Farmer’s Weekly – 02 August 2019

E

nslin Aquaponics in

Midrand was established in

2004 by leading aquaponics

researcher Barry Enslin. When

he retired in 2015, the business

was taken over by Justin

Hess and his wife, Nikki, and

became Ichthys Aquaponics.

The couple continued much of

the research started by Enslin.

In 2017, they were joined by

Hein Oosthuizen, who became

the facility’s technical director.

The farm produces trout

and tilapia, as well as herbs,

tomatoes and baby spinach,

which are sold to local

supermarkets. The tilapia are

sold to Food Lover’s Market and

the trout to local restaurants.

The business, which employs

eight permanent staff members,

also sells aquaponics equipment

and provides advisory services.

When the Hesses purchased the

farm, it consisted of one tunnel,

which is still in use. In 2016, they

bought 1ha next to the tunnel

with the aim of expanding

the aquaponics operation.

“Aquaponics producers tend

to operate on a smaller scale,”

says Hess. “This may be because

of limited funding for capital

investments, space limitation in

urban settings, or few lucrative

sales outlets. We wanted to

challenge aquaponics norms

and the way the technologies in

aquaponics are used to create

opportunities for scaling up.

“We decided to change our

system design first to optimise

space. This allowed us to

increase production without

increasing input costs.”

NEW TUNNELS

Learning how to reduce

production costs was step

one. Once they had sufficient

experience, the couple started to

expand the business by installing

two new tunnels in 2017.

These are designed for tilapia,

which prefer warmer water.

In 2018 and 2019, the

Hesses installed five more

tunnels for trout, which

prefer cooler temperatures.

“The new tunnels are made

of plastic,” says Hess. “They

have higher roofs and roll-up

sides for ventilation, which

enables us to save money

on temperature control.”

They have also been equipped

with geothermal heating and

cooling technology to maintain

a constant temperature. Each

tunnel has four to six fish tanks.

“The new system allows

water and nutrients from the

vegetables to flow back into the

fish tank more efficiently. The

improvements we’ve made to

the system allow us to increase

production by as much as four

times over the same period.”

Another change was to move

the tanks holding the trout

outside the tunnels; this enables

them to grow more crops inside.

The farm produces Nile

tilapia (Oreochromis niloticus)

and redbreast kurper (Tilapia

rendalli). The former is indigenous

to Central and North Africa

and the Middle East. In South

Africa it has been declared a

Category 1b species, according

to the National Environmental

Fast Facts

• Ichthys aquaponics was established in 2004
  by leading aquaponics researcher Barry Enslin,
  and is now owned by Justin and Nikki Hess.


• the couple grow trout and tilapia and have
  increased the size of the operation significantly.


• they experiment to find the optimal way of
  growing both the vegetables and the fish.

TOP:

From left: Nqoby

Mkandla, Hein

Oosthuizen, Sebuki

Mmadi, Moses

Mmadi, Priscar

Sithole and Justin

Hess of Ichthys

Aquaponics.

RIGHT:

Aquaculture is the

process of growing

fish in a tank, but

the fish produce

ammonia, algae,

minerals and

other by-products

that need to

be constantly

filtered. Plants

absorb ammonia,

algae, minerals

and nitrates.

OPPOSITE PAGE

TOP:

Changing systems

has enabled Justin

and Nikki Hess to

experiment with

different growing

methods. For

example, they have

used polystyrene

for growing

spring onions as

it is superior to

gravel beds.

BOTTOM LEFT:

Basil, tomatoes,

mint, parsley and

baby spinach

are sold to local

supermarkets.

BOTTOM RIGHT:

Vertical hydroponic

growing systems.

photoS:

Siyanda SiShuba

2 august 2019 farmer’sweekly 33