Stress in your aquarium

Fish are subjected to stress due to various reasons. Stress weakens the fish and causes the
fish’s immunity to be greatly reduced, thereby making it susceptible to diseases. Stress
also leads to decrease in feeding. Breeding is almost non-existent in fish that show
symptoms of stress. Eventually, over stressed fish become ill and die. Thus it is best to
know the reasons of stress in your aquarium.
Stress is frequently species dependent. Some species thrive in an environment that may
weaken others. For example, if you have hard tap water, you need to purchase fish that
thrive in such conditions or alter the water conditions before you introduce your fish to
the aquarium. An unsuitable or unstable pH-value is also a common cause for stress in
aquariums. Some fish are very sensitive to changes in pH, while others are not too
susceptible to this. Always research your particular fish species in order to find out their
preferred pH-value and the span which they will tolerate. Find out the pH-value of the
water that the fish is currently living in before you purchase them and introduce them to
their new home, since fish unlike rapid changes.
As mentioned earlier in this book, increased levels of ammonia, nitrite and nitrates also
lead to stress and you will need a test kit in order to monitor these levels. We have
already discussed the different actions that will help you to keep these levels down, such
as using several types of filtration, performing frequent water changes, choosing an
aquarium that is large enough and never over-feeding your fish.
Salt can also lead to stress. Some fish species have zero tolerance for salt. As a general
rule, fish that have no scales or very small scales will not tolerate salt water. Add salt to
your water only if ALL the fish species in it can tolerate salt. Some fish species will
become more prone to illness in an aquarium with no salt, even though they are not
marine species. Fish species living in brackish waters will usually stay healthier in a
slightly brackish aquarium, even if they are capable of tolerating freshwater.
An unsuitable water temperature or temperature fluctuations can easily lead to stress in an
aquarium. Some fish are comfortable in cooler temperatures, while others require tropical
temperatures. Care must be taken while mixing up species, so that they all have a general
tolerance for the same temperature. The goldfish is one example of a fish capable of
surviving in cool temperatures, while a lot of the common beginner species – Guppy,
Molly, Tetra etc – prefer much warmer temperatures. A daily thermometer reading will
keep the temperature stable and well under control.
Physical space or the lack thereof is another factor that leads to stress. Even normally
peaceful fish species can become extremely territorial when they have to fight for space.
Also, putting in different varieties of territorial fish with similar behaviors is like askingfor trouble in a small aquarium. Introducing competition in your aquarium by adding fish
that cannot cohabit will lead to stress; and frequently death due to direct injuries or due to
illnesses brought on by the stress. Also keep in mind that the onset of the breeding period
triggers a number of changes in the fish's behavioral pattern. Some fish chase stakes out
breeding territories at this time and chase away any intruders.
What are the symptoms of stress in fish? From the very beginning, you will need to
observe the patterns of behavior of each species in your aquarium. After a few days, you
will notice that each species has a behavior particular to it. Some fish keep swimming
briskly, while others are happy staying almost stationery. Some like to be on the surface,
while others linger near the bottom. Deviation from their normal behavior is the first
indication of stress. Some fish start hovering near the surface al the time, indicating poor
supply of oxygen. A stress fish can also stay away from its usual haunts and keeps itself
hidden. Sometimes fish shows nicks or spots on their body that are not healing quickly.
Prevention is definitely a better approach than waiting until the stress begin to manifest
and then trying to cure the symptoms. So, being aware of the 'character' of your species
before you bring them home and introduce them to your aquarium will help greatly in
warding off stress. As soon as you notice any symptom, make sure to explore the cause
and remove it at your earliest. Fish that falls sick and eventually dies harms not only
itself, but also the entire aquarium. Infections can spread quickly and you may find your
fish succumbing fast to these.