farmed
organism.


The


most


important


water


quality


parameters

are


dissolved

oxygen,


pH,

and

metabolic
nitrogenous

wastes

(ammonia,


nitrite,


and

nitrate).


Dissolved


oxygen


(DO)


must


be

maintained


above


5

mg/L
(ppm),

below

which

supplemental


aeration

must


be

used.


In


high

-

density

RAS,


aeration

will


be

required

at


all
times,

and

depending

on

density

and

feeding


rates,


there


may


be

periods


of


time


requiring


pure


oxygen


to


be
used
(gas


or


liquid).


The


unionized


ammonia

should


be

less


than


1.0


ppm.


The


pH


should


be

between


7.5


and
8.5.

As

pH


increases,

the


percentage


of


unionized


ammonia

increases.
Cold-
blooded


organisms
Since

fish

are


cold

-

blooded

organisms,


their


growth


declines

as

temperature


declines;


therefore,


growth


in
ponds

or


flow

-

through


systems

will


decrease

or


cease

during


winter


months.

Feeding

is


commonly

suspended
when

water


temperature


is


below

60°F

(15.6°C).


In


south


Florida,


water


temperatures


in


the


winter


months


will
normally

be

conducive


to


growth


of


Hybrid


Striped

Bass,


and

feeding


should


continue


throughout


the


year.
However,

summer

temperatures


often


exceed


those


temperatures


which

allow


Hybrid


Striped

Bass


to
maintain

optimal


feed


conversion.


Research


conducted

with


Hybrid


Striped

Bass


at


various


temperatures
showed

that


when


temperatures


exceed


90°F,


the


feed


conversion


ratio


(food


consumed

converted


to


weight
gained)

decreases

greatly.


At


these


high


temperatures,


Hybrid


Striped

Bass


feed


heavily

but


do

not


efficiently
use
the


food


consumed

for


growth.


Therefore,


at


temperatures


greater


than


90°F,


a

producer


should


be
conservative
with


feed


allocation


even

though

the


fish

want


to


eat.


Research


should


be

conducted

to


evaluate
less

expensive


feed


formulations


that


provide


necessary

energy

and

essential


nutrients


but


limit


protein

thus
decreasing

feed


costs


when


water


temperatures


exceed


90°F.


Off

-

Flavor
Off
-

flavor


fish
Fish

can

be

off

-

flavor.


That


is,

they


can

have

a

musty

or


muddy


smell


and

flavor.


This


is


caused


by

chemicals
produced
by

certain


algae,


fungi,


and

bacteria

in


the


water


or


production

system.


This


condition


can

persist


as
long

as

the


organism

causing


the


off

-

flavor


is


at


a

high


density

within

the


culture


system.


Off

-

flavor


fish

must
be
purged

of


these


chemicals


by

removing

them

from

the


culture


water


long


enough


for


the


bad

tasting
chemicals

to


leave


their


bodies.


This


is


only


an

issue


when


fish

are


ready


to


be

harvested


and

sold


to


food
markets.

There

are


methods


to


dissipate


the


chemicals


causing


the


off

-

flavor


in


all


production

systems.


This
can
greatly


effect


marketing


of


your


fish.
Cage

Production
Cages

have

been


used

to


culture


many


species


of


fish,


have

been


made


of


many


materials,


and

have

been
constructed
in


many


different


shapes.
Cages

are


suspended


in


ponds,


lakes,


and

barrow

pits.


Cages


are
stocked

per


unit


of


volume


to


maintain


sufficient


water


quality.


High
densities

are


possible

in


cages

if

sufficient


water


quality


is


maintained
by
circulating


water


through


the


cage

and

back

into

the


water


body.
For
further


information


see

Cage


Production
.

Common

cage

sizes


are
square
4x4x4

and

8x8x4

foot


and

rectangular


8x4x4

or


12x4x6


foot.
The

size


of


the


mesh


material

depends


on

the


size


of


fish

to


be
cultured.

For

fingerling

Hybrid


Striped

Bass


(3–10

g),


typical


mesh