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Algae
----------------------------------------------------
- by Louis Hemmi (reprinted with permission)
Scope
=====
The scope of this examination - common algae varieties found in
freshwater aquariums. This may be reposted in the conference
periodically, with sections hopefully contributed by participants, not
just the host. This is YOUR conference. Please feel free to add to or
question whatever you see here. The host is not an expert, but more of
a researcher-cum-editor.
Algae, Varieties of
==================
Some algae are "good", and others are "bad." In a well-maintained
aquarium, most algae lies somewhere between these extremes. A minor
presence of beneficial algae will be found as a consequence of good
water quality and is easily kept in balance by algae-grazing animals or
simple removal during maintenance. This algae is a natural result of
having a container of nutrient-rich water and light.
"Bad" algae either indicates poor water quality or is a type of
algae that tends to overrun the tank and jeopardize the aesthetic
benefits the aquarist is trying to effect. The label of "bad" is
relative. For example, one type of green, hair-like algae is
deemed a pestilence by some American aquarists, yet is
promoted by European aquarists as a valuable addition to most tanks,
serving as a food source for the livestock.
Blue-green, slime or smear algae
--------------------------------
Forms :Rapidly in bluish-green, slimy sheets and spreads rapidly
over just about everything.
Indicates:Usually, poor water quality. Blue-green algae can be
beneficial by fixing nitrogen and may be seen in aquariums
without measurable nitrates. Sometimes seen in small
quantities between the substrate and aquarium sides. Like
the blob from outer space, this smothers and kill plants.
Strategy :Treatment with 200 mg of erythromycin phosphate per 10
gallons of water will usually eliminate blue-green algae but
some experts feel it may also have adverse effects on the
biological filter bed. If erythromycin is used for
treatment, ammonia and nitrite levels should be carefully
monitored.
This manifestation is in reality cyanobacteria. It can be
physically removed, but this is not a practicable long-term
solution, as the aquarium conditions will likely enable it to
thrive, and so it will return quickly.
Brown algae
-----------
Forms : These diatoms appear as soft brown clumpy patches in
freshwater aquariums.
Indicates: Lack of light or an excess of silicates
Strategy : Increased light levels will usually make it disappear.
Easily removed by wiping the glass or siphon vacuuming the
affected area.
Film algae
----------
Forms : On the aquarium glass and forms a thin haze.
Strategy : Easily removed by wiping the glass. Considered normal with
the higher light levels needed for good plant growth.
Spot algae
----------
Forms : In thin, hard, circular, bright green spots, usually on the
aquarium glass but also on plants under high light
conditions.
Indicates: Normal for planted tanks. Must be mechanically removed.
Strategy : On acrylic aquariums, use a cloth pad or a gentle scouring
pad like a cosmetic "Buff-Puff" and a lot of elbow grease.
On glass tanks, scraping with a razor blade is most
effective.
Fuzz algae
----------
Forms : Grows mostly on plant leaves as separate, short (2-3mm)
strands.
Indicates: Considered normal. It might be a less "virulent"
form of "beard" algae. Strategy: Easily controlled with
algae eaters such as black mollies, otocinclus, pekoltia
and siamese algae eaters.
Beard algae
-----------
Forms : Grows on plant leaves and is bright green. Individual
strands have a very fine texture but it grows in thick
patches and looks just like a green beard. It grows up to
4 cm. It cannot be removed mechanically.
Indicates: This does not indicate bad water quality but grows very fast
and overtakes the tank, making it a "bad" alga.
Strategy : Can be eliminated with Simazine (Aquarium Pharmaceuticals
"Algae-Destroyer").
Hair algae
----------
Forms : Grows in bright green clumps in the gravel, around the of base
plants like Echinodorus and around mechanical objects. It
has a coarser texture than "beard algae". Beard algae will
ripple in the water current, hair algae tends to form matted
clumps. Individual strands can get to 5 cm or more.
Strategy : Easy to remove mechanically by twirling a toothbrush in it.
Can be troublesome if left unchecked. This is a popular
food supplement for fish among European aquarists.
Thread algae
------------
Forms : In long, thin strands up to 30 cm or more. Tends toward a
dull green color (hard to tell because it is so thin).
Indicates: Usually, too much iron (>0.15 ppm).
Strategy : Easily removed with a toothbrush like hair algae.
Staghorn algae
--------------
Forms : Looks like individual strands of hair algae but tends to grow
in single branching strands like a deer antler and is
gray-green. Seems to grow mostly on tank equipment near the
surface.
Strategy : Difficult to remove mechanically. Soak affected equipment in
a 25% solution of household bleach and water to remove it.
Brush algae
-----------
Forms : This grows in feathery black tufts 2-3 mm long and tends to
collect on slower growing leaves like Anubias, some
Echinodorus and other wide leaf plants. Also tends to
collect on mechanical equipment. This is actually a red
alga in the genus Audouinella (other names: Acrochaetium,
Rhodochorton, Chantransia).
Strategy : It cannot easily be removed mechanically. Remove and discard
the affected leaves. Equipment can be soaked in a 25% bleach
solution, then scrubbed to remove the dead algae. Siamese
Algae Eaters (Epalzeorhynchos siamensis) are known to eat
this algae and can keep it in check. A more drastic measure
is treatment with copper.
Green water
-----------
Forms : Green unicellular algae will sometimes reproduce so rapidly that
the water will turn green. This is commonly called an
"algae bloom."
Indicates: Too much light, such as direct sunlight.
Strategy : An algae bloom can be removed by filtering with micron
cartridges or diatom filters. UV sterilizers can prevent
the bloom in the first place. Green water is very useful in
the raising of daphnia and brine shrimp.
Algae Prevention
----------------
Algal spores are everywhere and will always be present in an aquarium
unless Draconian measures are taken. For fish-only tanks, a
properly set up UV sterilizer will kill algal spores in the water and
prevent them from establishing a significant presence.
For planted tanks, this is not a good solution since the UV light will
also oxidize trace elements needed by the plants and will limit the
plants' growth potential. Naturally, conditions that are good for
growing plants are also good for growing algae. Fortunately, plants
will usually beat out algae in the fight for the available nutrients.
However, if there is an imbalance of nutrients, algae will use whatever
is not used by the higher order plants. Different algae will utilize
different nutrients, causing sporadic outbreaks of new algae types in
apparently stable tanks when a temporary imbalance occurs.
Prevention is far easier and more effective than eradication. To avoid
introducing a new algae type to a planted tank with new plants, a
simple bleach soak seems to work well. Mix 1 part bleach in 19
parts water and dunk the new plant in it for 2 minutes. Immediately
rinse the plant in running water, then immerse it in water
with a chlorine remover added to neutralize any remaining bleach. This
will kill the algae and only temporarily slow down a healthy plant.
Plants in poor condition may die from this treatment, but they probably
would not have survived regardless.
Algae Eaters
============
The most effective control of algae in a planted aquarium is the use
of algae eating fish. It is especially critical in the set up of a new
tank to make sure algae does not get established before the plants have
had a chance to establish themselves. For this reason and to help the
biological filtration get a good start, add some hardy algae eaters
early on.
Black mollies
-------------
Black sailfin mollies are excellent candidates for the break-in period
of a planted tank since they are cheap and easy to find. They are
usually considered expendable and are removed after a month or so. It
is important to NOT FEED THEM. If they are fed, they will not be
quite so eager to consume algae. When they are hungry, they are eager
consumers of most algae types seen during the break-in period.
Otocinclus sp.
--------------
Otocinclus are diligent algae eaters, but are best kept in schools
due to their small size. One per 10 gallons is a useful rule of thumb.
Various species of otos are seen in the shops at various times; most
are good algae eaters but some are said to prefer the slime coat on
fish to algae. Unfortunately, there seems to be no way to distinguish
the "bad" otos from the normal otos.
Some have reported Otos to be delicate fish, but this may be due to
capture and shipping abuse rather than an inherent weakness. When a
fish shop gets some in, it is wise to wait a while before purchasing to
account for die offs. Some people report getting a dozen and having
them die over a period of a few months until just a couple are left.
Those then seem to survive a long time.
"Plecostomus" sp.
-----------------
Plecostomus is the generic name for a wide range of sucker-mouthed
fish. Only the smaller types are useful in a planted tank, since the
larger varieties tend to eat the plant along with the algae. Two
common types that are useful are the "bristle-nosed plecostomus" and
the "clown plecostomus" or Pekoltia. Both stay under 4" long and don't
seem to cause much plant damage. You may observe broad-leafed
plants being scraped too closely by the plecos, so they warrant some
monitoring.
Their diet can be supplemented by blanched or frozen spinach and bottom
feeder tablets. They also appreciate a chunk of driftwood in the
aquarium to satisfy their need for cellulose. I know of one guy who has
been awakened by the sound of his large pleco gnawing on driftwood in
an aquarium two feet from his bed !
Siamese Algae Eater
-------------------
Siamese algae eaters, Epalzeorhynchos siamensis, is a very good algae
eater and is known to eat black brush (red) algae. However, these fish
may be hard to find. The two prevalent fish in this family include
the commonly seen Epalzeorhynchos kallopterus, (Flying Fox) and the
Siamese Algae Eater.
The Flying Fox is the more attractive of the two. It tends to have a
brownish body with a very distinct, sharp-edged black stripe with a
distinct, thin gold or bronze stripe above it. These tend to be very
aggressive when they are full grown and don't eat red algae (as far as
one aquarium reference is concerned).
The Siamese Algae Eater is the same shape as the Flying Fox but
tends toward a silverish body with a somewhat ragged black stripe.
There may be an indistinct gold or bronze stripe above the black.
These are truly not aggressive and are good tank mates for discus and
small tetras.
When they are young, the differences between E. kallopterus and E.
siamensis are slight, especially if you haven't seen both types
together. Unfortunately, most wholesalers don't sell fish to stores by
their scientific name and the common names that are used sometimes get
pretty silly (like "siamese flying fox"). If you really can't tell
which one the store has, buy it anyway, but be prepared to sacrifice it
if it turns out to be the wrong kind (unless your fish aren't bothered
by it, of course).
Farlowella
----------
Farlowella are useful algae eaters although they are very sensitive to
water conditions. They type known as the Royal Farlowella will get
too large for a plant tank and may cause damage.
Happy Fishkeeping !
■ Louis Hemmi - ILink Aquarium Conference Host ■