Aquarium Cycling For Freshwater: What It Is (And Why It�s Important)
By unknown author
Aquarium cycling is the process that is used to grow a
colony of what is known as good bacteria, in an aquarium.
Good bacteria is essential to all aquariums because it literally eats
waste products, which would otherwise build up and injure, sicken, or kill the
inhabitants (pets) in the aquarium.
In a freshwater aquarium, there are two kinds of essential
good bacteria. The first kind
breaks ammonia down into nitrites, and the second kind breaks the nitrites down
into nitrates. In the normal cycle,
aquatic pets go to the bathroom in their own house.
They urinate and excrete directly into the water.
It would be the same as you or I urinating or excreting into the air, in
our very own houses. For the aquarium inhabitants, the most harmful waste product
is ammonia. Nitrites are also very
harmful to the inhabitants, but not as harmful as ammonia. Nitrates, in large quantities, are also harmful to the
inhabitants, but not nearly as harmful as either ammonia, or nitrites.
It is important to cycle an aquarium before you add any
aquatic pets that you have hope of keeping, in good health.
This is important because in a brand new aquarium, there are not any good
bacteria present. When the inhabitants urinate and excrete, the waste builds up
much faster than good bacteria can grow, and ammonia and nitrites damage the
gills of the inhabitants, and frequently kill the inhabitants before good
bacteria can grow. Even if the
inhabitants survive the ammonia and nitrite spikes which occur before cycling is
complete, their gills may be damaged to the point that their lives are terribly
painful, and unhealthy.
There are many methods of cycling a new aquarium.
Fishless cycling, Traditional cycling with �starter fish,� and
Accelerated cycling with commercial products are the three methods I will
discuss. Whatever method you
choose, there are things you can do to speed up the process.
1. Run the
aquarium at a high temperature, up in the low to mid eighties, Fahrenheit.
Only do this if you have no pets in the aquarium which need lower
temperatures. The higher temperature leads to faster cycling.
2. Keep the
tank only about 50-65% full. This
creates a waterfall effect as the water leaves the filter, and when the water
from the filter hits the surface of the aquarium water, there is a great deal of
water turbulence, exposing more water to more air more quickly, and leading to
increased oxygenation, and thus, faster cycling.
3. Keep the
aquarium light on 24 hours per day during cycling.
Only do this if you have no pets in the aquarium which need less light,
or which need darkness. The
increased light leads to faster cycling.
4. Use as many
air stones and air pumps as you have access to, which will fit in the aquarium.
Keep them all running all the time.
This leads to increased oxygenation, which leads to faster cycling.
Only do this if you have no pets in the aquarium which need calm, or
5. Keep the
filter running the entire time the aquarium is undergoing the cycling process.
This increases water flow, and insures that good bacteria build up in the
filter material, both of which lead to faster cycling.
I will tell you right now that I have a bias toward
fishless cycling. I prefer it, and
at the end of the section on fishless cycling, I will tell you the reasons why I
You will know when your aquarium has fully cycled, because
you will have seen an ammonia spike and a nitrite spike, and you will have zero
ammonia, and zero nitrites.
Fishless cycling involves using household ammonia and
borrowed good bacteria to initiate the cycle, without any aquatic pets in the
aquarium. There should be no
ingredients in the bottle of ammonia that is used for cycling, except ammonia,
and/or ammonium hydroxide, and/or water. It
should contain no perfumes, no coloration products, and no surfactants.
The liquid should appear clear, and when you shake the bottle, there
should be no fizzing or bubbling. I
used HomeBest Clear Ammonia, which I purchased at a Magruder�s Grocery Store.
You may not know the exact ratio of ammonia to water, in the bottle,
because frequently the bottles do not have this information on the label.
Not to worry. If the ingredients consist only of those listed above, you
have the right stuff.
The second thing you will need to initiate a fishless cycle
is some seed bacteria. If you
already have a healthy, cycled aquarium then that is the best place to steal
some good seed bacteria from. If
you do not have a healthy cycled aquarium, you may need to get some seed
bacteria from someone who has a healthy cycled aquarium, or from your Local Fish
Store. What you need is some gravel
or substrate from a healthy aquarium (about as much as will fit into a plastic
sandwich Ziploc type bag). It is
also good to get some filter pinchings from the pouch in a hang-on-the-back
filter, or filter floss or filter sponge or squeezings from a filter sponge, and
some water, both from the same aquarium you got the gravel from.
You will also need a testing kit for ammonia, nitrites, and
During a fishless cycle, the water should not be changed
until the cycle is complete, and you are getting zero ammonia and zero nitrite
readings. The only exception to
this would be if you accidentally add too much ammonia during the process.
If you accidentally do this, you will see either ammonia or nitrites off
the charts at 6-8 ppm, and they won�t come down without a water change. So if
this happens, do a 50% water change, and start the fishless cycle process over
again. Or, if you know the error you made that caused you to add too much
ammonia, calculate the number of drops you should be adding, and add that
amount, according to the recipe, which follows, in the next paragraph.
To perform a fishless cycle, add 95% of the seed gravel or
other substrate from the healthy aquarium to the gravel or other substrate in
your new aquarium. Then take the
remaining 5% of the seed substrate material, and put it into a new nylon
stocking, which you have pre-washed, in cold tap water.
Then cut most of the stocking off, so you have a little stocking pouch,
full of seed substrate material. Then
tie the pouch closed, or seal it somehow, so you have a closed pouch of seed
substrate material. If you are
using a hang-on-the-back filter, drop this pouch of seed substrate material into
the filter. Make sure the pouch
does not stop water flow through the filter entirely. Then,
add some filter material pinchings or squeezings into the water in the filter
and into the water in the aquarium.
Next, you will add ammonia.
You will need to put the ammonia into a clean dropper bottle, if it
didn�t come in one. Label that
dropper bottle immediately, with the word �AMMONIA� in capital letters.
Simply add drops of ammonia until your ammonia reading goes up to 5.0 ppm,
which is very high. It took me
about 30 minutes of adding ammonia and then testing for ammonia and then adding
drops and then testing for ammonia until I got the 5.0 ppm ammonia reading. Keep track of the total number of drops it took for you to
get the desired 5.0 reading. After the first day in which you add ammonia, you
should test for ammonia and nitrites every day. Then, every day, after testing for ammonia and nitrite, add
the same number of drops of ammonia until you see a nitrite reading.
On the first day that you actually see a nitrite reading, add half the
number of drops of ammonia that you added on the first day, and keep adding that
amount every day until you test and have zero ammonia and zero nitrites.
At that point, you will need to do a massive water change.
I did a 99% water change, and I still had to do a few more
partial water changes the same day, to get rid of the high nitrates in the tank.
A fishless cycle uses much more ammonia then would normally develop with
other methods, and therefore the leftover nitrates can be quite high.
My nitrate reading was 160 ppm when I was done with my first fishless
aquarium cycle. Don�t add any
pets to the aquarium until your nitrate reading is 10 ppm or less.
You can do multiple water changes in the same day, until the desired
nitrate reading of 10 or less is achieved.
This works because the good bacteria is in the substrate, and in the
filter, and remains after the water change.
When you have zero ammonia, zero nitrites, and 10 or less nitrates, your
aquarium is fully cycled, and ready to house your aquatic pets.
It took me three and a half weeks to accomplish my first fishless cycle. But someone who follows the above recipe, and uses all the tips to speed up the cycling process would probably be able to get it done in 2 weeks.
The reasons why I prefer fishless cycling:
cycling is faster than conventional cycling with fish.
This is because in fishless cycling, much more ammonia is used than would
be generated by the waste of fish. This
leads to a faster build up of good bacteria in the aquarium.
2. When you
are finished with a fishless cycle, you can fully populate the aquarium with
pets right away, without risk of ammonia and nitrite spikes.
This is because in fishless cycling, much more ammonia is used than would
be generated by the waste of fish. This
leads to the growth of a much larger colony of good bacteria than would be grown
by traditional cycling with fish. After
a traditional cycle with fish, aquarists need to add their pets slowly, over
time, to avoid adding too high of a bio-load too quickly and getting an ammonia
spike or a nitrite spike. After a
fishless cycle, the colony of good bacteria is large enough to fully populate
the tank with inhabitants, right away.
fishless cycling, there is no need to kill, injure, sicken, or damage the gills
of any �starter� fish. It�s
It is important to note here, that as a general rule, one
should not add more than 1 inch of fish for every gallon of tank size.
This is a general rule, for �thin� fish.
If you have �fat� fish, you may need to add no more than half an inch
of fish for every gallon of tank size. And
if you have very large fish, like Oscars, you may need to have even less
fish-inches per gallon of tank size. If
you do overpopulate a fully cycled tank, then ammonia and nitrite will still
build up, and injure, sicken, or kill the tank�s inhabitants.
Traditional cycling with fish involves getting usually 2-4
small, hardy, disposable fish, and putting them in a brand new tank.
They are there to urinate and excrete into the water, and give the good
bacteria food (waste) to dine on. This
method of cycling typically takes 4 to 6 weeks.
Many starter fish do not survive, and those that do often have no quality
of life left. Their gills are
damaged. After you have cycled
traditionally, with fish, you can start to add pets to your aquarium, slowly,
one or two inhabitants at a time. You
would need to wait a few weeks after adding your first 1-2 inhabitants before
adding the next 1-2 inhabitants. This
prevents an ammonia spike or a nitrite spike, which could kill the inhabitants.
For decades, traditional cycling with fish was the only common method
used to cycle aquariums. It is a proven method, and it will work.
In my opinion, it is just not the best, or most efficient, method.
Accelerated cycling, enhanced with commercial products that
claim to add good bacteria directly to the aquarium, and thereby cycle the
aquarium overnight have been developed, and are now on the market.
BioSpira, from Marineworld Labs, and Cycle, from Hagen, are two of the
most frequently used. Even though others have reported success with these products,
I do not recommend them because I have never seen them work well.