Photo: www.myaquaponic.files.wordpress.com
Photo:: www.greatlakespremacultureportal.com
A basic set-up for an aquaponic system.
excrete waste and respirate ammonia into water. Ammonia is
toxic to fish in high concentrations, so it has to be removed
from the fish tanks for fish to
remain healthy.
Ammonia-laden water is processed to harvest helpful types
of bacteria such as Nitrosomonas and Nitrobacter. Nitrosomonas turns ammonia into nitrite,
while nitrobacter converts into
nitrate- both of which can be
used as plant fertilizer.
Nitrate-rich water is introduced
to the hydroponically grown
plants (plants grown without
soil) plants which are placed in
beds that sit on tubs filled with
water, and the water is enhanced by the nitrate harvested
from the fish waste. The
plants' bare roots hang through
holes in the beds and dangle in
the nutrient-laden water.
The roots of the plants absorb
nitrates, which act as nutrientrich plant food. These nitrates,
which come from fish manure,
algae and decomposing fish
feed, would otherwise build up
to toxic levels in the fish tanks
and kill the fish. But instead,
they serve as fertilizer for the
plants.
The hydroponic plants' roots function as a bio filter - they strip ammonia, nitrates, nitrites and phosphorus from the water. Then, that
Aquaponics come in different shapes and sizes.
This one represents a simple but effective medium
sized system.
clean water is circulated back into
the fish tanks.
Because fish waste is used as fertilizer, there's no need for chemical
fertilizers. In fact, the only conventional farming method that's used
to operate an aquaponics system is
feeding the fish.
Aquaponics System Requirements
Many warm-water and cold-water
fish species have been adapted to
aquaponics systems. The most
commonly cultivated fish in aquaponics systems are, however, tilapia
which are tolerant of fluctuating
water conditions, changes in pH,
temperature, oxygen and dissolved
solids. They also are in high demand - this white-fleshed fish is
frequently sold in markets and restaurants.
Plants which thrive well in aquaponics are leafy greens and herbs.
The high-nitrogen fertilizer generated through fish waste allows plants
to grow lush foliage. Lettuce, herbs
and greens like spinach, chives, bok
choy, basil, and water cress do
well in aquaponics systems.
Another major component of aquaponics is the water itself. Monitoring the water's pH, which determines acidity, is of the utmost importance to ensure safe levels for
the fish. Water quality testing
equipment is also important to ensure that both fish and
plants remain healthy. It's also important to keep an eye on dissolved
oxygen, carbon dioxide, ammonia,
nitrate, nitrite and chlorine. Although the ratio of fish tank water
to hydroponic product depends on
fish species, fish density, plant species and other factors, a general
rule of thumb is a ratio of 1:4 tank
contents to bed contents. Basically,
for every one part of water and
fish, you'll want to have four parts
plant and bed material.
Some aquaponics systems are outfitted with biofilters, living materials that naturally filter pollutants
out of water and that facilitate the
conversion of ammonia and other
waste products. Other systems feed
fish waste directly into the hydroponic vegetable beds. Gravel in the
vegetable bed acts has a bioreactor, a material that helps carry out
the chemical processes of living
organisms.
Home Aquaponics
Backyard gardeners can set up an
inexpensive aquaponics system using recycled materials. For the
backyard vegetable gardener, aquaponics can offer many benefits.
These systems use much less water
than a conventional garden, and
you won't lose much water through
evaporation. Your plant harvest
definitely will be organic because
you can't use chemicals - they'd
harm your fish.