RECIRCULATION TANKS FOR SHRIMP HATCHERIES
From: steve costomiris steve11@eudoramail.com
Sent: 17 July 2001
QUESTION:
I'm in the beginning stages of hatchery development and was wondering if
anyone had an opinion on which material is preferential for recirculation
tanks - concrete or fiberglass?
Steven D. Costomiris
Los Angeles
e-mail:
steve11@eudoramail.com
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COMMENTS
1 :
Concrete tanks usually crack and leak, you can't move them easily, through tank wall fittings are difficult to install, they have to be sealed repeatedly, they are difficult to sterilize and some people think they are cheaper.
Durwood M. Dugger
BCI, Inc.
e-mail:
duggerdm@earthlink.net
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COMMENTS
2 :
You might like to consider ferrocement tanks.
In some countries they are cheaper than RCC. You can cast them in any
shape you like, round, conical, round bottom, square or whatever. You have
to be sure to place your fittings during casting, because after the tank has
cured, you cannot cut a hole in it.
There are several manuals available on the technique. I'm sure you
could find something on the web. If masons are not familiar with the
material, you have to supervise them carefully during mixing, plastering and
curing. I have made ferrocement tanks in Sri Lanka, Indonesia and
Bangladesh and they have always turned out well. If properly cast and cured,
they will never crack or leak.
Charles Angell
e-mail:
clangell@eskimo.com
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If concrete is cheaper, you can epoxy coat the concrete. We have done this
quite frequently in Ecuador, Mexico, and other countries. The final
plaster coat for the tank before the expoxy goes on, however should be made
with silica (crystal) sand and not beach sand.
The epoxy is FDA approved and the type that goes on Sea World tanks.
It does not leave a toxic residue which is biologically important
for the larvae. The finish is like one continuous ceramic tile that is
non-porous and can be disinfected.
Leland Lai
Los Angeles
e-mail: lelandlai@aquafauna.com
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COMMENTS 4:
It all depends upon the details of what you want to
do with which species and where you are located. The optimum decision for
guppies with small tanks is different than sturgeon.
Dallas E. Weaver, PhD
Scientific Hatcheries
5542 Engineer Dr.
Huntington Beach, CA 92649
USA
Tel:
714-890-0138
Fax: 714-890-3778
e-mail:
deweaver@gte.net
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COMMENTS 5:
I would recommend fibreglass; it’s much easier to
clean, maintain and modular to your recirculation circuit.
Eric Pinon
e-mail:
epinon@ecua.net.ec
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COMMENTS
6 :
Plastic liners are cost effective, easily replaceable
and eliminate the need to paint, fix chipped fiberglass, repaint with epoxy,
etc. If they are properly installed they will last for years and make for an
easily cleanable, relatively easy to repair surface.
Stephen G. Newman, PhD
e-mail:
sgnewm@aqua-in-tech.com
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COMMENTS
7 :
As Dallas said, it depends on the beast. However, if polymeric
liners (such as plastics, rubber) are used, it is important to test if they
are toxic prior to the introduction of the animals. Recently we
published on the subject of toxicity to both shrimp and nitrifying bacteria
(Horowitz, Samocha, Gandy and Horowitz. 2001. Toxicity tests to assess the
effect of a synthetic tank liner on shrimp survival and nitrification in a
recirculating superintensive production system.
Aquacultural Engineering 24(2):91-105).
Ami Horowitz
e-mail:
upahtech@yahoo.com
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COMMENTS 8:
Fiberglass can
be very competitive if you make the tanks yourself. Years ago we made 16 ft
diameter tanks from sheet material for less than $200 each. Contact me
off-line for more info.
Intensive Culture Systems
e-mail: jthomp6756@aol.com