|Aquaponics is the synergetic relation of fish and plants growing together within a closed loop system. The
fish waste provides nutrients to the plants which in turn is cleaned and converted into clean filtered water
for the fish.
An aquaponic system can be incredibly productive. Our first year in production produced pounds of
vegetables, most within 45-‐60 days of planting. Our first grow bed (IBC Starter System) was no larger
than 4x4' or 16 sf'. It has since been expanded to include another media bed (32 sf'), and a raft (6sf') for
a total of 54sf' growing space.
The aquaponic system in general is simple, economical, and expandable! An Aquaponics system
eliminates bending over, watering, weeding, dirt based insects, and no fertilizers are used. My system
uses about the same power as a light bulb when running on electricity. I also have installed an additional
pump which runs continuously on solar as a backup should we lose electricity.
How it Works
Water is pumped up from the fish tank into the growbed. The water trickles down through the media,
past the plants roots and then drains back into the fish tank. The plants extract
nutrients from the water cleaning the water for the fish. Ammonia which is passed from the fish through the water is converted
from bacteria living on the rocks, granite or shale in the growbed media.
Bacteria (called Nitrosomonas) converts ammonia wastes from the fish into nitrates that can be used by
the plants. The conversion of ammonia into nitrates is referred to as “the nitrogen cycle”.
Growbeds filled with a media such as gravel or expanded clay pebbles are a common method of growing
plants in an aquaponic system, but there are many different methods that can be used. In fact any
method of hydroponic growing can be adapted to aquaponics. Plants can be grown in floating foam rafts
that sit on the water surface. Even China has developed bamboo rafts on which they grow vegetables
floating on a fish pond.
Vegetables can also be grown using "rafts" or NFT (Nutrient Film Technique), or through various other
methods, e.g. Vertical gardening. Plants like lettuce, herbs or leafy greens grow very well abundantly on
floating “rafts”. If you plan to grow tomatoes, peppers, beans or most other types of multiple yield
plants, media beds are probably your best option.
Aquaculture is raising fish in water contained in man‐made containers, including tanks, ponds, and net
Many different species of fish can be grown in an aquaponics system, and selecting your species will
depend on a number of factors, i.e., food preference, temperature, and local government regulations.
High stocking densities of fish can be grown in an aquaponic system because the recirculation of water
within the system uses very little water. Aquaponic systems generally use about 1/10th of the water
used to grow the same amount vegetables in a typical dirt garden.
There are many different types of growing media you can use in your aquaponic system, however a
couple things to consider. First the rock or media size, we prefer to use a media that is about 1/2 inch. If
the media is too small then it doesn't allow for as much air space between the media. If the media is too
large, the surface area is reduced, plus planting becomes a lot harder. Choices of media include
expanded clay, gravel, hydroton (artificially made clay pebble), crushed rock, or combinations of lava and
rock or clay. Some considerations to be aware of, some rock can have high levels of limestone and other
high pH minerals which can prevent nutrients from aligning with the rock.
Rock media or gravel is also very heavy so you need to plan to have enough support for it when building
your growbeds and their stands and supports. The advantages of rock media is that it’s readily available
and usually very cheap.
Expanded clay is extremely light, pH neutral, and can be purchased by the bag, it’s easy to plant in, easy
to clean and sterile. However it’s downside is that it's fairly expensive. Weigh the pros and cons, if you
want a quick setup and money is not a major factor, then expanded clay is the way to go. If cost is more
of a concern and you’re willing to spend more time constructing a stronger support system, and moving
and cleaning your media, then use rock and rinse it till the water runs clear.
Some folks have taken the middle road, by filling the bottom of the media bed with gravel/rock and then
filling the top 4‐5 inches with expanded clay. This cuts the costs significantly, also cuts the weight, and
makes sure that you have a nice media for planting and harvesting in.
"Main parts (techniques) of Aquaponics:"
• Rafts - also known as Deep Water Culture (DWC), where plants in styrofoam rafts float on water troughs
• Nutrient Film Technique (NFT), a fine mist of water is sprayed or dripped onto plant roots in a horizontal gutter or tray design.
• Media Bed ‐ general planting, preferred for deep root vegetables like tomatoes.
• Wicking Beds ‐ used for root vegetables.
• Fish tank ‐ for aquaculture, shrimp, fish, prawns, etc...
• Sump ‐ Lowest water collection point in the system. May also house the main pump.
• Vertical Towers ‐ an alternative means to grow leafy plants and strawberries.
Hydroponics is raising plants using soil-‐less methods like aquaponics, in that it uses circulating water with
chemical fertilizers or minerals added for the plant’s growth. No fish are involved, and so there is a
greater demand on water management. The noticeable difference is the absence of fish for the ammonia
*Definition is provided to explain the differences from Aquaponics. *No Dirt Required does not provide
this solution at this time.
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