Tank window cleaning
by Frank Panis
|Normally there is no real
reason to get philosophical on algae in aquaria, but have you ever thought
how these micro-organisms like us and our cichlid tank? In some cases we
make them really happy campers by offering them the ideal environment to
grow or even thrive! They grow on every available surface that receives
light in our cichlid tank, including the tank windows, so our pride and
glory will look dirty and untended much faster than we ever imagined.
Elements that promote algae:
1. Overstocking: Some aquarists overstock their tank to "avoid" aggression,
what puts a lot of stress on the whole system. Many fish need more food, and
more food means more waste products: Algae-Hobbyist 1-0
2. Overfeeding: Malawi cichlids are hungry all the time and when they see
you passing, they're already on their usual feeding spot waiting for their
crispy flakes, pellets or yummy frozen food! Give in to their constant
begging means: Algae-Hobbyist 2-0
3. Poor water changes: If the owner underestimates the importance of
diluting the waste products, the algae will have an unlimited supply of
nitrates and phosphates to feed on: Algae-Hobbyist 3-0
An algae-free tank with clean windows will remain a
utopian dream, but the growth of these lower plants can be kept under
control "if" we feed sparingly, keep the fish density low, and do regular &
massive water changes. Using less light could also reduce algae growth, but
that is out of the question, as this would lead to an accumulation of even
more waste products, what will stress the fish even more. On the contrary, a
good light source will propagate the growth of green algae that are eagerly
eaten by most Mbuna species. I even have pictures from Fossorochromis
rostratus that eat from green algae from the rocks in my previous 1000L
tank. Chemicals to eradicate algae should clearly be avoided, as they're
harmful to the fish, and there isn't done anything about the real cause.
So how are we going to clean the inside glass
surfaces? Everyone will probably have their favourite method, but still I'd
like to make a small roundup of my and other people's experiences with all
kinds of cleaners. I divided the tools in 2 categories: the commercial
products and DYI tools. Keep in mind that we're not supported by any of the
manufacturers. Also I didn't list all available cleaners, what would be
impossible anyway. Take into account that there are even subtypes of the
same model (e.g. acrylic vs. glass).
|1. The classic magnet
Principle: 2 Elements that attract each other
by magnetic force are coupled on both sides of the window. The element with
the smooth face is kept outside and the element with the rough face is put
in the tank. When you make smooth circular movements with the exterior
element, the inner element will follow and will rub the algae off the
The classic magnet cleaner. The pic below shows the smooth
& rough face.
My experience: I've used them for quite a long
time, but got disappointed by them. Most of the models don't have enough
pulling power, so when you get a bit overenthusiastic and want to ramp up
the cleaning speed, they usually come loose and the inner element will fall
into the sand. If you pick it up again without thorough cleaning, the tiny
sand particles will scratch the glass and damage it permanently. You're
supposed to keep your hands out of the water with this tool, but as the
inner element will come loose from time to time, they're going to be wet
|2. Mag-Float floating
Principle: 2 floating elements that attract
each other by magnetic force are coupled on both sides of the window. The
element with the smooth face is kept outside and the element with the rough
face is put in the tank. When you make smooth circular movements with the
exterior element, the inner element will follow and will rub the algae off
the window. The floating feature undoes all disadvantages of the classic
The midsize and large model in my tank. Both perform well,
but the largest one is clearly the best.
My experience: This very useful tool comes in 3
sizes, and I have both the midrange and the top model. The midrange model
doesn't have enough pulling power in my opinion, so when you get a bit
overenthusiast and want to ramp up the cleaning speed, it comes loose. No
problem of course, because it rushes directly to the surface without picking
up a single grain of sand. Of course it can always get contaminated with
sand, but this only happens when you stir the sand near the window on
purpose. The top model is the one that I really recommend. It can handle
relative strong & brutal movement before it comes loose and is extremely
effective in removing algae. You can keep your hands out of the water with
this tool and the only downside I can think of is the price tag. It's also
the only possible cleaner for a tank that's built into a wall or other
set-ups where you can't reach the front glass by hand.
|3. Tetratec GS glass
Principle: A fibreglass stick with a tilting
stainless razor blade is pressed against the inside of the aquarium. When
you move it up and down, the blade scrapes off the algae.
Tetratec GS glass scraper seen from 2 sides.
My experience: This tool fails a bit in it's
main purpose, as it takes quite some time & effort to finish the cleaning
job in a really large tank. The best results are obtained when the stick is
pulled up while scraping the algae. A lot of pressure is needed to handle
the more tough algae, what causes the plastic retention clip to wear out
pretty fast, so the blade isn't supported very well after some time. Also
the algae start growing again sooner as with other cleaning methods and you
see the scraping patterns, what's shows that they're cut superficial instead
of thoroughly removed. The stick is unbreakable though, and it floats when
it's released. When used normally, you can keep your hands out of the water
with this tool. Also it doesn't damage the silicons in the corners of the
|4. Kent marine Pro scraper
short & long:
Principle: A metal blade is used directly to
clean the glass. This blade is mounted in a short or long handle for better
ergonomics and also for protecting yourself against cutting wounds.
2 algae scrubber models from Kent Marine. Photo by George
George's experience: The two
models shown are the one with the long handle and the one without it. Kent
Marine offers two kinds of blades one for acrylic and one for glass. The one
shown in the pictures is the metal blade used for glass panels. Extremely
useful, it will remove even the most stubborn algae spots from the glass.
The short one has a better "feeling" in the hand but will get you wet.
|5. Algae scrubbing pads
Principle: Rub off the algae on the inside
glass surfaces by gently pressing them against the glass and make circular
Commercial algae scrubbing pads...
My experience: Effective. They
claim that the glass surface won't be scratched, but they also pick up sand
very easily when you want to clean the window near the bottom. They're not
as cheap as the domestic versions though, but they should be safer in
|1. Domestic cleaning
Principle: These pads have a soft and a rough
side. We use the rough face to rub off the algae on the tank window.
Domestic cleaning pads
My experience: Can be effective, but they also
pick up sand very easily when you want to clean the window near the bottom.
I'm not sure, but the rough layer isn't also completely innocent in damaging
the glass, but I think it's mainly sand that gets picked up that can ruin
the glass though. I'm not going to discuss this, but when you let this pad
dry completely and you shake it, you'll always see sand falling out. They're
very cheap though, so you can replace them regularly. Always wash them
before using them the first time to be sure no harmful chemicals are
introduced in the tank.
|2. Wads of synthetic
Principle: Just take a small portion of
synthetic filtration wool and squeeze it together. Rub off the algae on the
inside glass surfaces by gently pressing the wad against the glass and make
My experience: Can be effective, as the white
colour of the wool makes it easy to determine if there are still green dots
on the window. Needs a lot of pressure to be effective with persistent algae
dots though, so it can be exhaustive to clean a large tank. Needs allot of
attention to prevent picking up the sand that can cause permanent damage of
the window. It also looses fibres very easily that float in the water, but
these will normally get sucked into the filter.
|3. An old credit
card: idea from readers of the EAC list
Principle: The relative stiffness and the size
of an EXPIRED credit card make it very easy to handle & suited as an algae
Their experience and comments:
Kevin: I use an old credit card. I get better use out of it that way.
Much cheaper using it as a scraper than a credit card.
Tilly: I use a credit card.
Probably why I can't go out and buy more tanks and fish!!!
George: I have used it with great success, too, especially
in the marine tanks where the algae accumulates under the glass covers. Very
handy indeed. Just remember to use an expired card!!!
Luc: I use the credit card too, but my arms are not long enough to
remove the algae everywhere on the glass, so I took a plastic electric pipe
from 50cm long and 15mm thick and with a metal saw I've cut a 3cm slit. I
inserted the credit card in that slit and I glued it with hard plastic glue,
so the credit card is fixed in the pipe, and it's more easy to work with.