Featured in this AN A Low-Cost Concrete Ring Aquaponics System Options for Small-scale ...

12 Pages·2014·7.66 MB·English

Asia Notes
A Regional Supplement to
ECHO Development Notes
Edited by Abram Bicksler and Rebecca Garofano October 2014 | Issue 22
Featured in this AN
1
Letter from the Editor
1
A Low-Cost Concrete Ring
Aquaponics System
7
Lessons Learned from
Cement Ring Aquaponics
Systems in Northern Thai-
land
9
Selections From the ECHO
Options for Small-scale Aquaponics:
Asia Seed Bank
Letter from the Editor
10
Book Review: Edible
by Abram Bicksler, Ph.D., Director of the ECHO Asia Impact Center
Leaves of the Tropics
Over the course of recent years, we have for use in agriculture, we encourage you, 11
2015 Indonesia Sustain-
received much interest from practitioners in our members, to remember that agricul-
our network looking for small-scale, inex- ture is very environmentally and culturally able Agriculture Workshop
pensive, appropriate aquaponics systems specific. What works well in one location
11
that can be used in a variety of situations may not work in another location or may 5th Biennial ECHO Asia
throughout Asia. This ECHO Asia Note is need to be adjusted and adapted. We invite
Agriculture & Community
dedicated to the background, creation, and you to share your experiences and lessons
Development Conference
use of small aquaponics systems with the learned with us so that we may better be
intention of helping others to set up their able to help others in our network. We hope 12
ECHO Asia Notes Now
own systems. As with all ECHO Asia ideas you enjoy this issue!
Available in Vietnamese
A Low-Cost Concrete Ring Aquaponics System
12
Seeking Applicants:
by Preston Coursey
ECHO Asia National Volun-
[Editor’s Note: Preston Coursey is originally plants, while the plants in the system filter teer Program
from Atlanta, Georgia. He graduated with byproducts from fish excrement out of the
a degree in geology with an emphasis in water, which can otherwise accumulate to
hydrogeology from the University of Georgia toxic levels (Figure 1).

Southern. He currently lives in Chiang Mai
and helps local Thais find resourceful and After telling people this explanation, I am
creative ways to enhance their own farming often asked, “So, do the plants eat fish The ECHO Asia Impact Center
capabilities. He is currently researching poo?” The answer is no! Fish excrement operates under ECHO, a non-profit
aquaponics and green water technology, is largely made of ammonia. A group of Christian organization that helps
hoping to find appropriate and viable tech- bacteria called Nitrosomonas spp. trans- you help the poor to produce food
nologies for Thais to use in order to help forms the ammonia into nitrite (Figure
them work toward self-sustainability.] 1). Another group of bacteria, called in the developing world.
Nitrobacter spp., turns nitrite into nitrate
(For more information about the roles of ECHO Asia Impact Center
What is Aquaponics?
these bacteria, see: http://dev.brighta- PO Box 64
In aquaponic systems, both fish and plants grotech.com/?p=1826). The plants in the Chiang Mai 50000 Thailand
are grown. The fish are typically in a fish system consume the nitrate, one of the [email protected]
most plant-available forms of nitrogen.
tank, and the plants are separated from www.ECHOcommunity.org
In this way, the water is cleaned and can
the fish in a trough or grow-bed. The fish
be reused without becoming toxic to the
in the system provide nutrients to the
Figure 1. Diagram of aquaponics systems. Used instead of open water, the trough is full of meter fish tanks by PVC piping (elements 1
with permission from backyardaquaponics.com. rock (typically river rock). With this system, and 2 above). We also have three smaller
seeds are planted directly in the rock and stand-alone aquaponics units that we use
do not have to rely on cups. Typically this as example starter units. One of our major
system works in conjunction with a bell goals is to help others understand how
siphon (which will be discussed further).
aquaponics works. We accomplish this by
3. PVC System – This type of system goes by presenting aquaponics in a way that is easy
many names. We call it NRT, which stands to understand and replicate. Our Concrete
for nutrient-rich technology. In this system, Ring System, a rock bed system devel-
we use PVC pipes as the “grow beds.” oped by Scott Breaden at his home and
The system looks a lot like the hydro- at the ECHO Asia Impact Center, accom-
ponics systems that grow lettuce in pipes, plishes this goal. It has helped us cut down
which can often be found in greenhouses on building costs, simplified the system,
throughout the world. While both hydro-
and allowed us to use locally available
ponics and aquaponics systems produce
materials.
plants, the nutrients to feed the plants in a
hydroponics system come from organic or
synthetic fertilizers dissolved in the water. How does a Concrete Ring
In an aquaponics system, the nutrients to System work?
feed the plants come from the fish excre-
fish. Both Nitrosomonas and Nitrobacter
ment. This PVC system requires the use of The Concrete Ring System at our site is a
bacteria occur in water naturally. They are
filters! If no filters are used, the big pieces small aquaponics unit that uses concrete
extremely important and make an aqua-
of solid fish excrement will clog up the rings with bottoms to hold water, instead of
ponics system possible; without them,
roots, reducing nutrient uptake and causing fish tanks or plant troughs.
levels of ammonia would escalate until fish
water flow issues throughout the system. In
in the system would be harmed and even- my opinion, the PVC aquaponics system The system at our site uses three concrete
tually killed. is good for shallow-rooted plants such as rings for the bottom (as the fish taks),
lettuce, but not for long-rooted plants like and two concrete rings (as the rick beds)
Even with the presence of Nitrosomonas tomatoes. If the roots are really long, they elevated on top of the bottom three. In the
and Nitrobacter, too much fish excrement will travel throughout the system, clogging it
bottom of the system, the outer concrete
in an aquaponics system will cause prob- and causing issues for other plants.
rings are used as fish tanks. We are currently
lems. In our larger raft system and rock
raising catfish in these tanks (see the fish
bed system, we use filters to remove the Our Farm
section, below, for details and reasons). A
larger, solid pieces of fish excrement. Too
PVC pipe connects all three concrete rings
many solids can get caught in and start Currently, we have two 16 x 1 meter
at the base of the unit, allowing water to
to cover the root structure of the plants, floating raft troughs, and one 16 x 1 meter
flow between the three rings at the bottom
rendering the plants unable to absorb as rock bed that are connected to six 1 cubic
and creating an equilibrium level among
many nutrients as they need. After some
time, fish excrement solids can even start
to clog drains and piping, creating flow
issues. Using filters in a larger system will
dramatically reduce these issues. For more
information about some of these filtration
systems, see www.backyardaquaponics.
com.
The beauty of aquaponics is that you can
build a system any way you want. In my
experience, there are three common types
of aquaponics systems. Elements of each
type of system, described below, can be
mixed and matched to create a hybrid
aquaponics system.
1. Floating Raft System – This system has an
open trough of water in which plants float
on a raft (usually made of Styrofoam). The
plants are typically in 1- or 2-inch cups
that sit in holes drilled into the raft. Plants
grow above the raft, while the roots are
submerged in the water underneath the
raft; the latter remove nitrate and filter the
water, which is recycled to the fish.
2. Rock Bed System – This system is a trough (top left and right) Photos of ECHO Asia’s aquaponics system (a hybrid rock bed and PVC system)
system just like the floating raft system, but and Preston’s aquaponics system (a rock bed system), respectively. (below) Figure 2. A diagram of
the Concrete Ring System.
2
. . . . . . .
the three rings. We use a plastic fencing Specifics of the System
material at the opening of the pipes, to keep
fish from swimming through them. In the
Concrete Rings
middle bottom ring, a water pump transfers
water from the bottom of the unit to the top.
For our specific system, we used concrete
We use a 50-watt pump with a maximum
rings that are 80 cm (31.5 inches) wide and
head (height of water) of 3.0 meters and a
40 cm (15.7 inches) deep. In Thailand you
maximum flow of 2500 Liters per hour.
can buy them with bottoms, so they will
hold water. They are usually waterproof, but
The top of the unit consists of two concrete
we use a coal tar epoxy paint to help seal
rings. We have filled these two rings with
the ring. The coal tar epoxy also helps to
rock (see descriptions below); this is where
prevent changes in pH caused by concrete
we grow our plants. We have also installed
(discussed later). This is the same type of
a bell siphon in each of the top concrete
material that is used to help protect boats
rings. As the bell siphon starts to work, the
from leaking. The coal tar epoxy we use
water is sent from the top of the system
needs to sit for at least two days before
back down to the bottom rings. A continuous
filling the rings with water or rocks.
water cycle is created as water flows from
the top of the system to the bottom using
gravity, then is pumped back to the top. Grow beds
We use the top two concrete rings of the
Why We Built this Unit
system as grow beds. They are filled with
river rock up to approximately 2 inches from
Aquaponics can be a great alternative to
the top of the ring. The water in the grow
farming or traditional gardening where land
bed should only be allowed to fill to approx-
is limited, but starting an aquaponics unit
imately 3 inches from the top of the ring,
can seem extremely complicated at first
allowing the top layer of the rocks to stay
glance. We want to simplify aquaponics
dry. By doing so, you will cut down on the
and enable individuals to successfully
amount of algae that grows in your system.
begin experimenting with it. In our quest for
In our system, the height of the water
simplicity, we have focused on four areas:
column inside the grow bed is controlled by
cost, material availability, size and rele-
the height of the standpipe in the bell siphon
vance.
(see below). In these grow beds, you can
grow a variety of different vegetables, either
Cost is a major factor in sharing any type of
planting seeds directly by hand, or growing
technology; if the cost is too high, no one will
seedlings on a tray and transplanting them
be interested. Aquaponics often requires a
into the system. We have had good success
high initial investment because of construc-
with tomatoes, lettuce, Chinese cabbage,
tion costs. However, one type of material
Photos: Top view of the Concrete Ring System.
cucumbers, peppers and Chinese kale.
that is very cheap in Thailand is concrete.
It is locally available and Thais have a lot find in Thailand, and relatively inexpensive
of experience working with concrete. In Rocks (five baht / $0.15 USD per fish). They are
Thailand, you can buy concrete rings of all easy to take care of—they do not require
different sizes. Thais use these for planting We use river rocks, which are locally avail- an (expensive, energy-intensive) air pump,
trees, filtering water, and storing water. able in Thailand. I would recommend buying because they require little dissolved oxygen
Thais even sell concrete rings with bottoms some type of river rock because they tend in water in to survive. Our bell siphon alone
already on them, so they can hold water. to be durable. For the most part, river rock is creates enough dissolved oxygen in our
By using these concrete rings, we have cut made up of quartz, which has a very stable system for the fish to live.
the cost of a small home-sized unit down molecular structure and does not erode
significantly. The size of the unit is based easily. Other types of rock may break down Although catfish are easy to take care of,
on the size of the concrete rings, so this and cause issues with your pump or fish. I in other ways they can be difficult. I recom-
unit can be adjusted in size by using larger would suggest buying rocks that are as big mend buying younger, smaller catfish,
or smaller rings. The number of rings can as your thumb, but smaller than your fist. because bigger ones will fight and kill each
also be customized. Our current concrete These should be large enough to avoid any other for dominance when introduced to
ring system only uses five rings, but the water channeling effects in your system, a new tank. Also, you will need to match
system can be expanded to use more. but small enough for seeds to successfully your fish stocking density with the stage
By keeping the system at the smaller size grow into your beds. and capacity of your grow bed. [Ed: see
of five rings, we are keeping the system EAN #20 for helpful information on stocking
simple and easier to understand, while still Fish densities]. Finally, catfish like to jump out of
showing how the system has the potential their containers, so you will need to create
to be expanded. Many different types of fish can be used in a simple cover for your concrete rings.
an aquaponics system. We use catfish in The cover can be anything from a plastic
our concrete ring system. They are easy to trash can lid to a fabricated cap, to plastic
3
Asia Notes Issue 22 . . . . . . .
or metal netting, but just be sure it can be will help you understand how bell siphons
taken off and put on easily so that you can work (http://www.youtube.com/watch?v-
feed and harvest fish. =lyrvcCqv5V0).
We feed the catfish store-bought fish feed Take the time to understand how a bell
that costs 550 baht ($17 USD) per 20 siphon works. At our site, we use a bell
kg bag. It contains 32% protein, and we siphon with a 1-inch standpipe and a funnel
also use it with tilapia in a larger aqua- at the top, to help with small changes in flow
ponics system. Fish feeds contain different rates. The height of the standpipe will deter-
percentages of protein; you will need to find mine the height of the water column inside
the appropriate amount for your fish. As the the concrete ring. The standpipe should be
percent protein increases, the price of feed at least 2/3 the height of the concrete ring.
will increase as well. However, the lower The bell, or outside pipe, is made from 2
the protein percentage, the less growth you ½-inch PVC pipe with a cap. The standard
will see in your fish, and the fish excrement rule for bell siphons is to always have a
will produce less nitrogen. In other words, 1:2 ratio, so if the standpipe is 1 inch, the
fish growth and the amount of nitrogen in bell must be 2 inches. However, we use a
a system are proportional to the amount of 2 ½-inch bell to accommodate the funnel
protein in the fish food you are using. Take on the standpipe. Also note that the bell
note that fish can only absorb up to a certain must be at least 2 inches taller (measured
percentage of protein in their feed. Tilapia, from the inside of the bell) than the stand-
for example, cannot absorb all the protein in pipe and funnel inside the bell. If it is not 2
a feed that is higher than 32% protein. Pick inches higher, the bell siphon will not work.
the correct type of fish feed for the species Finally, for a successful bell siphon, the
of fish you want to raise. [Editors’ Note: See outflow pipe (the piping underneath) needs
ECHO Asia Note #20 for more information to have an elbow, or trap. The elbow helps
and ideas about creating your own on-farm restrict the outflow flow rate, which will help
fish feeds.] the siphon activate. If you do not want to
use an elbow, you can use a straight pipe
Ours is a small system used only to educate restrictor to achieve the same effect. See
others about aquaponics, so we are not http://www.instructables.com/id/How-To-
interested in harvesting fish. Because of Build-A-Bell-Siphon/ for information on how
this, we give the fish only 50 grams of food to build a type of bell siphon.
per day for the entire system. As a rule of
thumb, if the fish have not eaten all of the We installed a guard around our bell siphon.
food in five minutes, you are giving them The guard is a 6-inch PVC pipe, cut to fit
too much feed. The more you feed the fish, around the bell siphon. We drilled holes
the more excrement they will produce, and into the pipe in order to allow water flow,
you will need either a more intense filtra- but keep rocks out. The guard helps protect
tion system or plants that can deal with our bell siphon from being clogged by plant
more nitrogen (larger plants require more roots. We use a 6-inch PVC pipe because it
nitrogen). is easy to stick a hand inside and pull away
roots that may be clogging the bell siphon.
Here is a great video for understanding
which fish to use and what type of food to Bell siphons are very useful, but can also be
use: http://www.youtube.com/watch?v=7S- frustrating. I have had several issues with
d6MPvkaU&src_vid=oLwTdpTIXd8&featur- bell siphons in the past, and I created a list
e=iv&annotation_id=annotation_254067 of what to consider when troubleshooting a
bell siphon:
Bell Siphon
Problem 1:
(Top) Photos of the bell siphon. (Middle) Photo of
The bell siphon will not start siphoning
Our concrete ring aquaponics system has
the pump pipe. (Bottom) Overview photo of the
some technical parts. For example, we use • Is your flow rate high enough? If it is not Concrete Ring System.
a bell siphon, both to provide adequate high enough, the water will just drain and
moisture for the growing medium and not start the suction process.
restriction issues. After a system runs for a
plants in the medium, and to ensure there
• Are the bell and standpipe level? Generally while, fish solids can stick to the sides of
is oxygen in the root zone. Also, by allowing
the more level your standpipe and bell are, the pipe, restricting flow. Typically in this
air to reach the lower parts of the concrete
the fewer issues you will have. If the bell case you will need to clean out your pipes
ring, we discourage anaerobic bacteria from does not stand up straight, use a string or or replace the pipes coming from your water
growing and causing issues in our system. other mechanism to help secure it. pump with bigger pipes.
Here is a great blog to help you understand
• If your bell siphon has been working for • Take out the bell and see if there are any
bell siphons and their benefits over a flood
a couple of months and suddenly stops roots growing into the bell siphon, which will
and drain design (http://freshfarmct.org/tag/
working, you probably have some flow restrict water flow into the siphon.
siphons/). Here is a link to a great video that
4
. . . . . . .
Problem 2: In an aquaponics system, sun protec- located, contains a healthy population of
The bell siphon will not shut off tion also benefits the Nitrosomonas and guppies for mosquito control, as well as a
Nitrobacter bacteria, which are extremely covering of water ferns. The latter provide
• Typically this means that there is too much
sensitive to sunlight. In addition to a shade food for the guppies to eat, help clarify our
water flow. You should always have a valve
cloth over the entire system, we also use water, and are an excellent protein source,
installed on the pipes coming from your
shade cloth to cover the bottom rings of the if you are interested in making your own fish
water pump, to control water flow through
unit. food (See EAN #20 for more information
the system.
about the use of water fern).]
• I have known some rock systems to have
Bottom Flow
water-channeling issues. This results in the
Drains
bell siphon turning on and off rapidly. If you
We raise catfish in the two bottom outer
use gravel that is too small, fish excrement
rings of our system. These two rings are We installed drains in all our concrete rings.
will stick to the rock and create localized
connected to the center ring, where the These are necessary when we have to do
channeling. One solution is to clean your
rocks. A better solution is to replace your pump is located, by 2-inch PVC pipes that any type of “deep cleaning.” We use 1-inch
rocks with bigger rocks. have been cemented into the walls of the PVC pipes with valves that drain into a
concrete rings. 2-inch PVC pipes allow nearby area. If you install similar drains, I
the water to flow through the system unre- suggest that you have them drain into an
Water Pump
stricted. We also have a porous cover over area where you can collect the water. This
For a five-ring concrete ring system like the 2-inch pipe opening, to keep our catfish water is high in nitrate and can be used on a
ours, you can use a water pump that is segregated to the outside tanks. Because garden as a natural liquid fertilizer.
between 35 and 50 watts. A 35-watt pump the center ring is open to the air, it is impor-
can provide enough flow for the bell siphon tant to have some type of mosquito control; Filters
(1 inch stand pipe) in the system to work, in our case, we use guppies that eat
but if there is anything restricting water flow, mosquito larvae. We allow the guppies to Since our system is a rock bed system,
you will start to have issues with the siphon. swim from ring to ring. [Editors’ note: in the filters are not totally necessary. However,
I would recommend using a 50-watt pump system at the ECHO Asia Impact Center, for our system we do use a very small filter.
for a five-ring system. When you connect our “sump” ring, i.e. where our pump is We cut off the bottom of a 4-inch planting
your pump to the system, make sure you cup, then placed an easily-removable
use PVC pipes bigger than ½ inch in diam- sponge-like filter material inside. We placed
eter. The ½-inch pipe will have issues with the filter under the water inlet in the grow
fish excrement sticking to the sides of the bed, where it catches excrement solids and
pipes, restricting flow over time. I would reduces splashing from incoming water,
also advise against gluing the PVC that thus reducing algae growth. We wash
connects the pump to the top of the unit. the filter daily, to take some of the excess
If you use glue and then have any issues excrement away from the system. Too
or want to reorganize your setup, you will much excrement may cause your rock to fill
not be able to change anything without up with solids, which will block water from
rebuilding the system. Currently, our pump flowing to all parts of the grow bed, thus
runs 24 hours a day, seven days a week, creating channeling issues. (Author’s note:
but you can use a timer if you are working most water pumps bought at fish shops
with catfish (because they don’t need will come with a filter inside of them. In my
dissolved oxygen). opinion, the filter should be taken out. If left
in, it can easily fill up with excrement and
the pump will not work as well, thus causing
Sun Protection
your bell siphon not to work. The filter can
Some type of shade is important for this be taken out and even used in the small
concrete ring system. If the unit is in direct filter mentioned above.)
sunlight all day, the water will get too hot
and cause the plants to wither. During the Cleaning
hot season here in Thailand, most days
easily reach over 95°F (35°C), which is The amount of cleaning an aquaponics
challenging for plants and fish in an aqua- system will need depends on the type
ponics system. We constructed a frame of system. If you are using filters in your
from bamboo and hung a shade cloth system, you typically won’t have to clean
above the plants to protect them from the your system for a couple years. Our
sun, but most days during our hot season concrete system has to be cleaned about
in Thailand, it was still too hot and they four times a year. In our system, we
wilted during the day. However, they usually currently have about 20 adult catfish that
perked back up at night when it started to we feed 50 grams of food every day; if you
cool a bit. If you live in a country with similar are giving more than that, you may need to
very hot temperatures, I suggest building (Top) Photos of the water pump and piping from clean your system more often, depending
the unit in an area that is shaded during part the pump to the grow beds. (Bottom) Photos of on the amount of solid fish excrement in
of the afternoon. the drain system. the system. Cleaning the system is not diffi-
5
Asia Notes Issue 22 . . . . . . .
cult, if you have drains installed. Be sure As we learned earlier, in an aquaponics system drastically, because aquaponics
to move your fish to a temporary tank or system, plants help fish and fish help plants. systems are very susceptible to swings in
bucket before cleaning your system. When There should be an equilibrium between the pH.
it is time to clean, just open the drains. After number of fish you have and the number of
running the unit for some time, the bottom plants you have. Aquaponics is all about
Costs
rings will fill up with fish waste. When balance, so if you have a lot of fish, then you
cleaning your system, make sure you stir should have a lot of vegetables (or more The cost of creating an aquaponics system
up the fish waste so it is suspended in the filters). That said, in my experience, the will depend on the design of your system,
water that is drained out of the system. real issue is not how many fish you have, the cost of materials, and the cost and
but how much you feed them. When you usage of electricity, fish, and fish feed in
pH Control first start your system, I would recommend your area. To give an idea of some of the
testing your system for ammonia, nitrite, affiliated costs, here is a table showing
Typical aquaponics systems usually have and nitrate. Test kits for ammonia, nitrite, construction costs for two different cement
a pH range between 6 and 8. Using any and nitrate can usually be found at most ring systems created in Northern Thailand.
type of concrete will cause the pH in your fish shops. If you see that your ammonia or
system to change drastically, potentially nitrite has spiked to over 1ppm, then simply
creating issues that could be detrimental stop feeding your fish for a couple days (fish
to the health of your fish and plants. This can live for several days without food).
problem can be solved in a couple of ways.
The amount of feed you use will depend on
We use coal tar epoxy to paint the inside of
the purpose of your system. For example, if
our concrete rings (discussed above). This
you are more interested in harvesting plants
is expensive to use, but you only need it for
than harvesting fish, you won’t have to feed
one application. If you prefer not to use coal
your fish very much everyday. You will
tar epoxy, local Thais instead will cut up the
just need to feed the fish enough to have
trunk of a banana tree, put it in the concrete
a healthy amount of nitrate in the system.
ring with water and let it sit for two weeks,
Here is a great article if you want to learn
which will neutralize the pH. This is a very Double-Sided Unit
more about feeding ratios and general
successful method of neutralizing pH, but
guidelines of aquaponics: http://aqua- Materials Cost (THB)
we used coal tar epoxy instead because we
did not want to wait two weeks. ponics.com/media/docs/articles/Ten-Guide- Concrete rings (x5) 1000
lines-for-Aquaponics.pdf
6 inch PVC (for bell siphon 400
Getting Your System up and guard)
Safe Ways to Test Additives
Running 2 inch PVC 200
An aquaponics system does not use soil. 2 inch PVC caps (x2) 60
When you first start your system I would
While there are some benefits to this,
suggest using only about 10 fish. As 1/2 inch PVC 200
including a cleaner harvest and no need
discussed earlier, the bacteria groups to till land, there are also some disadvan- 1 inch PVC 200
that convert ammonia to nitrite and nitrite
tages. One major disadvantage of aqua- Rock media* (per 80 cm3 400
to nitrate are extremely important for a
ponics is that some minerals that are natu- side) (x2)
successful aquaponics system. These
rally present in soil will not be in the water
bacteria groups occur naturally in water, Water pump (35 watt) 250
of the system. For example, iron is needed
but develop slowly. The older your system
by most plants. It is not naturally found in Concrete 300
is, the better it will begin to work, because
an aquaponics unit, because the fish do not Plastic chicken wire 100
there will be more bacteria to create the
provide iron to the system. You will have to
nitrate you need. Your system may not be 1 inch PVC elbows (x4) 100
buy the appropriate type (usually chelated
able to handle more than 10 fish in the iron) and add it to the unit. 1/2 inch PVC tee, 2 valves, 100
beginning. After a month or so, you can
hose adapter and elbow
start raising more fish.
Any type of additive or pest control used
Zipties 60
in an aquaponics system must be totally
As far as what to grow, I suggest starting with Paint** 400
organic, or your fish and/or plants may die.
a vegetable that is easy to grow and does
So, how do we know what we can put into Catfish weighed
not demand a lot of nutrients. Remember,
younger systems will not contain as much the system? There is a way to test if what TOTAL COST 3770 =
you hope to add is safe. Place a few of
good bacteria as an older system, and $115 USD
your fish in a container separate from your
thus will have fewer available nutrients. *Can use brick instead at 3 baht a piece
system, and connect it with an air pump.
For systems that are started in Thailand, **May use banana stalks instead of paint to
Then add half the concentration of the addi-
I always suggest to grow morning glories, balance pH, but takes 2 weeks
tive you wish to have in your system. Leave
since this vegetable seems to be able to
the fish in the tank for five or more days.
grow anywhere. After about a month, you All prices are dependent on how and where
should be able to grow more nutrient-de- If they survive, add double the amount of you buy materials. All PVC is estimated based
the additive. If the fish are still alive a week on a 4 meter length price. Does not include
manding vegetables, such as tomatoes.
later, the additive is safe to use. Do not add false bottom.
anything that will change the pH of your
6
. . . . . . .
Lessons Learned from Cement Ring Aquaponics
Systems in Northern Thailand
by Scott Breaden
[Editor’s Note: Scott Breaden has lived cm high). These hollow rings are stacked
in Northern Thailand for eight years. He on top of each either to form in-ground
came here with a rich background in cross- septic tanks, or stacked on top of each
cultural ministry, project management, and other to make above-ground water storage
development in Australasia and Africa. For and water filters. The bottom rings have a
the past six years, he has enjoyed exper- cement base and are commonly used for
Single Unit imenting with backyard gardening and raised garden beds, ornamental ponds,
Materials Cost (THB) aquaponics in Chiang Mai, where he lives and raising frogs and/or catfish. In addi-
with his wife and son.] tion to the cement rings, blue PVC pipes
Concrete rings (x3) 600
and fittings of many sizes are common and
6 inch PVC (for bell siphon 400 cheap. Small 220-volt aquarium pumps are
The Beginning
guard) also easily available (in the city at least)
2 inch PVC 200 Around five years ago, after reading online and are commonly used for fountains and
2 inch PVC cap 30 about aquaponics, a friend wanted to try a in small water features for homes, restau-
small-scale system in his urban backyard (a rants and gardens. Ideal medium (such as
1/2 inch PVC 200 rental property) in Chiang Mai. I had some uniform round rocks around 1-2 cm in diam-
1 inch PVC 200 experience working with a larger system eter) is harder to find, but normal crushed
Rock media* (per 80 cm3 side) 200 and was interested in trying a small-scale, rock for use in concrete is cheap and easily
low-cost system that would be portable available.
Water pump (35 watt) 250
and that could be used as a demonstra-
Concrete 300 tion/training model. Unlike today, in which Putting it together (Figure 1)
Plastic chicken wire 100 a great deal of information can be found
online (especially in the form of YouTube After materials had been collected (we
1 inch PVC elbows (x2) 50
videos), very little free information was used 1 m cement rings with floors, a small
Black or green hose 50 available on the design, setup, and main- pump, gravel of 0.5-0.75 cm diameter, and
Zipties 60 tenance of small-scale systems. So every- PVC fittings), our system was assembled
thing we did during that first build-out was in less than three hours and was test run
Paint** 200
experimental. without fish the next day, after the cement
Catfish weighed had dried. Then we stocked the system
TOTAL COST 2840 = with 30 cheap and readily-available catfish
Materials
$87 USD fry (people growing catfish alone in cement
*Can use brick instead at 3 baht a piece Here in Northern Thailand, many back- rings in Northern Thailand sometimes
**May use banana stalks instead of paint to yard cement industries make cement rings stock up to 50 per ring). Locally, catfish are
balance pH, but takes 2 weeks (either 80 cm or 1 meter in diameter, and 40 usually raised in cement rings in low quality
All prices are dependent on how and where
you buy materials. All PVC is estimated based
on a 4 meter length price. Does not include
false bottom.
Conclusion
Aquaponics is a wonderful new technology
that can be customized in many different
ways. However, a successful aquaponics
system will require daily management and
basic knowledge of water chemistry. It will
also involve a good deal of trial and error.
As you experiment with aquaponics, you
will tailor your system to fit your specific
needs.
The world of aquaponics is new, but growing
fast. Setting up a smaller unit is a great
first step into learning about aquaponics.
Our concrete ring system design provides
an excellent and cheap opportunity for
someone to try their hand at aquaponics! Figure 1. Scott’s first cement ring system. Illustrated by Scott.
7
Asia Notes Issue 22 . . . . . . .
water, so there was a low risk of having fish process. The final system made a very good catfish in cement rings, so adding the pump
die if we made mistakes. Thai herb garden, with perennial plantings and gravel bed would just be adding to an
of lemongrass (Cymbopogon citratus), birds already existing system.
It took more than a month to get the plants eye chilies (Capsicum frutescens), basil
growing well. While the fish were still finger- (Ocimum basilicum), pandanas (Pandanus
The Bigger Picture
lings, our system was easy to manage, but amaryllifolius), ginger (Zingiber officinale),
as the fish grew bigger, the small aquarium galangal (Alpinia galanga), edible ferns I personally think that small aquaponics
pump struggled with too many fish waste (Diplazium esculentum), and morning glory systems are more difficult to run than larger
solids and needed daily cleaning. [Editors’ (Impomoea aquatica). During the cool systems (larger than 1000 L), and I warn
Note: as mentioned in the previous article, season, I also grew tomatoes, lettuce, bok people that things can go wrong quickly in
the build-up of fish excrement and solids choi, strawberries, and other leafy greens. these small systems. But a small system
can reduce the water flow and cause prob- Overall, the system didn’t really produce like the one I have outlined is great to show
lems in aquaponics systems]. We tried large quantities of fish or food, but for me people the principles and parts of an aqua-
many things to keep the flow rate high there was benefit even in producing a small ponics system (i.e. it demonstrates how
and the pump clean (homemade filters, for amount of fresh, chemical-free food. I found various siphons, pumps, etc. work, and
example), but the cheap pump remained the this aspect was also the greatest point of shows the relationship between fish, nitri-
weak link in the system. The small system interest to neighbors and visitors. fying bacteria and healthy plants; it can also
worked well, although it would be a stretch
make a very nice water feature on a prop-
to say that it was easy to operate. But it
Looking Back erty). But a small system doesn’t neces-
met our goals at the time of: 1) being cheap
sarily model food production, because it
(under $ 40 USD) and 2) demonstrating that
Today, if someone were to ask me to help isn’t big enough to show how to produce
the principles of aquaponics could work on
build a small system on their urban rental larger quantities (or support larger projects
a small-scale.
property, would I use cement rings? The such as large childrens’ homes) of either
easy answer is yes, but I would not use vegetables or marketable fish.
Lessons Learned (Figure 2) the large 1 m rings. Today more options
exist in terms of materials and designs A larger scale system has additional chal-
With the cement rings, pipes are easy to (see Figure 3 for a prototype that I would lenges. Besides keeping the fish-vegetable
add and changes in design are straightfor- like to try sometime). Something lighter system running in equilibrium, someone
ward. However, the rings are very heavy and more easily moveable (than the 1 m running a large scale system also needs
and difficult to move or rearrange, as I rings) is generally more appropriate for an to source and store seeds; germinate
found when my friend moved countries and urban setting. I think a larger cement ring and transplant vegetables; and harvest,
I moved the system to my own backyard. design could be appropriate for rural areas, process, and market the fish and produce.
I did not like the idea of checking/cleaning since many people in rural areas (at least The complexity of all these parts working
the pump daily, so I changed the design and in Northern Thailand) know how to join the together is more easily appreciated when
added an extra ring to act as a sump tank, cement rings together and add PVC pipes. seeing a larger system. However, for home
which helped to collect the solids and keep Four or five people could drop in and give consumers, a small system is a great
the pump clean. As a result, I only needed a hand to lift or shift the rings without any starting place for learning the principles of
to check and clean the pump once a month trouble. Also, the issue of weight and perma- food and fish production, and it can easily
(Figure 2). I also stocked it with 15 catfish nence would not be as much of a problem be ramped up.
instead of the 30 that I started with initially, in a rural setting as in an urban area. And
and I planted many perennials and water- finally, many rural people in Northern Thai- When I made my own backyard aquaponics
loving plants to help in the water filtration land have had experience with raising system, I constantly thought about how I
(left) Figure 2. Scott’s modified cement ring system. (right) Figure 3. Plans for a future prototype aquaponics system. Both ilustrated by Scott.
8
. . . . . . .
could make it simpler and how I could make Selections From the ECHO Asia Seed Bank
it work in the cheapest, easiest manner. I
came from a background in large-scale
Two plants of merit that our seed bank Chia seeds yield 25-30% extractable oil
extensive agriculture, with no experience
stocks include Chia and Mung bean. As a which is rich in essential fatty acids. It
or knowledge of highly intensive small-
registered Active Development Worker on is one of the highest known sources of
scale systems. Over time, each of my
ECHOcommunity.org, you can receive up Omega-3 fatty acids. Seeds can be added
aquaponics systems have become more
to 10 free packets of seed each year. In to any meal or drink and can be digested
complex, and this increase in complexity
exchange for seeds, we ask that you fill out without breaking the seed coat. The widely
has been rewarded with a better product or
a crop evaluation form, which you can find acclaimed health benefits of Chia can be
more produce. I have also found that the
here. For more information about our seeds, attributed to its overall high nutrient content:
more energy and time I put into improving
see our current 2014 Seed Bank Catalog, high in soluble fiber, 20-23% protein, rich in
the design, the more satisfaction I get from
and also be sure to note that we currently antioxidants and minerals. Seeds soaked
managing it.
have 28 new Seed Fact Sheets as part of in water will dissolve to create a gel that
I now have the capacity to produce food for our Online Seed Store, which provide more can be used in other cooking and mixed in
my own family in a satisfying way. I am no in-depth information about the crop, nutri- juices. Leaves can be steeped to make tea
longer afraid of producing food intensively; I tional and culinary values, the care and used for a myriad of health problems.
enjoy the complexity of the system and see culture of the crop, and how to overcome
it as a positive attribute, because it opens any potential issues (pest, disease, growing
doors to learning and to new ways of doing period) the crop may have. We hope that
things. With aquaponics, you can start you find these fact sheets to be of great use!
simple, and as your knowledge increases
(about best practices and how to best main-
tain the system), you can grow and expand
your system in many different ways, being
rewarded for your creativity (i.e. thought/
design is rewarded with tangible outputs).
As an unforeseen side benefit of creating
this system, I have met many people,
and have built relationships with people
Mung Bean/ถั่วเขียว Vigna radiata
I would not have known otherwise, which
has made life so much richer and deeper.
“Burmese Green” Variety: Day-neutral,
My aquaponics system has been a great
bush variety. New to ECHO Asia. Green
talking point with my neighbors, all of whom
seed.
value healthy food and see my system as
a source of love/care in the way it provides “Lao” Variety: Day-neutral, bush variety;
good, healthy food to the family. approximately 60 days from flowering to
seed. Green seed.
Description:
Mung bean is an early-maturing bush/
Chia/เชีย Salvia hispanica slightly vining legume, high yielding and
widely adaptable. It is used throughout Asia
“Chiang Mai” Variety: Multicolored seeds, as a food legume, for flour, in desserts and
from white to brown to grey, come from sprouted for use in other dishes. It has a
plants naturalized in Northern Thailand. protein content of approximately 25%.
Mung bean is cultivated most extensively in
Photos of Description the India-Burma-Thailand region of South-
Scott’s back- east Asia but found in countries such as
yard aquapon- Chia is an annual, herbaceous plant in the Iran, Pakistan, Vietnam and China as well.
ics systems. mint family growing to about 1.5 meters
Photo (approx. 5 feet) in height. It originates Mung bean is a short season crop requiring
credit: Scott from Central America, where it has been 60 to 90 days from planting to maturity.
Breaden. grown primarily for its tiny but highly nutri- Grows mainly within 20-40° C (68-104°F)
tious seeds, for thousands of years. Chia and up to 2000 m (6,562 ft.) in the tropics.
is best planted towards the end of the rainy Grows well in areas with average rainfall of
season, with the harvest of mature seeds 600-1000 mm (24-39 in.) but it can survive
taking place approximately four months with less precipitation. Generally grows well
later. Too much moisture during seed- on warm, sandy or otherwise loose soils but
setting and maturity can lead to harmful prefers well-drained loams or sandy loams
mold and bacteria growth on the seeds. with a soil pH range of 6.2–7.2.
9
Asia Notes Issue 22 . . . . . . .
Book Review: Edible Leaves of the Tropics were published decades ago. The authors
provide helpful advice in that they recom-
Reviewed by Craig Soderberg
mend cooking the vegetables because
cooking reduces bacterial and fungal
[Editor’s Note: Reprinted with permission from The spicy shoots of ginger (consisting of
contaminants, tends to wash off any pesti-
Appropriate Technology and Craig Soderberg. young leaves folded around each other) are
cides, and changes the nature of some
Edible Leaves of the Tropics is carried by edible. Leaves of okra, carrots, radishes,
nutrients (p. x).
ECHO Asia, as well as ECHO in Ft. Myers, and eggplant are also all edible. Many
Florida, and many of the plants highlighted in fruit trees have edible leaves as well. The book did have a few weaknesses. One
the book are carried by ECHO Asia or can be
For example, the leaves of mangoes, weakness was that the book had no glos-
sourced from our network partners.]
ambarella, durian, soursop, bignay, goose- sary. A glossary would have been helpful for
berry, papayas, coffee can all be eaten. those of us who are not experts in agricul-
Edible Leaves of the Tropics, Third Edition,
ture. For example, the word ‘crucifers’ was
by Franklin W. Martin, Ruth M. Ruberte,
Chapter four lists some common weeds with
used on the first page of the first chapter.
and Laura S. Meitzner.
edible green leaves, including moonflower,
But many readers may not know that cruci-
mustard, butterfly pea, S.macrocarpon. But
Published by Educational Concerns for fers are vegetables of the family Brassi-
the reader is cautioned that many of these
Hunger Organization, Inc. 1998 caceae (also called Cruciferae).
plants, when eaten excessively, can be
ISBN: 0-9653360-1-8 poisonous. The book spoke of drying green leaves and
preserving them as powder. But no instruc-
Chapter five lists tropical trees with edible
To purchase this book or for tions were given for this practice and no
leaves including coral trees, dwarf bucare,
more information contact: reference was given for those of us who
(p.47), G.gnemon trees, Pisonia alba
[email protected]; would like to know how to do this (p.1).
(nyctaginaceac) (tree lettuce), neem,
http://www.echonet.org However, Motis and Berkelaar (2012) did
moringa.
have a short overview of this topic.
Chapter Overview Chapter six lists various tropical leaves
Also many of the plants mentioned in the
used as spices. In fact, 52 tropical spices
book did not have corresponding photos
This book contains ten chapters: (1) the
are listed in table 2 and 20 plant leaves used
or sketches or at least did not mention
place of green leaves in the diet, (2) the
in tea are listed in table 3 of this chaper.
where to find those corresponding photos
principal edible green leaf herbs of the
But the chief spices of the tropics are not
or sketches.
tropics, (3) some vegetables, fruits, and
from the leaves, but from other plant parts,
ornamental plants with edible leaves, (4)
as with pepper, cloves, ginger, cinnamon, Most of the readers of this book would
common weeds with edible green leaves,
allspice, vanilla, chili peppers, cardamon, probably like to know where to obtain seeds
(5) tropical trees with edible green leaves,
and nutmeg. for the plants mentioned in the book. The
(6) tropical leaves as spices and teas, (7)
book did have a section for seed sources
temperate zone green leaves in the tropics, Chapter seven provides some information
but most of the companies listed were not
(8) lettuce in the tropics, (9) tropical leaves about temperate zone green leaves in the
located in the tropics (p. 151). After this
that are poisonous, (10) culture and care of tropics. The chapter primarily describes
current reviewer contacted many of them
green-leaved vegetables. different types of cabbages but it also
asking for certain seeds listed in this book,
describes chicory, endive, swiss chard,
the seed companies said that they did
Chapter one contains a helpful list of other
beet greens, celery, and a few miscella-
not carry those seeds since there are not
books with information on edible leaves.
neous species.
selling tropical seeds. But this is not a short-
Unfortunately many of these books are
coming of the book. This is a shortcoming of
hard to find because they were not recently Chapter eight discusses different types of
the seed distribution system in the tropics.
published. For example, A Dictionary of the lettuce that can be grown in the tropics.
Economic Products of the Malay Peninsula
However, overall this book is recommended
(Burkill 1935) was published in 1935 and Chapter nine discusses tropical leaves that
for farmers, development workers, surviv-
therefore difficult to obtain. are poisonous.
alists, and anyone else wanting to learn
how to plant and eat what they plant in the
Chapter two was helpful in that it lists many Chapter ten discusses the culture and care
tropics.
edible plants which are perennial (i.e. can of green-leafed vegetables such as climate,
grow for several years) (i.e. Xanthosoma moisture, soils, fertilization, soil prepara-
brasiliense, Basella alba a.k.a malabar tion, care and harvest. References
spinach, Gynura crepioides (okinawa
spinach), Ipomoea batatas (sweet potato), The book ends with 56 helpful photos and Burkill, H.L. 1935. A Dictionary of the
Ipomoea aquatica (kangkon, water spinach, illustrations of some of the plants mentioned Economic Products of the Malay Penin-
Manihot esculenta (cassava), Sauropus in the book. sula. Crown Agents for the Colonies,
androgynus (katuk), sauropus, Hibiscus London. 2402. Pp.
sabdariffa (roselle). Strengths and weaknesses of
Motis, Timothy N. and Dawn R. Berkelaar.
the book
Chapter three mentions which vegetables 2012. Agricultural options for the poor:
and fruits have edible leaves. For example, This book was a helpful resource which is A handbook for those who seek to serve
the young developing leaves of corn are readily available to the public. Many similar them. Fort Meyers, FL: Echo. p. 175.
edible. Leaves of young onions are edible. books are now out of print because they
10
. . . . . . .