Lights
If it says “grow light,” “plant light,” “full spectrum light” or “daylight spectrum” it will work for indoor
plant growing.
Grow beds (biggest challenge in my opinion) / Fish tank / Ratios
Grow Beds – Water weighs 8.34 lbs. per gallon, or 1 kg per liter. Expanded clay media weighs
approximately 1 lb. (450 g) per liter, and gravel can weigh more than twice that. Combine this with the
weight of the plants, the force of water continuously filling and draining, and the expanding pressure of
root growth and you have tremendous lateral strain on your containers. Be sure to select containers, the
materials for your bed, and tank accordingly. Avoid using hydroponics grow beds and nutrient reservoirs
as aquaponic grow beds. They are typically made with a thin material and were never meant to hold 12
inches (30 cm) of rock media. Avoid plastic storage containers too, unless you secure them with a
support strap or frame. Again, you will find they are too thin and will not stand up to the weight and
other forces that strain an aquaponics container.
You must put red composting worms in your grow bed. Adding 0.2 pounds should be good.
Aquaponic grow bed zones.
1. The first zone is about 2 inches deep and is called the light penetration zone/the dry zone.
Evaporation from the bed is minimized by the dry zone, and the dry zone protects the plants
from collar rot, and protects algae from forming on the surface of the grow bed.
2. The second zone is about 6-8 inches deep and is called the root zone. This is the zone where the
water will drain away completely during the flood drain cycle. This is also the zone where most
of the roots will be.
3. The third zone is about 2 inches deep and is called the solid collection and the mineralization
zone. This is the bottom two inches of the grow bed and fish waste solids and worm casting are
finally collected here.
The amount of grow bed space you have will govern the size of your fish tank (or vice versa for us).
Here’s why. The plant’s need the fish waste to thrive. The bigger the grow bed space, the more plants,
and thus more fish waste is required for the system. Simplified you need enough fish to support your
plants. The recommended beginning grow bed to fish tank ration is approximately 1:1. The volume of
the fish tank should equal the volume of the grow bed. The ration can also be thought of in gallons per
cubic foot. For 7.5 gallons of fish tank there should be one cubic foot of grow bed (or 1000 L to every
cubic meter). For example we have a 35 gallon fish tank, which will be able to support 4.67 cubic feet of
grow bed. Furthermore we want 10 to 12 inches of media (rocks), in terms of height, in the grow bed.
Take this into account when finding the correct grow bed. If you choose to use the current grow beds
available you must reinforce them, because they are currently not strong enough to handle the lateral
strain the system puts on them.
The higher the protein content in the feed, the more waste a pound of fish produces.
The fish tank should be stocked with about 1 lb. of fish per 5 – 10 gallons of tank water. Since we have a
35 gallon tank we need in between 3.5 – 7 lbs. of fish.
Plumbing (The second hardest challenge)
PVC pipes should be used for the plumbing because PVC pipes are large enough for adequate water flow
without becoming clogged with solids.
Everything should be water tight. Whenever you drill a hole in your grow bed you create an opportunity
for a leak. After drilling a hole in plastic, sometimes the plastic surrounding the holes melts and creates
bumps. Try to get rid of these bumps the best you can. Then we have bulkhead fitting to create a water
tight seal that the PVC pipe can be attached to. However it is wise to make sure your system is water
tight before filling it with the media. If you find you need to fix a leak make sure you use something that
will not introduce chemicals that are unsafe for the fish or plants into the system, i.e. don’t use glue.
We currently have a pump that is more than capable of moving the correct amount of water through
the grow bed.
There should be a drainage system that constantly drains water that is about 2 inches above the bottom
of the grow bed this will establish your solid collection and the mineralization zone. Than there should
be another drainage system that drains water 2 inches below the top of the rock media, this will
establish your root zone and light penetration zone/the dry zone.
Now the hard part. The first drainage system located 2 inches above the bottom of the grow bed should
drain at a relatively slow rate. It needs to drain fast enough so that when the pump stops flooding the
grow bed, the water located in the root zone will fully drain but it needs to drain slow enough that when
the pump is turned on the root zone becomes fully flooded. However the drainage system 2 inches
below the top of the rock media must be able to drain the system fast enough so that as new water
enters the grow bed through the pump and an equal amount is leaving the system so the dry zone is not
flooded. Make sure that when/if you choose to drill holes in the PVC pipes you use for the drainage
system you don’t make the holes big enough that the rock media can enter them. It’s best to make
multiple small holes.
Aquaponics plumbing rules of thumb
1. You should flood and then drain your media based grow beds. The draining action pulls oxygen
through the grow beds.
2. Since we are operating our system with a timer, we should run it for 15 minutes on and 45
minutes off
3. You should run the entire volume of your fish tank through your grow beds every hour if
possible.
Media
We have good rock media but before it is put into the system we should wash it. Media should not
change the pH of the system.
Water
If your water is supplied through your municipal water district it will likely have a pH above 7 and have
chlorine and chloramine in it. To remove the chlorine just run the tap water through your system for a
day or two. During this process the pH may change too (slightly). If you are adding a small amount of
water to your tank (less than 10% do not worry about the chlorine in the water). If the water contains
chloramine than the water must be filtered using activated carbon or a UV filter before filling your fish
tank. If the chemistry department has excess deionized water that would be super clutch. The pH of the
system should be kept between 6.8 and 7. If it drops to around 6.4 measures should be taken to
increase the pH. If the pH goes up there is a product called pH down for hydroponics that can be used to
lower the pH or you can also use nitric acid or phosphoric acid. Calcium hydroxide or calcium carbonate
with potassium carbonate or bicarbonate are good buffers to keep the pH in the ideal zone or fix the pH
of the system.
Do not add sodium to your system it is harmful to plants.
If possible select fish that will naturally thrive at the water temperature of your system.
Dissolved oxygen levels for fish must be above 3 ppm (parts per million) and should be above 6 ppm.
Fish
Adjust the pH and temperature of the tank to match the pH and temperature of the water your fish
were bought in.
Feeding the fish is fairly simple. They will adjust their metabolism to how much you feed them. However
you shouldn’t over feed the fish so much so that there is an excess of food in the tank when they are
done eating. You can feed your fish commercial fish feed, but make sure you know if your fish are
carnivorous or omnivorous and buy the according feed.
If the fish aren’t eating they are probably stressed, outside of their normal temperature range or don’t
have enough oxygen.
Plants
The most economical way to start plant growth is through seeds, you could germinate seeds or you can
also easily add baby plants to the media, just make sure you clean the roots completely.
Plants in an aquaponic system don’t need that much room to grow. Don’t put the plants right on top of
each other but don’t waste space on your grow bed either. You can space plants about twice as close as
you would in a dirt garden.
Cycling (THE FINAL STEP)
Cycling is basically building the bridge between your fish and the plants before you add either to the
system.
At this point everything should be set up and the plumbing should be working correctly.
The process of cycling isn’t hard but requires some know how and the full chapter (chapter 14 should be
read.) This process will require a test kit, but a chemist may already have it. This process will take 4 to 6
weeks.
After cycling you are now ready to add plants fish. It is wise to have a relatively proportional level
between your fish and your plants. If you just put seeds in the grow bed you don’t need many fish to
give them the correct amount of nutrients. If your plant bed is filled with plants than you want the
amount more fish in the tank (see ratio above).
Maintenance
Daily
1. Feed the fish
2. Check the fish tank temperature
3. Very briefly make sure the plumbing is working (If the pump turns on and water cycles through
the tank its working)
Weekly
1. Check ammonia levels
2. Check pH
3. Add water to the system if necessary
Monthly
1. Clean out pipes
2. Agitate the solid waste accumulation in the fish tank. Just move it around when the pump is on.
3. Check nitrite levels
Things you need
Thermometer
Grow light
Fish food
pH meter
Test kit for ammonia nitrite and nitrate
Things you may want to buy/have
Extra small fish tank (preferably filled with dechlorinated water
Tank heater
Supplement way to dissolve oxygen into the fish tank
Filter(really shouldn’t need this though)
Chemistry of the system picture.
Pictures of similar set ups
Links to informative or cool videos
http://www.youtube.com/watch?v=QvFKVnj3Lr4
http://www.youtube.com/watch?v=VBspR2p0YYM
http://www.youtube.com/watch?v=4DMylpQqVKI