Aquaponics Digest - Sat 09/22/01
Message 1: Re: Tilapia, striped bass or crawfish?
from "Nick"
Message 2: Aquatic Biomass Systems was Re : It's a Brand New Day,etc.
from "TGTX"
| Message 1
Subject: Re: Tilapia, striped bass or crawfish?
From: "Nick"
Date: Fri, 21 Sep 2001 22:40:35 -0700
Message
>Howdy!
>I'm a newbie, just trying to set up my first aquaponics experiment. I have
an (usually) unheated greenhouse, a couple 55 gallon food barrels, and a
green thumb. I >have some vinyl gutter, rockwool, a pump and all the
plumping stuff. But when I went to buy fish, I come up empty handed.
>I live near Seattle, and less than 2 miles from me is a grocery store
selling full grown tilapia straight from this big fish tank, but I can't
find a place that has >fingerlings, or can special order them. Same with
striped bass.
>I can go to local streams and fish out crayfish. They might like a 45 - 55
F winter instead of a 35-40 F winter. Is this a viable option? How many
would I need for >a 50 gallon system with a couple dozen lettuce plants?
>What other options do I have?
>Will
Hi Will,
We live over by Belfair, Wa and ran into the same thing/problem.
The gentleman who delivers live tilapia to the Great Wall Mall on East
Valley Highway gets them trucked in from a farm in Idaho. The truck from
Idaho has a route. I lost all names/phone numbers, but he was delivering on
Saturdays around noon time behind the mall / supermarket. The person he
gets them from said that if/when I was ready that he would send over a bag
of fingerlings and just float them on the live tanks along with some food.
If you catch up w/them, I would appreciate a phone number if you get it.
You may run into the same problem we had with no heated tank
.dead fish.
We picked up about a dozen or so, over a couple of different weekends, and
they all died. However, the trip over for them (fish) is not a good one
with about 500 in a tank about 4X4X3 with pumped oxygen so they were
stressed to begin with. Then we put them in an unheated travel tank
(cut-off plastic barrels) for the 70+ mile trip home. The last batch was a
big problem as his oxygen tanks depleted early that morning so they were
REALLY stressed when we got them.
There is a live fish dealer in/near Tacoma who gets their fingerling stock
from Eastern Wa and they will sell small numbers of various specie suitable
for cold water. I don't know if their number is still good, but here is what
I have for them:
Fingerling Supply
June, lives in Ellinsburgh, call:
253-627-7287 (phone/fax number)
Allow 1 week notice
Bullfrogs 0.85 (no legs formed yet, tadpole?)
Bluegill 1.65
Catfish 1.65
Hope this helps
.nick
| Message 2
Subject: Aquatic Biomass Systems was Re : It's a Brand New Day,etc.
From: "TGTX"
Date: Sat, 22 Sep 2001 10:06:00 -0500
----- Original Message -----
From: TGTX
Sent: Sunday, September 16, 2001 8:57 AM
Subject: It's a Brand New Day! was: Moving on Down the Road
>
> Biomass and fossil fuel combustion methods: Shucked corn as fuel for
a
> biomass source of heat. Pelletized hardwood, waste wood, or scrap lumber
>
> Methane as fuel for heat. Methane from anaerobic digestion (AD)
tanks,
> the organic material as feed stock potentially originating from excess
> sludge within an recirculation aquaculture system. I know a guy whose
> company knows all there is to know about this. The other products from AD
> can help fertigate "organic" hydroponic grow beds. I am working with
> aforesaid "Mr. AD" to do this in an integrated agriculture/aquaculture
> system on large scales. Wish us luck.
> Thanks for the positive vibrations, yeah!
> It's a Brand New Day!
To continue this long winded, impractical, inane monolog a bit further for
the sake of entertainment or torment, here are some biomass energy resources
on the web:
http://www.eren.doe.gov/consumerinfo/refbriefs/t316.html
Note that most biomass references or projects you may find focus on
switchgrass, poplar trees, willow trees, cottonwood trees, forestry/wood
waste, corn stalks
that is all I can think of right now off the top of my
head, from what I have read
I know there is more, but those seem to be
the most often cited, from what I recall.
But SWITCHING FROM SWITCHGRASS FOR THE MOMENT
.HEY, Y'ALL, LISTEN: If anyone can help me find 2 OLD publications from the
late 1970's, I would really appreciate it. They were to have been published
by the U.S. Government's National Technical Information Service. But I am at
a lost to find them.
"Sources and Systems for Aquatic Biomass as an Energy Resource" by E.H.
Wilson, et. al
and
"Cost Analysis of Algal Biomass Systems". by E. Ashare, et.al. Spring, 1978.
These reports were prepared by Dynatech R&D Company with the cooperation of
principal investigators from the Woods Hole Oceanographic Institution,
California Institue of Technology, and the University of California at
Berkley. The paper by Wilson et. al. is a compendium of the "state of the
art" (circa 1978) of larger scale aquatic plant husbandry, with an extensive
bibliography. The paper by Ashare, et. al. includes the engineering and
economics of large scale aquatic plant biomass systems including a careful
listing of the assumptions used in analysis of the baseline systems and
variations of parameters around the baseline assumptions in order to provide
a sensitivity analysis.
I found these citations in a brief report by the MIT/Marine Industry
Collegium Brief #11, entitled "The Economics and Engineering of Large-Scale
Algae Biomass Energy Systems". Here are some highlights of that MIT brief:
Photosynthetic efficiency for storing solar energy in biomass in outdoor
systems is roughly 1%, based on a biological productivity of 10 grams of ash
free organic matter/m^2/day and an assumed energy value of 5.5
kilocalories/gram.
Some useful conversion values for thinking and calculating in large scale
designs:
1 acre= 43,560 ft^2 = 4,047 m^2 = 0.4047 hectare. 1 sq.mi= 640 acres=259
hect.
1 kilocalorie = 4184 Joules = 3.958 BTU.
1BTU=1.054 Joules= 0.252 kcal=2.929X10^ -4 kw hours.
1 gm/m^2/day= 3.65 metric tons/hectare/year = 1.34 (short) tons/acre/year.
1000 cubic feet of natural gas has an energy content of about 1x10^6 BTU.
Here are some interesting notions from that brief, the robustness of which
may be questionable to a degree:
The bioengineering problem of growing mass algal culture or aquatic plants
is threefold: first, to select or breed aquatic plants whose photosynthetic
efficiency is perhaps ten percent instead of one percent; second, to provide
the nutrients and environment to support the growth rate implied by a 10%
photosynthetic efficiency; and third, to harvest and process the biomass
efficiently. The energy cost of providing nutrients and of harvesting must
be low, or the net energy production may be negative.
For example, the energy required to stir a medium, to bubble CO2 through a
medium, or to move water to and from ponds of various types may consume a
very substantial portion of the gross energy output. Separation of
microalgae, or their concentration for digestion, could also be nontrivial
from an energy viewpoint. Equipment to contain, grow, move, separate,
concentrate and digest aquatic plants represents a potential energy
investment to create (as well as to operate) a biomass system and the
"energy payback" period must be considered in determining true net operating
efficiency of the algal system.
It must be observed, the brief asserts, that from both an energy viewpoint
and from an economic viewpoint, net energy output from a massive aquatic
plant system MAY NOT BE THE BEST WAY TO ACCOUNT FOR the energetic
contributions that a plant system can make to the NET of "national energy
balance".
For example, the net energy output of protein from a plant system should not
be measured only by the energy (caloric) content of the protein product. At
present, at least 2 calories of energy are expended to CATCH one calorie of
edible fish meat (fish caught from the wild
.O.K.?). Other meats and other
protein sources are even more expensive in terms of energy cost. Thus the
caloric value of algal protein which replaces fish or other meat either
directly or indirectly may "save" several times the amount of energy
represented by the caloric value of the algal or plant protein alone.
The "savings" of the energy product of an aquatic plant system must also be
considered when determining the net effect on the "national energy balance".
Important contributions to the net "national energy balance" may be
overlooked if energy accounting does not extend beyond the boundaries of the
plant system.
The example given also applies to financial balances, or cost
considerations. Obviously, the dollar value of algae or aquatic plants
grown for protein or for refinery feedstock is going to be orders of
magnitude more valuable than just the heat value of the protein. In
addition, if an algal energy farm "consumes" sewage waste, or aquaculture
waste as in greenwater systems, which would otherwise be expensive or
"environmentally costly" to dispose of, a credit should be applied to the
energy cost and net output.
Clearly, rapid growth is a desirable parameter of a biomass system for
storing and converting energy. The faster the biomass grows, the more there
is to convert into energy. Also, faster growth implies the advantage of
less area devoted to biomass culture.
Fast growth is also important for another, less obvious reason: the more
frequently biomass can be harvested, the less carbon, nitrogen, and
phosphorus will be tied up or stored within the system. In other words,
frequent harvesting means more rapid recycling, and hence, greater
utilization of essential nutrients. This point assumes considerable
significance when one calculates the enormous nutrient requirements for
sustaing biomass growth in quantities that make large-scale energy
conversion attractive.
The productivity, p, in grams/m^2/day can be expressed as p = M x g in
which M= the total standing biomass/m^2, g= fractional growth in percent
per day. One could obtaiin, for example, 1 gram/m^2/day in many ways. Once
could have M = 100grams/m^2 and g be 1% (0.01) per unit/day - or M could be
equal to 10 grams/m^2 and the growth could be 10% (0.1) per day. A forest
of trees has a very large M and a small g.
Put in another way, if a crop of size p could be harvested daily (as may be
the case with marine algae), only 1/365 as much standing biomass (M) would
be needed as if the same crop were harvested yearly.
For microalgal systems, optimum productivity (gm/m^2/day) for present
systems seems to correspond to harvesting rates of about once per day. In
lab systems, doublings of biomass 4 to 8 times per day have been acheived,
suggesting an important direction for improving efficiency of biomass
systems.
Note also that tha high percentage growth rate (g) does not by itself assure
a high yield (p). The product of growth rate (g) and standing mass (M) must
be large.
The above assumes that the harvested part (yield) is equal to the
incremental growth. In the case of Macrocystis, the marine alga, only a
fraction of the growth (the canopy) is harvested. In summary, rapid growth
rates are important for two reasons: 1) They can minimize the area required
for growth. 2) They can minimize the standing biomass which must be managed
to start and operate the system.
Let me know if any of you can find those two NTIS papers from so long ago
and far away.
Thanks.
Ted
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