FAQs about Marine Macro-Algae
Related Articles: Marine Algae, Algae Can Be Your
Friend, Refugiums, Avoiding Algae Problems
in Marine System, Algae Control, Marine Maintenance,
Nutrient Control and Export,
Marine Scavengers, Snails, Hermit
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"/(Cyanobacteria), Diatoms, Brown
Related FAQs: Marine Macro-Algae
Selection/Compatibility/Control 1, Marine Macro-Algae
Sel./Comp 2, & Marine (Macro)
Algae 1, Marine (Macro) Algae 2, Marine (Macro) Algae 3, Marine (Macro) Algae 4, Marine (Macro) Algae 5, Rationale, Identification, Systems, Lighting, Nutrition, Disease/Pests/Predators, Culture Algae
Use in Refugiums, Coralline Algae:
Use in Marine Aquariums, Marine Algae ID 1, Marine Algae ID 2, Marine Algae Control FAQs II, Marine Algaecide Use, Nutrient Limitation, Marine Algae Eaters, Culturing Macro-Algae; Controlling: BGA/Cyano, Red/Encrusting Algae, Green Algae, Brown/Diatom Algae,
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"Marine Aquarium Algae Control"
by Robert (Bob) Fenner
Update on Algae and Coral
Hi Bob and Crew,
I've been following the daily faqs pretty much daily for some time
now and always appreciate the great updates and the contributions from
all the crew.
I came across this article today regarding updated research in Fiji
about the chemical warfare between various forms of algae and sps
corals and thought I'd pass it on.
I found the similarity between the processes described in the article
occurring in our reefs and what happens when we have a cyanobacteria or
algae situation in our tanks very informative. I also enjoyed the
description of the Rabbitfish "quivering" in anticipation of
eating the noxious algae.
<'It's certainly a novel finding,' says John Bruno, a
marine ecologist at the University of North Carolina, "
Nah... not novel at all. Have written and read re this phenomenon for
Thanks again for being that great resource for all of us.
<Thank you, Bob Fenner>
Brown diatoms/dead snail and shrimp connection?
BGA toxicity 6/13/2011
<Ohmmm, and that's not a measure of resistance>
I've been perusing your site for some time now, as it was a useful
tool before establishing my first system and continues to be so
I've had my tank (a Biocube 29) up and running for 4 months now,
though it was a used purchase so it's "established" age
is older (it was more of a move than a purchase). My problem is as
follows. I'm on my second diatom bloom (the first happened within
three weeks of getting the tank, and was eliminated by cutting down
photo-period and avoiding overfeeding), but it's much more severe
than before. I have (had) two peppermint shrimp, one skunk cleaner, two
Perculas, one royal gramma, a bulb-tip anemone, 10 hermits (5 scarlet
legged, 5 blue), one serpent star, 3 Nassarius snails, 3 Astreas, and
one jumbo turbo snail. I also have a very small (about 2.5 inches tall)
Kenya tree, one red mushroom, a few small brown button polyps, and a
small colony of green star coral.
Over the last two days, my largest Nassarius began acting sluggish and
lethargic, refusing to burrow. A few times I found him on his back, but
he responded to touch so I left him in the hopes he'd get better
(the other two are acting normally). He finally stopped retracting when
touched, so I removed him. The same day, I found one of my peppermint
shrimp dead under a rock, and turned over everything looking for the
other two shrimp to no avail. I'm running Chemipure and Purigen in
the sump, a CPR SR3 skimmer, a Koralia Nano 425 in the display for
extra flow, and recently did a light upgrade to LEDs (this seemed to
quell the diatoms a bit). My skimmer has been producing enough skimmate
to empty every other day (much more than usual), and my water
parameters are as follows:
<Mmm, the chemotrophs in your system need "some" of the
Out of paranoia, I pulled out my multimeter and checked for stray
voltage and current, and found absolutely nothing. About a month ago,
two of my smallest hermits were found shelled and partially eaten, but
I figured that was aggression incurred while they were re-housing.
<My guess too>
The real mystery is my jumbo Turbo snail. I know the shrimp could
easily have been eaten, but his shell is completely vacant, and I
can't figure out where his body is.
<Dissolved/decomposed most likely... or eaten by the
Are diatoms toxic enough to affect the health of these invertebrates so
<Not usually, but possibly a contributing cause>
And how can I more effectively manage/eliminate them?
<Please read here: http://wetwebmedia.com/diatomalgcontfaq3.htm
and the linked files above... re the usual approaches... predation,
competition, nutrient deprivation... Bob Fenner>
re: Brown diatoms/dead snail and shrimp connection? Now BGA
Thank you, crew, for your answers!
However, after writing you and showing the outbreak to some folks at my
LFS, the consensus there seemed to be that it was Cyano and not
<Oh! Much more likely to be toxic... as you/'ll know>
As I had to move the tank last night, I took this opportunity to use a
new nylon brush to scrub all of the live rock and skim as much of the
gunk out as possible (as I was told that physically removing the Cyano
was the most effective method for dealing with it).
Are there any other steps I should take to quell the outbreak?
<Yes. Read here: http://wetwebmedia.com/bluegralgae.htm
and the linked files above re BGA control. BobF>
Codium, Mermaid's Fan, and Shaving Brush in same
I've had several tall Codium in my DT for several months, and they
are extremely healthy and growing well.
I've had a Mermaid's fan (Udotea) and Shaving brush plant in
quarantine for 5 weeks, and they are also doing well.
So today I moved them to my DT. Then, as I was researching proper
placement, I ran into a statement on WetWebMedia that macroalgae should
not be mixed in the same tank. I never hear this before. Will these
three items do well together, or should I remove something? Thanks!
<Mmm, well, this mutually-exclusive statement is too broad... There
are some types/species of such algae that are known to be
allelopathogenic (competing chemically) toward others, but the three
you list should be compatible... have seen all together in close
proximity in the wild. Bob Fenner>
Best Macroalgae 2/9/10
Hey Guys (and Gals!),
I am in the process of starting a 55 gal, refugium. It will have water
that comes in, filters thru about 8 lbs of live rock, flows into about
a 2 foot stretch of live sand (1-2 inch deep) with a few chunks of live
rock and a T5 light, goes over a baffle then under, over a half wall
into the pump area. This is a refugium for a 90 gal tank above with a
flow rate (at the pump) of 700 gph. I was wanting to get some good
macroalgae and am having a hard time tracking down the types that would
be good for this setup. I know Chaeto is all the rave, but I am
concerned it would just end up in the pump area.
<There are ways to curtail/avoid this...>
I have read thru several pages of FAQs about macroalgae, and have even
tried to do some research on it, but what I have found seems to be much
more technical than I can understand lol. :) I was wondering if you
guys would mind pushing me in the right direction, and to get your
Here are some of the things I am looking for..1.) Is not calciferous,
2.) will grow to make a refugium worthy of display, 3.) will not cause
problems, 3.) has good nutrient absorption, and 4.) will work well with
my setup,( i.e. not needing tumbling). Any input you have is much
I would prefer different colors, not just green if possible.
<Please read here: http://www.wetwebmedia.com/refugalgfaq2.htm
and the linked files above. Bob Fenner>
Would it be beneficial to feed a Potter's Angel
<Hey Korrine! JustinN here to assist!>
Since they are constantly grazing, would it be nutritionally beneficial
to feed a Potter's Angel Chaeto? Basically keep adding it to the
tank as it grazed it down?? Or they generally it not eat it? I
don't have a fuge yet, but could probably buy some Chaeto and start
<Well -- it would likely be beneficial to them if they ate it --
Chaeto holds a good deal of nutrients all-around.. Unfortunately, its
largely unpalatable, even to the most unrelenting algae consumers
let this hinder you from starting a 'fuge though! A Refugium
provides so many more health benefits than just a quick source of leafy
food -- read more here: http://www.wetwebmedia.com/refugium.htm and its
sublinks. Ciao! -JustinN>
Korrine from South Dakota
Macro causing high nitrates? 7/24/09
Hello wonderful answer-ers!
I am totally confused about the idea of placing live macro algae in the
main tank, could someone please clarify the best place to put it?
On the one hand I read that is is a great natural food for herbivores
like mine to graze on, then again, I have read here in your FAQ's
that someone did that and the thing went all "sexual" on the
tank, and the nitrites went way up because of the plant trying to
regenerate itself after feeling picked and nibbled by the fish.
<Hmmm, the only way this would happen is with improper care and
maintenance. Macro will only increase nitrate when it dies off.>
Yet, placing it in the refugium helps to reduce nitrates, and pruning
it back does an even better job of keeping the nitrites in check.
<To a point.>
But pruning is the same as a fish picking and nibbling at it in the
main tank, yet the plant doesn't go sexual in the 'fuge. How
And between the main tank and the 'fuge, which place is better to
put it to help control nitrites?
<Generally the refugium is the place to put it. Controlling the
growth in the display can be tough, and considered unsightly by many.
Do distinguish between the different macros. Using Chaetomorpha rather
than Caulerpa will avoid the issues you describe above.>
Thanks as always for your valuable insight,
<Welcome, Scott V.>
Algae for Display 3/10/08 Hi, this question
is for Scott V no real reason, he's just answered a lot of my
questions so I've come to trust him. <Hello, here with you.>
I do not have a refugium but would still like to keep various macro
algae in my display tank and I was just wondering if there were any
kinds I could keep under my pc bulbs without it getting out of control?
Thanks Scott! <Some algae grow slower than others, but all will
likely need to be controlled by periodically harvesting from your tank;
with Halimeda varieties being my personal favorites for use in the
display. More info on particular pros and cons can be found here
http://www.wetwebmedia.com/maralgae.htm and in the related
articles/FAQ'S. Welcome, Scott V.>