Algae problems
Algae (pronounced AL-jee) are simple forms of marine plant
life. They’re pretty basic: they lack leaves, roots,
flowers, seeds, and all the other things we normally associate
with plants. The term ‘algae’ is an umbrella
phrase that’s used to refer to all forms of marine
life that are capable of photosynthesis (converting sunlight
into energy), although some forms of algae rely entirely
on external supplies of energy (in the form of protein and
fish waste in the water) for food.
As far as your tropical fish tank goes, algae is definitely
an unwanted visitor – it’s a real eyesore. Of
course, certain levels of algae are to be expected; small
amounts are inevitable wherever there’s light, nutrients,
and water in combination.
However, when levels get high enough to be visible to the
naked eye, you’ve got a surplus.Unless you maintain
your aquarium regularly, you can pretty much count on regular
growths of algae obscuring your fish, making the water smell,
and generally detracting from the aesthetic appeal of your
tank.
But what is it – and how do you get rid of it?
Well, it depends on the type of algae that you have, since
each one needs to be treated in a specific manner. The most
common forms of algae to affect tropical fish tanks are:
brown algae
green algae
blue-green algae
green water
What to do about brown algae
Brown algae is usually the first to appear in a newly established
tank. It’s pretty easy to see: it looks like cloudy
brown slime growing along the sides and bottom of your aquarium,
as well as clinging onto gravel, rocks, and ornaments.
Limiting the light available won’t make any difference
to this type of algae, since it’s perfectly capable
of growing at low-lighting levels.
Instead, you need to cut right back on the nutrients available
for sustaining its growth – which means feeding your
fish less. High protein levels in the tank, derived from
fish food, will fuel this algae’s growth.
Even if your fish are eating all the food you give them,
this doesn’t mean you’re feeding them the right
amount: when it comes to food, fish are natural opportunists,
which means they’ll eat everything that’s available
regardless of how much you feed them. If they’re overeating,
they simply excrete the undigested food – which then
floats around in the tank, feeding the algae instead!
Make sure you follow the directions stringently on the fish-food
package, to be certain that you’re minimizing nutrient
levels appropriately.
In addition to keeping food levels down, make sure you’re
maintaining your tank adequately with enough water changes
and gravel and filter cleanings.
If brown algae appears in an established aquarium, you’ll
need to check the phosphate and nitrate levels, as too much
of either will encourage the growth of the algae.
If the problem remains ongoing, you can use algae-eaters.
These are bottom-dwelling fish – such as the American-flag
fish and the Siamese algae eater - which feed on algae, and
are commonly stocked by pet stores and fish traders. They’ll
make quick work of your brown algae problem!
What to do about green algae
Green algae will appear in just about any tank with plenty
of light. Fortunately, it’s easy to remove (it doesn’t
cling to the glass too much) and most algae-eaters will consume
it with gusto.
For green algae, make sure you’re minimizing the protein
in the tank, as you would for brown algae. Start by cutting
the fish-food back by one quarter, and pay close attention
to the appearance of your fish: if their bodies become flat
and thin, they’re not eating enough. They should be
getting just enough food to remain slightly round-bodied.
Keep your fish tank stocked with plenty of algae-eaters,
and the problem should take care of itself (although it bears
repeating that a certain amount of algae, particularly green
algae, is to be expected).
What to do about blue-green algae
Blue-green algae is technically not really an algae in the
true sense of the word – it’s actually a form
of bacteria, called cyanobacteria, which is a type of bacteria
capable of photosynthesis. Cyanobacteria is one of the oldest
organisms in the world, and is thought to have been around
for at least 3.5 billion years!
It looks like a slimy coating in a number of greenish-blue
shades, and the wastes it releases can actually be toxic
to your fish – another good reason to keep it to a
bare minimum.
The good thing about blue-green algae is that it’s
easy to remove manually: usually, it forms ‘sheets’ of
hanging matter in the water, which can easily be scooped
out.
The bad thing about it is that it’s pretty hardy:
even after a thorough removal, it’ll usually have returned
by the next day
This algae is usually caused by low levels of nitrates (usually
in combination with high levels of phosphate), and an imbalance
of bacteria in the water.
How to get rid of this persistent eyesore:
Block all light for a week, and siphon the dead algae out
of the tank each day. Your plants will be feeling pretty
sorry for themselves by the seventh day, but they should
recover just fine.
Add new bacteria after every water change. You can purchase
bacteria pellets for this express purpose from your pet store
and aquarium supply dealer. Ask for bacteria pellets that
remove ammonia and excess protein from the water.
Be stringent with your tank maintenance: keep everything
clean, check the filter for clogging, make sure the lights
are working adequately (blue-green algae needs light to survive,
but good fluorescents are necessary to maintain an adequate
balance of bacteria and plant life in the tank).
What to do about green water
If the water in your tank is green, cloudy, and murky, then
you have green water. This is a particular form of free-floating
algae which hangs suspended in the water, giving it that
characteristic opacity – in some cases, the water becomes
so green that the fish are obscured.
It’s usually due to a significant excess of light
(usually sunlight, as opposed to too much fluorescent), or
a problem with your water quality.
To treat this problem:
Block all sunlight from reaching your tank for several days
to one week. You can do this by draping fabric over your
tank, or making sure that all the curtains remain drawn in
the room where your aquarium is placed. This is very effective.
Keep your filter mesh as fine as you can: most generic filters
come with pretty coarse mesh, so replace it with a fine-meshed
sponge or use a diatomic filter (designed specifically to
treat algal problems). Remember to check the filter regularly,
or else it’ll get clogged.
General algae prevention tips
Regular maintenance of your tank is one of the best preventative
measures when it comes to algae:
Change the water regularly
Clean the aquarium regularly
Use a UV filter in the tank
Situate the tank away from direct sunlight
Don’t overcrowd the fish
Keep the food levels down
Minimize aeration unless your aquarium is very well stocked:
keep airstones and vents to a minimum
Utilize your plants’ nitrate and phosphate absorbing
capacity: stock your aquarium with plenty of fast-growing
species like Ambulia and Egeria
Maintaining a healthy, attractive aquarium can be a pretty
complex task – there’s so much to keep track
of!
For smart, relevant, detailed, and easy to follow advice
on keeping a professional-standard aquarium, we recommend
Katy’s
Tropical Fish – A Complete Guide.
It’s packed with valuable insider tips for keeping
a fabulous aquarium, regardless of budget and experience – all
aspects of tropical aquarium maintenance are covered, from
fish health to algae problems to fish compatibility. It’s
a complete owner’s manual!
You’ll learn how to keep your fish happy,
healthy, and beautiful, how to keep your aquarium to professional
standards, how
to troubleshoot health
problems as soon as they occur, and learn valuable insider tips and tricks
for keeping your aquarium looking spectacular.
