Transcript NOTES_aquarium_16 1

AQUARIUMS
 FRESHWATER
1. Tank shapes:
 shapes vary
2. Conc. of water:
 More
3. Oxygen conc.:
 More
4. # of organisms:

More
SALTWATER
1. Tank shapes:
 Rectangle or square
2. Conc. of water:
 Less
3. Oxygen conc.:
 Less
4. # of organisms:
 Less
FRESHWATER
5. Amount of
dissolved minerals
 Less
6.Amount of dissolved
gases …
 More
7.Density –
 Less than 1.000
SALTWATER
5. Amount of dissolved
minerals
 More
6.Amount of dissolved
gases…
 Less
7.Density –
 More greater than 1.010
Oxygen content in the tank.
 The oxygen gets into your tank by
diffusing into the exposed surface area.
 The bigger the exposed area, the more
oxygen that will diffuse into the tank.
Saltwater System
 Salinity is the total amount of dissolved
minerals per unit of water generally stated
in parts per thousand (ppt).
 Galveston averages 29.1ppt
 Tanks need to be around 30 ppt
Recipe for salt water
 1 cup per 2 gallons of water.
 We start out slowly and add more salt over
time. Always easier to add salt than to
pour the expensive mineral down the
drain.
 When the tank water evaporates, the salt
stays behind.
 NEVER add salt water to bring the level
back up.
 Pour tap water in and wait 24 hrs. for the
correct factors to become effective.
 Salinity is never measured directly. It
must be calculated using 2 magic
numbers, the specific gravity and the
temperature.
Measuring other chemical factors in
the tanks.
 A hydrometer is used to measure the
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specific gravity (density) of the salt water.
An acceptable range is 1.015-1.025.
Higher density water will cause the
hydrometer to “ride” higher up in the water.
(The salt is pushing it up.)
Lower density will allow the hydrometer to
sink further into the water.
Measuring temperature
 The correct temperature must be
maintained at all times especially for
saltwater tropical fish.
 A heater should be used.
 Temperature is measured using a
thermometer which is on the lower half of
the hydrometer.
Measuring pH
 pH – Percentage of hydrogen ions is
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measured on a scale of 1-14.
1-6 = acid
7= neutral
8-14 = basic
Use pH strips to measure the pH of your
tanks
Ranges of pH:
 Fresh water is 7 which is neutral.
 Saltwater needs to be slightly basic,
around 8.3.
Various problems associated with an aquarium.
If the pH is not staying in its acceptable range of
7.8-8.5, there are many possible reasons:
1. A lack of bacteria in the tank.
2. Excessive organisms in tank.
3. Overfeeding (10 min. rule – take
excess food out after 10 mins.)
4.Not removing dead organisms.
5.Use of a buffer
•A buffer limits the rate at which the pH changes
and assists in maintaining a constant pH.
•Ex. of a buffer in gravel is CaCo3, calcium carbonate. The gravel is crushed
coral or oyster shell.
•When these animals were alive they extracted the calcium from the sea
water in order to make their shells or outer skeletons.
Fixing the problems:
 If your pH is too LOW, then it’s too ACIDIC
and a base needs to be added in order to
RAISE the ph.
Sodium hydroxide is used
If your pH is too HIGH then it’s too BASIC
and an acid needs to be added to LOWER
it.
Vinegar (acetic acid) is used.
Fresh water tanks:
 Only need a simple kind of physical filter.
 Water is drawn up a tube into a reservoir
and forced through a filter and then
returned via a cascading fall.
 The chemical filter can be bottled bacteria.
Salt water tanks:
 Way more complicated…
 They require an undergravel filter. It has
small slits in it and it sits on the bottom of
the tank. The gravel goes on TOP of it.
 The compressor forces water down
through the gravel. It is physically cleaned
twice…Once through the gravel and then
through the slits. Debris is trapped at the
bottom of the tank. Stinks over time!!!!
Salt water
 The good bacteria sit in this gravel at on
the undergravel filter. They CHEMICALLY
clean your water in a 3 step process.
 The 2 good bacteria are:
1. Nitrosomonas:This organism oxidizes ammonia into nitrite
as a metabolic process. Nitrosomonas are useful in bioremediation. They
are important in the nitrogen cycle by increasing the availability of nitrogen
to plants while limiting carbon dioxide fixation
2. Nitrobacters: Nitrobacter convert the nitrites into
nitrates, which are readily absorbed by the plants.
3 step chemical filtration method
1. The good bacteria eat the ammonia (a
very poisonous compound) released by the
tank animals.
2. It is converted into a less toxic
compound, nitrite. However, nitrite is still
toxic.
3. Over time, the bacteria consume the
nitrite and convert it into nitrate (is great).
The Nitrogen Cycle
Understanding the Nitrogen Cycle . . .

Nitrogen In:
 Fish and invertebrates require food
for energy.
 Burn energy with the help of O2 they
respire.
○ These processes produce waste
products that are returned through
the gills and in the urine and feces.
○ Wastes:
 CO2
 NH4 (extremely toxic to fish)
Understanding the Nitrogen Cycle . . .

Nitrogen Out:
 CO2 leaves the water through:
○ Aeration at the surface
○ Photosynthesis by aquarium algae
 Ammonia  Nitrite  Nitrate (a less
toxic compound
Understanding the Nitrogen Cycle . . .

The role of bacteria:
 Convert harmful ammonia into non-toxic
nutrients.
○ Nitrosomonas – convert ammonia
(NH4) into nitrite (NO2).
○ Nitrobacteria – convert nitrite (NO2)
into nitrate (NO3).
○ These processes together are called
nitrification.
Fish Wastes
Food
Decomposers
Mineralization by Decaying plant
Heterotrophic
Fragments and
Bacteria
Uneaten food
Ammonia (toxic)
(NH4/NH3)
Plants
Nitrates (NO3)
Nitrites (NO2)
Water
Changes
Understanding the Nitrogen Cycle . . .

What happens to the nitrate?
 Absorbed by algae
 Converted to nitrogen gas
 Accumulates in the tank –
○ Needs frequent water changes
Ammonia Testing
Fill the glass vial ¾ full of water from your
aquarium.
 Get testing solution bottles #1 and #2 and
ammonia color card.
 Place 8 drops of solution #1 into vial.
 Place 8 drops of solution #2 into vial.
 Cap the vial and invert several times.
 Wait 5 minutes and read results using color chart.
 Record results on aquarium maintenance sheet.

Nitrate Testing
Fill the glass vial ¾ full of water from your
aquarium.
 Get testing solution bottles #1 and #2 and nitrate
color card.
 Place 10 drops of solution #1 into vial.
 Cap the vial and invert several times.
 Wait 30 seconds, and shake up solution #2.
 Uncap the vial, and place 10 drops of solution #2
into vial.
 Cap the vial and continuously invert vial for 1
minute.
 Wait 5 minutes and read results using color chart.
 Record results on aquarium maintenance sheet.

 Ammonia ------ nitrite------nitrate
 Ammonia (NH3) is the most toxic and will
cause immediate harm to your critters.
 Nitrite (NO2) will cause harm, although it
will be delayed.
 Nitrate (NO3) will cause harm only after
long periods of time.
BIG HOWEVER…
 Over enough time, the nitrate levels will build
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up also and kill your fish..
Therefore, it is necessary to do a partial water
change every 6-8 weeks.
During this time, empty out 1/4 -1/2 of your
tank water and replace it with fresh water.
It will take several days to get the salinity back
to where it needs to be.
As temperature decreases in both salt and
fresh water, the absorption of gases
increases.
Lighting of your tank
 Lights are used to promote algae growth.
 Some algae is good due to the fact that a
by product is oxygen.
 However, it is a good idea to turn your light
off every now and then.
 Don’t use phosphates to clean your tank.
(Use only baking soda/fresh water rinse.)
 They lead to too much algae growth.
Tank hoods
 The purpose of tank hoods is to slow the
evaporation rate.
 Remember, when the water goes away,
THE SALT STAYS!!!!
Metals and salt water
 A Big No-no!!!!!
 Metal is very corrosive in salt water. It will
change your pH drastically and cause
death to your critters.
 Lots of commercial paints are lead based.
 Only purchase plastic items for a salt
water tank.
Parasitic organisms …Yuk!!
 Parasites become a problem when salinities
are kept too low. Salinities that are kept too
high can lead to death by dehydration.
 2 primary parasites we often encounter are:
 ICH – protozoan (kingdom Protista)
 Ich is a protozoan disease that is often called “white spot disease”.
The scientific name for the disease is ichthyophthiriasis. It is wide
spread in all freshwater fish and is very common in aquarium fish
possibly due to closer contact and stress involved with these species.
Stress lowers the fish immune system which makes them vulnerable
to disease.
 FIN ROT – fungus (kingdom Fungi)
 Infection is commonly brought on by bad water condidtions, injury, poor
diet, stress, or as a secondary infection in a fish which is already fighting
another disease.
 Both of these parasites eat the fish from
the outside in. They resemble cotton
growing on them.
 They can be treated if they are discovered
in time. Point to remember, the medicine
goes in the tank water, not shoved down
the fish’s throat!!!!
 Remember to establish a “sick” bay.
Food and feeding procedures.
 Remember that your critters are coldblooded, ectothermic. Therefore, they do
not need to eat every day.
 We feed three times a week, M, W, and F.
 You and I are warm blooded, endothermic.
 Therefore, we must eat many times a day.
(some of us more than others!!!)
Menu items
 Flake food – fish eat this
* Remember, hermit crabs do not eat this;
The flakes float and the crabs don’t.
Pellets – bottom feeding fish , crabs and
anemones eat this.
Cut up frozen shrimp- the hermit crabs eat this.
Live feeders – they eat minnows, goldfish, or live
bait
How do different life styles affect
the tank life.
 A. Competition – different species or the
same species can compete for the
following things:
 food, space, mates
 B. Predation – one is the predator and the
other is the prey.
 C. “Does not play well with others” – time
to think about another tank critter.
Anaerobic bacteria – what does it
mean for the tank.
 Anaerobic means “without” oxygen ….
 If bacteria go through the process of
cellular respiration without oxygen then
hydrogen sulfide is produced.