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What is Aquaponics?
Aquaponics is the symbiotic cultivation of plants and aquatic animals in
a recirculating environment.
Aquatic animal effluent (for example fish waste) accumulates in
water as a
by-product of keeping them in a closed system or tank (for example a
recirculating
aquaculture system.) The effluent-rich water becomes high in plant
nutrients but this is correspondingly toxic to the aquatic animal.
Plants are grown in a way (for example a
hydroponic system) that enables them to utilize the nutrient-rich
water. The plants take up the nutrients, reducing or eliminating the
water's toxicity for the aquatic animal.
The water, now clean, is returned to the aquatic animal environment and
the cycle continues. Aquaponic systems do not discharge or exchange
water. The systems rely on the relationship between the aquatic animals
and the plants to maintain the environment. Water is only added to
replace water loss from absorption by the plants, evaporation into the
air, or the removal of biomass from the system.
Aquaponic systems vary in size from small indoor units to large
commercial units. They can use fresh or salt water depending on the type
of aquatic animal and vegetation.
Aquaponics is the combination of aquaculture and hydroponics. In
aquaponics, you grow fish and plants together in one integrated,
soilless system. The fish waste provides a food source for the plants
and the plants provide a natural filter for the water the fish live in.
Aquaponics produces safe, fresh, organic fish and vegetables. When
aquaponics is combined with a controlled environment greenhouse, premium
quality crops can be grown on a year-round basis, anywhere in the world.
Aquaponics can be used to sustainably raise fresh fish and vegetables
for a family, to feed a village or to generate a profit in a commercial
farming venture.
In practice,
tilapia (most commonly Nile Tilapia, or Oreochromis niloticus)
are the most popular
fish chosen for home and commercial projects that are intended to
raise edible fish. Most
green leafy vegetables grow well in the hydroponic filter. Although
sometimes selected minerals or nutrients such as iron are added, the
main source of nutrients for the plants is the fish waste. In Australia,
due to a ban on Tilapia in all states except Western Australia, natives are the most
popular fish, including
Silver Perch,
Jade Perch,
Sleepy Cod,
Murray Cod and
Barramundi. Rainbow and brown trout, while not native to Australia,
are also in use - along with fresh water crayfish such as yabby and
redclaw.
There are three major ingredients to make an aquaponic system work.
The key secret is that they all have to stay in balance with each other.
You need water, fish, clay pebbles (or gravel), your seeds and natures
secret weapon, worms!
It takes time for an aquaponic system to get into balance with better
results over time as it matures and more nutrients become available to
the plants.
When there are 50-100 fish in a tank and you feed them, they will poop.
This poop flows with the force of the water to secondary containers
where the containers fill up with water up to an overflow point and
then are dumped via a very uniquely designed siphon mechanism (no
moving parts) every 10 minutes (average) to overflow containers where
the water is pumped back to the main fish container. This flush
takes 2 minutes to empty the growing bed and the process repeats itself.
The water flows from the fish tank to containers called “growing beds”
These beds are designed to specific levels which allow the seeds to
grow into plants, vegetables and fruits. Once the system is in motion
and functioning, it needs minimal maintenance and uses little water.
The fish container and over flow containers are covered to limit
evaporation.
As the system matures, more nutrients become available.
Three inch clay pebbles or gravel fill the growing beds with an optimum
depth of one foot. There are three zones in this growing bed.
The first zone is called the “dry zone.” This is about 2 inches deep
which is on top of the maximum water level when the growing bed is at
its fullest just before the dump of water via the siphon to the overflow
containers.
The second zone is called the “root zone” This is where the roots of the
plants will grow.
The last zone is at the bottom of the growing bed and is called the
"slutch zone.” This is where the magic of nature lives, the worms! The
worms live on the fish deposits and then release rich valuable
nutrients.
The growing bed should never be filled to the top as algae will grow
and rob the system of all the good nutrients and also of its
oxygen which is necessary for the growth of all the plants.
Every ten minutes when the bed drains, oxygen is delivered through the
course of the gravel which supplies oxygen and feeds the good bacteria
and little organisms.
The first zone thus has to stay dry. When you dig with your fingers two
inches into the clay pebbles or rock, you will feel that it gets wet and
also feel the roots of the plans after some time.
The success of a healthy aquaponics grow bed in addition to worms is
sunlight. Space is limited to grow the plants so plan what you want to
grow and build your racks so you can grow vertically and in such a way
that your plants get enough sunlight. Vertical growing is a way to
maximize your space. When you cut an inch or two of chives, it will grow
back within a week.
When you choose your kind of tomato, for example, the Amish Paste Tomato
would be the best as it is a natural vine.
A very natural way of keeping the bugs and insects away from and not eating
all your produce is to mix a spoon of molasses with a gallon of water
and then add a tiny drop of dishwashing soap to it. (The soap will help
the molasses stick to the plants.) Molasses is a byproduct of sugar
refinery process and easy to find. When you spray it on your plants the
sugar content increases, and the bugs do not like this and move on.
Bugs usually like low sugar content plants. Spray this twice a week. You
will never be able to keep all the bugs and insects away and you will
lose some crop, but the little you will lose will outweigh using poisonous or
artificial fertilizer
Good bacteria converts the ammonia to nitrates and therefore
you need to test the PH in your grow bed regularly. There will be a
nutrient lock up if you get clogs in the system. This can happen in
certain areas that do not get enough oxygen and bad bacteria starts to
grow.
Large root balls can create this and this is mostly common with tomato
bushes after about 12 months. When this happens, simply pull then out,
free the clay pebbles or gravel from the roots and plant it back in.
When you have your system fine tuned and well balanced and maintained
you can expect a papaya tree to grow up to fifteen feet within 13 -17
months with beautiful papayas where you can have up to 100 pounds of papaya
from one tree. Make sure you add enough worms to your system as they are
the secret to your success, and every successful grower's best friends.
Stress is the only enemy to your fish. Most fish will live a few years
but disturbing them by catching them with nets and keep transferring
them in nets from one pond to another will stress them out and they will
die. Most fish like to be covered from the sun in a darker area.
You need to kill the parasites from the gills of your fish on a regular
basis, which will allow them to live much longer. The way to do this
is to do a shock treatment with a salt solution. Regular swimming pool
salt can be purchased from aquarium or swimming pool stores.
Most fish adapt easily in a mild salt solution, which they should be
introduced to for only a short time weekly. Parasites can adapt to this
salt solution so you should do shock treatment for only 15 to 20
minutes a week with a rather stronger solution. Dilute 2 pounds of salt
with 25 gallons of water. The best way to introduce the fish to it is to
put them in a washing basket with small enough holes that they do not
escape. Prepare the solution and do a quick transfer from your regular
water to the salt concentration. The salt also recoups their mucous
membranes. Your fish will be healthy and good to eat when you are ready
to filet them.
An aquaponics system will be fully balanced with all the nutrients and
good bacteria after a year run and it has been proven that at this
stage anything can be grown in it, depending on its natural habitat,
meaning heat and humidity for the plant you will grow. |
