themselves of this useful tool/window into biological fitness of systems>
I'm running into a little bit of confusion regarding the substrate. From what I am reading(please correct me if I'm wrong) the issue is more with the size of aragonite and not the aragonite itself.
<You are correct; though many "aragonites" trend to be more calcite/insoluble than useful period>
I will add a sugar fine dsb into a section of the sump along with macroalgae. Is your preference Caulerpa or a variety?
<Please read here re: http://wetwebmedia.com/refugalgfaq2.htm
Am decidedly against the use of Caulerpaceans nowayears; instead push species of the genera Gracilaria and Chaetomorpha>
Whatever the substrate is would you recommend the display tank have sugar fine as well?
<Mmm; yes; unless you're stocking some organisms that can/will use other... >
So after correcting all of this will all the algae dying off cause a spike in nutrients and if so will normal water changes be sufficient or will manual extraction be needed?
<Indeed it will>
Thanks again for all the help
<Thank you for your intelligent, patient involvement. BobF>

Re: Hair algae-Second send, smaller pics        7/9/15
Okay I'm eyeballing the Milwaukee ORP tester on bulk reef. As far as treating with ozone, are the human health concerns reasonable and likely
<No.... as gone over and over... on WWM, books and articles I've penned... get/use a unit (ozonizer, likely a corona discharge unit) that only produces a few mg. of 03 per hour... No human danger>
(have a 13, 8 and 3 year old)? I went ahead and got some Chaeto and Gracilaria from LFS and put it in sump with LED lighting. They had CaribSea aragonite Aragamax sugar size oolite-would this be acceptable?
<Ah yes>
Thanks again for your advice
<Welcome. BobF>

Marine aquarium... no data; reading, using WWM       7/8/15
Hey my name is Michael I have an aquarium that is over run with green hair algae what do you recommend.

I've tried everything pulling and brushing it off. Shortened my lighting introduced a few fish recommended from local pet store and nothing it always comes back I'm using water out of a ro system for water changes my pH levels seem good in my water test. Any help would be greatly appreciated. Email me backache XXXX@yahoo.com thanks
<Uhh; start here: http://wetwebmedia.com/marine/maintenance/maintindex.htm
scroll down to the algae tray.... general and hair algae FAQs files... Bob Fenner...>

algae? Dinos? bacteria? alien life form?      7/8/15
Dear WWM crew,
Your site has been a huge help to me in setting up my saltwater aquarium in land-locked Saskatchewan!
I'm currently having a problem that I can't quite identify. I've searched wwm pretty thoroughly but without a definite id I'm unsure how to proceed. There's something growing on one pane of my aquarium glass. It started 3 weeks ago. It's spreading quickly though! It's very gelatinous and clear, frondy at the ends, but seems to grow from a brownish pin sized circle attached to the glass. The fronds disintegrate when scraped or suctioned, the circles require some scraping to remove.
<I do so like these mysteries! Could be.... algal; perhaps a Ctenophore/comb jelly, or a Hydropolyp of some sort, or...
Any chance of a high-res. photo? Do you have a USB-ready microscope (like the Intel-Mattel ones plugged on WWM?)>
It doesn't produce bubbles and the fronds are thicker than the pictures of Dinos I've seen. It comes back 2 days after I scrape/siphon it out. I put a filter on the system whenever trying to clean it. The reason I'm concerned is that as soon as it started, I started losing my Astrea snails.
<Ah, all good clues>
They are now all dead. I suspect it took out the tiny snails that came in on a frag too, I haven't seen them. Nothing else is currently affected, in fact the pods seem to like hanging out in the stuff, but I really don't want this toxic whatever it is to spread! I have the typical red Cyano.
<Bunk; and dangerous at times. This along could account for your snail losses>
I've only started to see green nuisance algae last week, in one spot on my rock. Ideally you'd wave your magic wand and make this stuff go *poof* but if it's on the recharger, I'd really appreciate a more definite identification. I'm hesitant to go crazy against algae if it's bacteria and vice versa. I hope it isn't Dinos.
<They are not the "end of the world" (have seen it/this and they're not there)>
What I've been doing to manage it: manual removal every 4 days, 20% water changes after scraping, running filter cloth on return, activated carbon in sump. Cut down feeding (mix of tiny amounts tiny frozen mysis, oyster eggs and oyster ovarian tissue, new life teeny pellets mixed with tank water. I use a 5ml dropper to feed and fill it maybe half full.) I haven't added
any supplements except alk/calcium- tailored aquatics is the brand name.
Nutrients have always been low in this tank, I only added the goby a month or so ago. Pre fish I put in 5 or so nls pellets a day to give the worms/pods something to eat. I notice an odd smell from the change water.
Not rotting or sulphur, ocean-like or that soft-coral reek, but sharp.
(Does Chaeto smell?)
<Do we smell them you mean I'll take it: sometimes>
Tank info:
JBJ 28g gallon all in one. Stock lighting-compact fluorescents, 105 watts, half actinic half white, on for 7 hours a day. (Have ordered a new bulb, waiting for it to be delivered)
<I'd sub another "white" of use for the actinic m'self>
No skimmer. (Worried about stripping already low nutrients in tank) Usually do Weekly 10% water changes, bumped up to
20% every couple of days for the last few weeks. Been running for 5 months.
Chemistry: Temp 78F, Salinity 1.025, Alk 8.2, no ammonia, nitrite, nitrates >5 (tough to read kit),Ca 450, phosphates 0.03. Waiting for Mg test. I add alk supplement about every 10 days. Running small amounts activated carbon.
Nutrients have been very low since the cycle. Started with dry rock and dry sand due to unavailability of live stuff.
Livestock: Yellow clown goby.2 sexy shrimp, brittle star I haven't seen in a few weeks and hope is ok, hermit crab added a week ago. 5 very tiny Euphyllia frags, Discosoma mushrooms, 1 toadstool,
<Yikes; Sarcophytons can get very large and quite toxic>
1 Ricordea. Lots of copepods- they are all over the suspect goo. One of my shrimp hangs out on it also. Ball of Chaetomorpha algae which hasn't been thrilled with all the water changes.
Relevant tank history: 6 weeks ago a period of wild alk swings ended. It lasted 3 weeks, alk would drop 3+ dKH a day. This tank has been weird for not getting green algae. Lots of brown stuff (diatoms probably) but no green. I take out half the ball of Chaeto monthly. Coralline was starting to grow but has stopped and is vanishing since this goo started.
<Mmm; more poss. clues.... You need to stabilize water quality... if needed through larger, more frequent water changes; the new water bolstered through supplementation if needed>
http://s1164.photobucket.com/user/Quiet_Ivy/media/28g%20Reef%20Tank/sunday%20tank%20001_zpsj3bvygwl.jpg.html (close up)<Oh.... this does look like a Dinoflagellate mess... I'd have you read re these on WWM; and...>
http://s1164.photobucket.com/user/Quiet_Ivy/media/28g%20Reef%20Tank/gunk2_zpsnsxhpop1.jpg.html when allowed to grow undisturbed for a week
http://s1164.photobucket.com/user/Quiet_Ivy/media/28g%20Reef%20Tank/full%20tank%20shot%20june_zpsqycrqixe.jpg.html  (full tank shot, early June. The suspect goo is on the left side panel, near the sand. I believe this is day 2 since removing it. Have moved frags around since but added only 1 Ricordea)
Thanks very much for your wonderful site and sorry about the length of this,
Ivy in Canada
<No worries; and the mention of a new "algae" manipulating product, "Nualgi"; a promoter of diatoms; that deprives other, noisome algae of nutrients.... have met w/ the owner/distributor; and though it works almost always in ponds, and off/on in aquariums (mainly dependent on their make up bio/chemically); I would try this out here. Bob Fenner>

Green Hair Algae; SW, control, more rdg.       2/3/15
Hi WWM crew,
First, I want to mention that I did search your site as best I could to find the solution before resorting to emailing. The topics I
found covered things I have been trying for some time now, so felt it prudent to email you.
I've got a 55 gal saltwater tank with a 10 gal filter tank below.
The tank below has a Remora skimmer, standard 100 micron filter sock, heater, phosphate reactor using PhosBan product.
<Mmm; why?>

I've been battling green hair algae for 6 months now. It’s covering about 60% of my live rock. I need to prune it by hand at least every month to keep corals from being covered.
i know this is due to an imbalance with nutrients.
<Mmm; no; not necessarily... could be lack of predation, competition, too much or wrong type of light... quite a few other important factors>

I feed minimally and slowly, ensuring the food is mostly eaten within 1 min, once per day (in an effort to cut down on nutrient overflow.) I also feed 1 algae wafer per day for the tang and other herbivores. my stock is 2 clowns, 1 cole tang, 1 cleaner shrimp, 3 turbo snail, 1 flame angel, 1 Chromis, 1 file fish and about a dozen small hermit crabs.
Lighting is about 10 hours a day. Comprised of 4 x 48 inch T5 lights... (2 actinic and 2 white.)
<I'd ditch the actinics... See WWM re>

I use 3 powerheads in the main tank for circulation. Also in use is a uv filter.
Please let me know what you suggest.
<More or re-reading re general algae control. Start here: http://wetwebmedia.com/algaeconMar.htm
and the linked files above. Don't know why you, others throw your money away on "controlling" HPO4... The media here are likely a good source of the "imbalance" issue you mention.>
Thank you
<Read on! Bob Fenner>

what is it and how do I make it GO AWAY     10/23/14
Hi Guys,
<Nan; eight megs of pix? Why?>
It has been awhile since I contacted you, which is a good thing:) I have downsized from the 180gal to a 75 gal and I can now reach the bottom without swimming. I have the large sized ECO filter, a small protein
skimmer, deionized make up water. Livestock is mostly soft corals and a few fish, a large tang, large engineer goby and perhaps 10 small 1.5 - 2' other fish. Oh , and the big Ritteri anemone :).
The red slime algae comes and goes with the season but is never a major issue. I have developed this green stuff on my stony coral though.
<Mmm; looks like Cyanobacteria as well... the color is not indicative... Need to look at a bit under a low power microscope>
There has been a small patch of what I would call fuzzy green algae on one rock for years. It stayed there and I ignored it. Awhile back I noticed a small patch on the coral so I put some 'Aiptasia out' on it. Needless to say it did nothing. So I had a bit of Super Glue left from a job and covered the whole spot over with it. It came back with a vendetta and as you can see, is taking over my coral who will not even spread it's polyps
any more.
I did not see anything on your site that covered algae annihilation. Have you any suggestions?
<The usual reading on WWM. There's a few approaches... that work, and some that should be avoided (use of antibiotics)>
thanks, Nancy D
yes, those 2 pictures are the same but I can't seem to get rid on one:)
I didn't see anything on your site that covered algae annihilation. Have you any suggestions [image: Inline image 2][image: Inline image 1]
<The reading. Bob Fenner>

Re: what is it and how do I make it GO AWAY     10/24/14
Under magnification will the Cyanobacteria look like a bunch of vibrating rice?
<Vibrating? As in moving? This is artifactual... Cyanobacteria are photosynthetic Monerans... look like bacteria... no nucleus, a single strand or twisted DNA; peculiar single-walled plasma membrane. See WWM re>
I did see some of that many years ago but tend forget to use the microscope. I will check out that topic and see what pops up.
Thanks, N
I have to laugh at me--- I can save a life but I am technologically challenged!
<Want to start a club?>
I seldom watch TV cause there are too many remotes to deal with.
<I can barely use my cell phone... even just the phone functions... I taught H.S. physics (and chem. bio. courses); can't wire a circuit. Your turn. Bob Fenner>

Re: what is it and how do I make it GO AWAY     10/26/14
OK Bob. So I got on your site to look up cyanobacteria. You question my 8 megs of pictures but you have 10,000 pages for me to search through?
Are you sure you didn't use to write Congressional proposals :)
<Or a brief work on understanding women?>
I did read an article and yes, I do get a bit sloppy with my reef in the summer. As much as I hate to admit it I probably caused the effect:(
Haven't borrowed the microscope yet but did get furring strips over the board joints so my birds won't freeze. Winter is on it's way!!!
<Brrrrrr! BobF>
Re: what is it and how do I make it GO AWAY      10/30/14

I borrowed my grand daughter's cheap-o microscope (cause no one could find the good one) and the dab of stuff I scraped off the coral appeared to be tubular with strings running lengthwise.
<Did these string have nuclei?>

I gave the coral a leisurely bath in Red Slime Remover then put it in time out. I suspended it upside down in the back of the tank. Since the stuff is green I will consider it to be photosynthetic and I am going to shut
down it's power source. I suppose the worst I can do is kill the coral and at least it will not be a slow painful death as it is invaded by 'whatever'.
Re: what is it and how do I make it GO AWAY      10/31/14

they appeared to be segmented but I really could not say I saw nuclei.
there was a couple larger circular critters which obviously did.
<Keep reading!>

Bad encrusting algae      7/17/14
I am not sure if anyone is at this site anymore.
I have some questions concerning some algae that was diagnosed by Bob Fenner as "Peyssonnelia".
I have a similar looking algae as the person on your site does here, http://www.wetwebmedia.com/redalgcompfaqs.htm on 8/22/07
I have considered Dinoflagellates as a possibility, however I am not all together sure.
<This is a mix of a few Divisions of Thallophytes, plus Cyanobacteria...>

Either way here are the things I know about;
It's first sign of existence is the whiting out and dying off of coraline algae. Then you will start noticing dead snails around the tank as they eat the algae and it kills them. Then all other algae in the system dies off as this algae will out-compete even Chaeto. It is dark brown at its base and is very filamentous from its base up. It is hairy yet it encrusts.
The hair on it in one of my systems is easily 1/2 inch long. I have tried killing it with a saltwater/2(HO) mix and that doesn't even kill it. The ONLY way I have found to kill this algae is through lack of light over
many days, an by many I mean almost 14 days. I have attached some pictures.
<Take the long read on WWM re marine algae control period. Bob Fenner>

Re: Bad encrusting algae      7/17/14
I took the long read and came up with nothing that would help with this.
<.... tis the same ole approaches: Nutrient deprivation, competition, predation.... chemical filtrants/improved skimming/higher RedOx....>

I have tried many different techniques and most of them did not work. I am not sure if either Thallophytes or Cyano is correct as neither of these match the description of the algae.
<... have to look at under a 'scope. Easy to see the various parts of this mess thereby>

I have seen quite a few other with the same problem as I have and no one has yet to be able to correctly ID this algae.
<..... my friend. Go back and READ. BobF>

I personally have written about it many different places and no one has been able to ID it yet for me, or help me with getting rid of it. The only thing I can say for sure that kills it, is lack of direct light for a period of time; at least 2 weeks.

Re: Bad encrusting algae....       7/18/14
Okay, I'll go back and read it again.
<Let's have you start here: http://wetwebmedia.com/avoidingalgaeproblesm.htm
and onto the linked files where you consider more info. will be useful>
I am trying to out-compete with Chaeto under high intensity lighting as well as nutrient deprivation. I
am not going to lie, the two clowns, yellow tang, and blue damsel were quite skinny before all of this. How much should I starve the tank?
<"Keep reading....!" B>

Algae... just reading as usual     6/11/14
Can anyone one aquarium be so unlucky as to have : hair algae, Bryopsis, green bubble algae, Gelidium, Cladophoropsis.
I have 0 phosphates and nitrates.. Running skimmer heavily, put a fresh batch of gfo and carbon. Along with water changes. I don't feed heavily, or have a heavy bio load. I'm not sure what else to do. Please help.
Thanks in advance for any tips.
<Uhh, predators, competition, nutrient limitation, export... READ here:
and the linked files... Bob Fenner>

Hairy algae        4/9/12
<Just search WWM re. Bob Fenner>

Hi my name is bradley I have had my marine aquarium set up for a year and a
half now but keep haveing trouble with green hairy algae I start getting
controll of it but it just comes back . I do 10 percent water change every
week have nitra bio cubes in the sump . I have about 50 snails and 5 crabs
so a good size clean up crew for a 2 foot tank . If you could help me with
some advise it would be grate thank you

erythromycin as last resort? Risky?      1/19/14
Hello Crew! I so need some concrete advice, as there is too much to sort through on this subject and I want to know what YOU would do!
<Will do Pam>
I'm about to dose my reef tank with erythromycin.
I've been battling Dinos for four months, and have done everything, from 5 day blackouts, to keeping the pH high (8.5), to no feeding and taking out the fuge that contained Miracle Mud,
Also, NO water changes for a month(Julian Sprung),  to siphoning and scrubbing , to melting down on Facebook, nothing has worked!
<"Running a large country is like cooking a small fish">
The Dinos have subsided, I'd say quite a bit , but in the last week, they seem to be on the move again. I must mention, I also have some sort of algae on the rock that hasn't budged at all.
I've had the advice of many knowledgeable people (ones YOU know !) and I fear that erythromycin is my last hope.
Please, with  all due respect, don't send me a link on Dinos, I've been reading about them for so long, I  know them inside out, I just don't have a cure, if one even exists.
My parameters are excellent, something I've perfected (this is my third attempt at keeping a beautiful reef!) Each tank was plagued with algae.
I do use ro/di ONLY.
I have included pictures of  the Dinos, before and after various treatments as  mentioned above, (the computer put them in reverse order, so you'll see the "after" photos first.
Also, I'll include a picture of the algae on the rock, hopefully you'll be able to identify.
<Have to look at under a 'scope... this is likely a mix of species... some BGA>
Thank you so much for your help, as you guys are always my "go to" people before I take the final plunge!
<... I'd be reviewing my system... possibly boosting pH (with Kalk) to 8.6-8.8 temporarily to precipitate out HPO4... Do you have a refugium/sump?
I'd deepen the DSB there... culture some macro-algae via RDP. Bob Fenner>

Re: erythromycin as last resort? Risky?      1/19/14
Bob,  I removed the refugium (HOB unit)  that contained "Miracle Mud" because I felt it was adding too many nutrients
<... Do you have test kits for... what? N, P, K?>
to the system (under the advice of one of your friends :) ) So no RDP going on for about 2 weeks.
<I'd put it back on, run it>
But initially, that is the way I set up the system, with loads of Chaeto added to the fuge. And this tank has been set up new since May 2013!
Maybe it was a coincidence, but since I took down the fuge, the Dinos subsided.
No sump, unfortunately. Some day......
The sand bed is 4 inches right now,....  you recommend adding (on top) of the Dinos?
<Yes I would>
Also, I DO use Kalk and throughout the four months can't seem to get the system above 8.6.
<.... something... is your Calcium very high? Like over 450 ppm?>
Ahhh, so aggravating.
<Patience. B>
Re: erythromycin as last resort? Risky?      1/20/14

> <Patience. B>
Is a virtue, ugh! I know
Thank you Bob!
<Welcome. B>

Hair algae growing inside a clam     12/3/13
Hello WWM Crew,
I have a problem with a Tridacna clam for which I haven't found an answer yet.
Some hair algae started to grow on one side of the clam. I didn't take care of it right away as I was battling these algaes all over my tank. I have now won the battle but I noticed that some algae managed to attach on the inside edge of the shell (note : the algaes I fougnt were green hair algaes, the ones remaining still look like hair algae but are red-brown and less soft than the green ones).
<Could be... most anything... not necessarily a Chlorophyte. One can't "tell" the taxonomic group (Division) of algae simply on the basis of color. Requires microscopic examination and sometimes other testing (storage foods et al.)>
 It is apparently causing discomfort to the clam as the mantle stays retracted on this area. I've tried to remove the algaes several time but I cannot get to the root so I am only breaking the tips away. It has now been several weeks and I am afraid it will eventually cause the clam to die. I have several hermit crabs and snails but they don't seem to either care for this type of algae or don't want to go inside the clam. The only solution which comes to my mind is to block the shell with a little piece of wood so that the clam cannot close it and use tweezers to thoroughly remove the algaes.
However, I am afraid this solution will stress the clam and possibly kill it. Do you have any other suggestion ?
<... this may be Cyanobacteria... or that in origin, accompaniment... This IS one case where I would avail myself the use of antibiotics... Erythromycin of a few sorts is sold in the trade/interest... I would move the clam to a system w/o other life that might be mal-affected for this treatment. Search WWM with the terms "chemical algaecides"; read particularly re BGA>
Thank you
Best regards,
<Welcome. Bob Fenner, USA>

BGA? Concern... Flako      11/20/13
Hi i have an issue with lights,and marron alge, i have all correct, so i
believe is my light  i have a 75 gallon aquarium my fixturr is an odyssea
with a hqi 250w and 2 24w t5 and 4 leds, is good or not?_
<This lighting arrangement should be fine... depending on what you're trying to accomplish, what life you have here; the age of the MH and Fluor. lamps... There is much more to algae control than lighting.... Have you searched/read on WWM re? Bob Fenner>
Mas Flako

So, i havr to keep it of most of the time
Mas Flako

What u recommend for this problem? Thx
Mas Flako

The fixture is 6 months old and is 24 inches, everything id goog, till i
turn the hqi on, all the botton start getting brown
<.... What? Read>
Mas Flako     11/20/13
How to eliminate marrone algae?

Red Hair/Brown slime in <a new> Reef Tank     8/26/13
I started up a new 72'' 165 gallon reef tank with the live rock and soft corals I had in my 100 gallon tank. I also upgraded my skimmer to one rated at 200 gallons. The new tank has been up & running for 6 weeks now and I am having a terrible time with red hair & brown algae.
<Mmm, well... "these things take time" to settle/sort themselves out. The "run in" period with new systems often involves such pest algae issues>
My nitrate, phosphate, and silicate levels are not detectable.
<These may be being "scarfed up" by the algae>
 I am using (2) 22k & (4) 420/460 Actinics,  & 2 15k daylight T5 bulbs, with the 15k lights on for 6 hours, the blues are on for 12 hours.
<Mmm, this is too much blue to suit me; and may be part of (at least a delay of/for) the issue here>
 I also have good circulation in the tank. The red hair algae just won't give up and although it hasn't completely overrun my tank, it takes a lot of effort dealing with it. Do you think it will cycle out on its own?
<In time; yes... This is actually highly likely a Blue Green algae... Best to have you read here:
and as much of the linked files above as you deem useful>
I can't imagine what's fueling it
<... BGA predates much of other life on this planet... Is able to become early-entrenched, create conditions that preclude other life from establishing>
 unless my light configuration has
something to do with it. I am using more blue light right now to help deal with it. (ps..I do not use tap water and I don't have any fish)
<Please do the cited reading... and consider some of the proffered steps toward eliminating the problematic life here.
Bob Fenner>

Algae ID, 'scope, sample, rdg.     5/29/13
Any ideas what this is? It's fuzzy and very moss-like. I have a bit of red Cyano on my substrate and figure whatever this other stuff is it'll compete for nutrients with the Cyano. It's only growing on the back of my tank and the fish don't seem to be interested in it. Should I remove it, or just leave it be?
<Likely a large mix of green/s, blue-greens, Protists... Need to sample and go over w/ a 'scope. I'd remove a good deal of it with a scraper and vacuum every water change. Bob Fenner>

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