Designing an Aquaponic Greenhouse for an Urban Food

Design

Simplicity

Surface

area

Cost Biofuel Stability Combination

With other

Filter

Trickling

bio filter

Yes Low High Yes High No

Fluidized

bed

No High Low No Medium Yes

Rotating

bed bio-

filter

No Low High Yes Medium No

Sources: http://www.americanaquariumproducts.com/fluidizedsandfilter.html. http://ag.arizona.edu/azaqua/ista/ISTA7/RecircWorkshop/.
http://www.aces.edu/dept/fisheries/education/documents/Bulletin9A.pdf

Table 8 : The Pros and Cons of Different Types of Bio Filters

The mechanical filtration is usually simpler and easier. We can use different filters in different parts of
the system as long as we don’t prevent the regular flow of water and they are not made by material that
is bad for the fish and plants. The mechanical filtration depends on the type of the fish tank design too.
Another important thing to notice is that most of the pumps come with mechanical filters inside.

For our system the best biological filter would be the fluidized bed because it has low cost compared
with the others. It also does not allow the overgrowth of the bacteria and it combines well with the
other filters. It is very appropriate for the seedlings and has high surface area. Mechanical filters are
open choice so we can pick them based on the pumps and their accessories.

2.3.2.6 Plant Bed Style
Bedding is a very important part of the aquaponic process. It is the part that brings all of the resources
together and leads to end production i.e. plants. Choosing an efficient means of growing the plants is
important to maximize the product output given the resources. There are two main bedding styles that
were looked at. Both bedding styles use two completely different bedding mediums. Each medium has
its strengths and weaknesses.

2.3.2.6.1 Pebble Media Bedding Style
The first one uses a pebble type of media. The material of this bedding style vary greatly. The two most
common are either clay pebble media or gravel pebble media. The media is placed in a deep tray.
Nutrient rich water is pumped in and out of the system.

The top surface is the dry region of the media. Figure 26 displays this region. The dry region offers many
important uses. Water conservation is a significant aspect to consider when a lot of water is being used
in a system. The topmost later reduces the amount of water that evaporates into the air. (Richard,
2011).

The second zone is the region that the roots occupy. This region is important because it is the part of the
system that the plants receive their nutrition from. If this part fails in the system, the plants will not
survive. This region is the part of the system where the nutrient rich water is pumped in and out of. The
cyclical movement of the water ensures that the plants receive an even amount of nutrient rich water.
When the water is periodically drained from this region, the roots are able to receive fresh air and
oxygen from the first zone. This system can also support living creatures such as worms or other
organisms that are beneficial to the plant system. (Richard, 2011).