VISITOR'S QUESTIONS
10... Understanding Water Quality
Getting to understand the subject of water
quality and its different characteristics in the aquarium is rather
daunting at first, however, once you understand that this is just natures
way of recycling, which is an ongoing process that we are trying to
mimic in the aquarium, you will see its not that difficult at all. It
is important though that you do understand the basic principles, and
how the characteristics of water can differ from region to region and
how it can be altered in order that your fishes don't suffer unnecessarily.
First of all, the "nitrogen cycle" is never completed
as such, it is an ongoing process that cycles over and over, and never
ends. I think what you really mean is, when is the cycle working efficiently
enough to provide a safe environment for fishes to live in?
From reading your email, and pardon me if I'm wrong,
I suspect you may have a wrong perspective of the nitrogen cycle. I
will try to make things more clear by taking your last question first.
The nitrogen cycle is a process of nature, it is not
something that is unique to the fishkeeping hobby, or something that
takes a predetermined length of time, or a particular hurdle that has
to be overcome then everything carries on from there. Therefore it would
be impossible to say how quickly the cycle would be working efficiently
enough to support a specific number of fishes, the one thing that is
for sure is the fact that if fish, plants and food are introduced into
the aquarium nitrification will occur.
There is no problem with your choice of filter; provided
it is matched to your size of aquarium it will do the job. However,
your aquarium is at best only the recommended minimum size, I don't
know if your using American or Imperial measures, but the recommended
minimum aquarium size, as a suggestion, would be 24 x 12 x 12 inches
= 60 x 30 x 30cms. = Approx. 12.5 Imperial gallons. You should also
bear in mind that larger volumes of water are more stable, this could
be the reason why your daughters larger tank appears to be making better
progress.
As you said in your email; your aquarium is in its
second week, I would suggest that this is too short a time to have had
water changes. Water changes at this stage are removing the valuable
bacteria that are trying to build up a colony; it is also too early
to have introduced fishes, the fact that you have introduced fishes
into your aquarium at this stage may be the reason why you are seeing
rising ammonia levels. Try to reduce your pH to nearer 7.0 ammonia is
more toxic the higher the pH .
Bacteria will colonise anything it can cling to, including
the gravel. At this stage you should not be thinking of cleaning the
gravel, indeed at this stage there should be nothing to
clean. However you have introduced your fishes therefore only remove
any material (uneaten food etc) you may see on the aquarium floor or
floating around.
What you should have done was to leave your aquarium
and its filters to mature for at least two to three weeks. Leave all
the equipment running as though there were fish in the aquarium, Check
the water temperature after 24 hours, and adjust the heater as necessary,
keep checking daily until a stable reading of 76F (25C) is observed.
You must not add any fish until there are enough beneficial bacteria
to cope with the waste that they will produce, which is why you must
wait for at least two weeks so that these bacteria can colonise and
multiply.
Use your test kits according to their instructions
within this minimum period, to ensure you have correct readings before
introducing any fish.
- Ammonia: 0 ppm (mg/l)
- Nitrite: 0 ppm (mg/l)
- Nitrate: 50 ppm (mg/l) or less
- pH : 6.5 to7.5 (for tolerant species)
After a couple of days you may be fooled into thinking
everything is ok to introduce your fishes, because your test results
indicate low or even zero readings, remember, there are no fish in at
the moment to produce waste to give high readings, what you have to
realise is that you are actually waiting for the bacteria in your filter
to multiply, ready for the introduction of fishes.
Fish waste is high in ammonia, even in small amounts
it can kill. Bacteria feed on the waste and produce nitrites, which
are also toxic to fish; these in turn are converted into nitrates, which
are harmless at low levels, this is the process is known as the "Nitrogen
Cycle". If you introduce fish to soon there will not be enough bacteria
to break down the fish's poisonous waste. The process can be speeded
up a little by adding a bacteria culture, available from your aquatic
store, just add it to the water or into the filter.
You should also check your waters pH every three or
four days to ensure it is remaining stable. For a tolerant species community
aquarium you should have a reading of pH 6.5 to pH 7.5. I must say I
have never heard anywhere that tap water should be left a few hours
before checking its pH . There is nothing that can happen to the water
during this period that will change its pH , no matter how long its
left to stand.
Whether or not you need to alter your pH of 7.6 depends
on the species of fish you want to keep. For your "Betta" and "Corydoras"
its too high, again it depends which species of Betta and Cory they
are but in general these species share the similar pH of between 6.8
and 7.2.
When setting up a new aquarium, and/or filter, you
must monitor things closely in the first 4 to 6 weeks, especially after
adding new fish. As mentioned earlier, beneficial bacteria have to build
up, and until then a phenomenon known as "New Tank Syndrome" can occur,
and could cause problems. During this process there is a characteristic
rise and fall in the concentrations of ammonia and nitrite, with levels
possibly becoming toxic, and causing fish to become unhealthy. This
is due at this stage to fish waste and uneaten food accumulating in
the aquarium and not being broken down by these helpful bacteria. The
reason for taking things slowly and one stage at a time is to avoid
new tank syndrome.
Build the bacteria up before adding fish; only add
very small fishes at first and in small numbers. This will avoid sudden
surges of pollutants; the bacteria will be able to cope with these small
changes. This will reduce the possibility of high rise and fall levels
of pollutants associated with new tank syndrome. It is impossible to
give time scales within the hobby for any given task or query, there
is no magic time scale or specific figure, each case is individual and
its up to the individual to monitor things closely and only act only
on his/her results.
A clue towards the length of time taken to reach the
stocking levels of any new aquarium set-up would be 8 - 10 weeks or
even three months. It may sound a long time but when you consider the
end result its worth it.
In time you may find that algae has started to grow
on the aquarium glass, this should not be a problem, indeed many species
love to feed on these algae, many of the catfish for instance. Therefore
it is up to the aquarist how and when the algae is cleaned, it may be
that only the front glass is cleaned to allow a clean view into the
aquarium, and let fishes graze the algae on the other sides. However,
if the algae is unsightly and growing too fast I would suggest that
the aquarium is positioned in the wrong place and receiving too much
sunlight or there are too many nutrients in the water in the way of
nitrates, in which case water changes are necessary. Normal water changes
and good house keeping usually eliminate the latter anyway.
To sum up: The nitrogen cycle will have started in
your aquarium. It is up to you now not to over burden this delicate
process by introducing any more fishes until you have the correct readings
from your tests, or allowing debris to build up. Keep your aquarium
free of any debris, such as uneaten food. Only carry out partial water
changes at this stage if ammonia is present, reducing your pH will help
reduce its toxicity. Only carry out partial water changes at this stage
if excessive levels of nitrites are present. In time your aquarium will
build up a huge colony of healthy bacteria thus making your aquarium
conditions more robust, it won't always be as delicate as in its first
two or three months.
Suggested links on my site appropriate to your query:
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