The space required for a circular tank is larger than that required for rectangular (Figure 19 ) because of
its round edges. This could be a problem when we have very little space to use for the system.
This shape is mostly used in home aquariums but is usually limited to that. The main problem are the
non-flow zones or low water exchange in the corners. Because of its shape and the water flowing in one
direction, the corners of the tank will get a little or no flow of fresh water .This means that they would
be dark spots. A mentioned earlier this is a big disadvantage and might become problematic for the
ecological balance.
SPACE REQUIRED^ Stable^ Easy to clean^ Water exchange^
Round Tank 1000 l Yes Yes High
Rectangular Tank 785 l No No Low
*Assuming 1m high of tank and radius 0.5 m for round tank, 1 m sides for rectangular
Table 3. Comparison of Rectangular and Round Tanks
The Table 3 below shows the two different types of tanks and advantages and disadvantages related to
usage and maintenance. There are several types of materials used to build water tanks. We can
mention, concrete, metal, fiberglass and polyethylene (plastic) (WILTON, 2001). Since in our project we
want a water tank that will host fish, the metal and concrete tanks are excluded from the design
because their performance is low building a healthy environment for the fish. The materials they are
composed are usually toxic for the living organisms. The most common material and appropriate used
for the fish tank are Fiberglass and Polyethylene .These two materials are proven to be the safest and
cheapest (Lennard, 2008).The advantage of the fiberglass material is that they are offered in any shape
and size, but this comes with a higher cost. The opposite happens with polyethylene or plastic tank.
They are cheaper but it is very hard to have them in custom size since the production of a single mold
for our needs is very expensive for the company. The fiberglass is very strong and is easy to repair
compared to plastic .If the polyethylene tank shows signs of cracks the whole tank should be replaced. It
also deforms easy compared to the fiberglass. This disadvantage can be improved by reinforcing the
base and building them with a higher quality of material.
The differences between them are shown in the Table 4 below.
Custom seize^ deformation^ Easy to repair^ Easy to clean^ Cost^
Fiberglass Yes No Yes Yes 17.5 $/g
Polyethylene No Yes No Yes 2.6 $/g
Table 4. Comparison of different tank materials
In conclusion the best tank for our system is the round tank because it has more advantages in long and
short term than its counterpart. It self-cleans, it is very stable and has high water exchange .For the
material the fiberglass is the best option because it’s easy to repair and we can have every shape we
need for our system. It costs more than polyethylene but in long term it is worth it.
2.3.2.2 Piping
Piping is the other major component of the system as it is the backbone of the whole drainage system
and the water circulation. Pipes are usually made by two materials, copper and PVC. The PVC pipes are
the most common pipes used in aquaponic, from the smallest to commercial systems. (Research, 2010)