The benefits of Duckweed/ or lack of benefits???.

[15mules]

Ok,
I have read many post, not just here but in other AP places of how to raise duckweed and how to feed duck weed etc. But to be honest I am just not convinced of the benefits. I mean I understand it is renewable and sustainable and if that is your primary reason for feeding it, then I understand. I also have read of people feeding it as a "Treat" for their fish, and there again, if that is your primary goal I understand. But economically I just do not see the benefit.
Here is the information I have gathered about duckweed. I have created averages from several different tests and studies I found, to simplify things and keep me from having to quote a bunch of different sources with fairly similar numbers.

- Duckweed can multiply twice its original amount in 16 to 24 hours, under ideal conditions.
- Duckweed has approx. 35% to 40% protein if grown under ideal conditions. (This is dry weight protein)
- Duckweed has approx 5% to 15% fiber (this is based on feeding entire plant, leaves, stems, everything)
- Duckweed is approx. 90% to 93% water (as are most aquatic plants)

Now lets do some simple math with the above numbers.

10 pounds of duckweed produced, would equal approx. 1 pound in dry weight once you remove the 90% water. This would mean for every 10 pounds of duckweed I could grow I would be producing the equivalent of 1 pound of dry feed with a protein of approx 35% to 43%.
To produce this 10 pounds, I would need to provide a container (pool, plastic tub, etc) possibly piping to and from my AP system and possibly a pump to circulate the water.
Floating catfish food in my area runs around $22.00 to $25.00 per 50# bag. That is approx .50 cents per pound, for 1 pound of fish food in the 35% to 38% protein range, basically the same as our 10 pounds of duckweed. My conclusion is; I worked for a week checking my duckweed, I invested in a container, maybe a pump and some pipe and my return on this is .50 cents worth of feed per week?? by feeding it "fresh", I am also risking spreading it to my entire system, and into places, I may not really want it! All this, for .50 cents of feed?
Now look, I am certainly no expert on Duckweed. I have never grown or fed Duckweed. I am only going by the information I have gathered in the discussions on AP forums etc. as to how people are feeding and using duckweed and by the studies I have looked up where they have done test to determine the protein content etc. for duckweed. Maybe I am totally wrong about this? Hopefully I am. I would love to find out that Duckweed is truly a FREE Tilapia feed? If some of my findings is wrong, please explain it to me and help me see the benefit of duckweed.
thanks for listening

[keith_r]

most people don't think it out, and think that they can just grow duckweed to feed their fish, and have a "zero input" system.. but they soon find that doesn't work..you need input!
i've looked up lots of info on duckweed, and for me it has it's place..
i have three 55 gallon glass tanks, one 45, two 20's and 3 tens..
in all my glass tanks,(besides sponge filters) i use duckweed to consume ammonia produced by crayfish (i've got a couple other plants in the tanks as well, not only to consume ammonia and nitrites, but as habitat for scuds crayfish and minnows), which are also an excellent supplementary fry/minnow feed by the way), and as it grows i thin out each tank every couple weeks, but basically every weekend i put several net "scoops" into the fish tank... the tilapia clean it up over night..
but my primary feed is a mix of several varieties of commercial fish food (low to high protein)..
if i was using raft tanks, i'd be concerned about mosquitos, and would populate the troughs with minnows to eat the larvae..the problem there is that the minnows will also eat the gammarus/scuds..
in the end, it's all about balance

[urbanfarmer]

[commercial feed is] basically the same as our 10 pounds of duckweed
False.


If some of my findings is wrong, please explain it to me and help me see the benefit of duckweed. thanks for listening
As you stated in a previous post (I think it was you) a few pennies difference in fish feed cost can make or break a commercial operation. Supplementing "free" duckweed for some portion of your commercial pellet feed will reduce the cost of a business owner. You are clearly focusing on the cost of the thing. There are benefits that cannot be monetized. For instance, you can buy some GMO, pesiticide laden corn for $1, let's say. You can buy the same corn, with the same protein, sugar content, etc, for $3 except this corn is not GMO, was grown without synthetic pesticides or fertilizers, and may generally be more nutritious because of trace minerals, higher content of vitamins, or whatever. Just because the protein matches up, hell even if it's the same species, it doesn't mean it's the same quality feed/food. The $1 corn is still cheaper though, sure... :twisted:

[urbanfarmer]

but they soon find that doesn't work..you need input!
I would argue that no natural system, anywhere on this Earth, requires human input to grow. I would further extend this premise to include properly designed AP systems as not needing human input (aside, perhaps, at initial construction). I have done it, the science backs it up, and it's actually a hell of a lot easier for a backyard gardener. Just food for thought... :ugeek:

[dead_sled]

I would argue that no natural system, anywhere on this Earth, requires human input to grow. I would further extend this premise to include properly designed AP systems as not needing human input (aside, perhaps, at initial construction). I have done it, the science backs it up, and it's actually a hell of a lot easier for a backyard gardener. Just food for thought... :ugeek:

I can comprehend the natural system does not need human input. I get that. The Earth was that way for millions of years. With an AP system that produces food, there is a loss of substance during harvest. How is the loss balanced without human input? The way I am imagining it, plant products and even fish are consumed out of the system. In a natural system, the creatures doing the consuming are part of the system. With AP, we are not a direct part of the system. Our waste products do not stay in the system. Please explain this to me, as I am very interested in efficiency and having a system that mirrors the natural way. :geek:

[keith_r]

but they soon find that doesn't work..you need input!
I would argue that no natural system, anywhere on this Earth, requires human input to grow. I would further extend this premise to include properly designed AP systems as not needing human input (aside, perhaps, at initial construction). I have done it, the science backs it up, and it's actually a hell of a lot easier for a backyard gardener. Just food for thought... :ugeek:

an ap system is far from natural....
i'd like to see a zero input system that you can harvest fish and veggies from and is zero maintenance? (labor is input as well, unless you work for free and don't need any calories)

i see ponds that people think are "zero input" ecosytems,, but to balance a pond the pond owner needs to input lots of energy and effort.. i really can't see an ap system working without lots of input in at least man power and some input in feed/nutrients

[15mules]

Ok, so who is feeding their fish only duckweed, how much are you raising and feeding, how much input cost do you have in producing your duckweed, what kind of growth are you seeing in your fish?

UF, I guess the point you are trying to make when you say "False" is that duckweed is natural or organic and fish feed is full of GMO corn and chemicals?? This would go back to my original argument for DW if a person is doing it because they want a self sustaining or totally organic system. I can understand that, but it does not make it economically better.
As far as an AP system being natural, it is not, it is a man made ecosystem, just like a zoo or a man made pond, without human input it would die in short order.
Comparing Aquaculture to AP to me is apples and oranges, Aquaculture is competing with cheap imorted fish and expects no secondary source of income such as produce, only fish. I would never build a AP system if I thought my primary income source would be the fish. This has been proven to not work. Several commercial AP systems I know of all say the same thing, they lose money on the fish sales. This is why they have moved away from high density stocking rates and went to low density stocking rates and focused more on plant production while maintaining minimum fish populations for proper water nutrients.
But that is really for a different thread and a different topic. I just want to see some solid information on how duckweed can be economically produced and beneficial when the time, and input cost are factored in, because I just do not see it.

[keith_r]

I don't think you'll find anyone growing tilapia on just duckweed (at least not for long)....

can i ask what "commercial" aquaponics systems you've seen mention that fish loose money?
any successful business will take some marketing..

if you grow show quality koi, you can sell a single fish for hundreds, if not thousands of dollars..
or if you raise trophy quality fish, you can sell to taxidermists for big bucks.. i know a taxidermist that sells the trout he raises for over $100 each - he's also set up aquaponic systems in high schools, the kids grow the fish out (bluegill and yellow perch), and at the end of the year, the fish go into his trophy ponds..

raise a few sturgeon and wait 10 to 15 years to harvest the caviar and make a small bundle...

around here tilapia is cheap (around $5lb).. a backyarder couldn't compete.. but yellow perch sells for $15-$16lb..
striped bass even more..

with a 12 tank setup, you could harvest once a month for specialty sales (restaurants, farmer markets etc)

so these "commercial" ap systems that are loosing money on the fish.. do you think they know the only way to make it work? or just figured out a "niche"?

[15mules]

I will send you a pm about the fish thing, so maybe we can get some more info. on duckweed here.

[urbanfarmer]

an ap system is far from natural....
Whose fault is that?



[quote="keith_r":2giosuii]but they soon find that doesn't work..you need input!
I would argue that no natural system, anywhere on this Earth, requires human input to grow. I would further extend this premise to include properly designed AP systems as not needing human input (aside, perhaps, at initial construction). I have done it, the science backs it up, and it's actually a hell of a lot easier for a backyard gardener. Just food for thought... :ugeek:

an ap system is far from natural....
i'd like to see a zero input system that you can harvest fish and veggies from and is zero maintenance? (labor is input as well, unless you work for free and don't need any calories)

i see ponds that people think are "zero input" ecosytems,, but to balance a pond the pond owner needs to input lots of energy and effort.. i really can't see an ap system working without lots of input in at least man power and some input in feed/nutrients[/quote:2giosuii]
I'm guessing you put "zero input" in quotes because it's some kind of gimmick out there? I have no idea what that is, but I don't see why you can't grow some tilapia in a pond without having a human throw food or fertilizer in there, happens all the time...

To clarify, no nutrient/food input to the system, but yes how could there be no labor? However, very little labor can be required. It depends how much you want to manage and play with the system. There will always be some labor required... who else is going to chew the food for you?? :lol:

[urbanfarmer]

Good comments dead_sled. I see you are thinking!


With AP, we are not a direct part of the system.
False. Explain why you think this must always be true? You state this as a priori knowlege, yet I would question the basis for your assumption.


Our waste products do not stay in the system.
Some waste products certainly do stay in the system, but some are removed; therefore, this statement is partially false.


How is the loss balanced without human input?
It depends. The loss of what? Carbon, hydrogen, and oxygen are the bulk of plant matter. These can come from "the air" for most AP systems, if so designed. In fact, some are. As for the rest, it depends because it's very specific to the details of the system.


:mrgreen:

[urbanfarmer]

you are trying to make when you say "False" is that duckweed is natural or organic and fish feed is full of GMO corn and chemicals??
No. Comparing the protein content as you are doing does not take into account feed digestibility nor other nutritional requirements of the fish. Where you see it says protein on the label, it does not tell you the break down of that protein. Some raw foods have enzyme inhibitors that can cause all sorts of problems in your fish if not accounted for. Some foods have toxins that, if fed in small enough quantity, are an acceptable supplement in feed, but if fed too much cause death. There's more to consider. It's a bit of a long and winding road to properly learn about... the short answer is: use duckweed to offset SOME, but NOT ALL of your feed. :mrgreen:

[urbanfarmer]

Any as a general rule of thumb: If your duckweed is growing slow, the protein content is very low. If it's growing very fast, the protein content is very high. Obviously, feeding very low protein duckweed is going to yield slow fish growth as well. Not all duckweed is created equal! :lol:

I was nice and found the info in the relevant literature... :oops:


The value of duckweed as a feed resource for
domestic animals increases with increasing crude
protein content. In studies at the University of New
England, Armidale, Australia, the crude protein
content of duckweed growing on diluted effluent from
housed pigs increased with increased water levels of
N from about 15% crude protein with trace levels of N
(1-4mg N/l) to 37% at between 10-15mg N/l. Above
60mg N/l a toxic effect was noticed perhaps due to
high levels of free ammonia in the water. Whilst few
experiments have been undertaken on the optimum
level of ammonia required, these results give a
guide-line for the levels of N to be established and
maintained in duckweed aquaculture to obtain a
consistently high crude protein level in the dry matter.

[15mules]

UF, If I understood deadsleds post correctly the idea that we are not a direct part of the system, refers to what I am assuming is the "Human" removing plants and fish from the system to consume, but our waste is not returned to the system, therefore you are removing something from the system without having an input.
As far as your explanation of the benefits of duckweed, in your opinion. I understand what you are saying, some proteins, nutrients, etc. are absorbed better by a body in different forms. I agree with that, so I think we are on the same page, as far as that is concerned. I assume and correct me if I am wrong, that your idea is that duckweed along with some other supplemental feed would make a better balanced diet for the fish and possibly promote better overall health and growth for the fish. I could also go along with that, as there is no doubt a more diversified food source would stand a better chance of meeting all of the bodies needs, than a diet based only on one nutrient source.
However, from an economical standpoint, we need to be able to put a dollar amount on the food value of duckweed. We can then figure the investment in infrastructure, time and labor to produce x amount of duckweed. This, in order to know what the feed is costing to produce, and what the benefit is as a fish food. Without being able to do this, there is no way to accurately determine the value of duckweed, as a fish food, besides anecdotal evidence.

[urbanfarmer]

UF, If I understood deadsleds post correctly the idea that we are not a direct part of the system, refers to what I am assuming is the "Human" removing plants and fish from the system to consume, but our waste is not returned to the system, therefore you are removing something from the system without having an input.
As far as your explanation of the benefits of duckweed, in your opinion. I understand what you are saying, some proteins, nutrients, etc. are absorbed better by a body in different forms. I agree with that, so I think we are on the same page, as far as that is concerned. I assume and correct me if I am wrong, that your idea is that duckweed along with some other supplemental feed would make a better balanced diet for the fish and possibly promote better overall health and growth for the fish. I could also go along with that, as there is no doubt a more diversified food source would stand a better chance of meeting all of the bodies needs, than a diet based only on one nutrient source.
However, from an economical standpoint, we need to be able to put a dollar amount on the food value of duckweed. We can then figure the investment in infrastructure, time and labor to produce x amount of duckweed. This, in order to know what the feed is costing to produce, and what the benefit is as a fish food. Without being able to do this, there is no way to accurately determine the value of duckweed, as a fish food, besides anecdotal evidence.
Proteins are made up of amino acids. Different organisms on this planet need different amounts of amino acids for optimal growth. Not all proteins are created equal in their composition of amino acids. The wrong balance or lack thereof will have a negative affect on growth. It is a false assumption to infer that all proteins are equal.


You can assume the cost of the duckweed offsets the cost of your feed and calculate the cost/benefit ratio from that. Growing duckweed can be an inexpensive venture in itself.


I just want to see some solid information on how duckweed can be economically produced and beneficial when the time, and input cost are factored in, because I just do not see it.
If it's not a good fit for you or your business, then don't include it. For some, growing duckweed on the farm can be done inexpensively. It is very cheap to grow duckweed; so, there is potential for cost savings. Hell, you can even sell it as a premium feed product. There's plenty of hobbyists out there that would pony up for some. Make sure to put ORGANIC and HEIRLOOM real big on the package! :mrgreen:

Another point, fish feed is not the same price in all parts of the world nor is it the same quality. This affects the cost/benefit ratio significantly.

[15mules]

UF thanks for your ideas and the added information on the subject of duckweed. Hopefully this information along with the other threads here on duckweed will help others decide if duckweed is worth a try for them.
Here is where I started in my thoughts on the subject of duckweed.
#1, Duckweed is a possible miracle free food source for fish, like manna from heaven according to many threads I have read in various places.
#2, Duckweed is the "devil" and will take over your AP system and spread to every nook and cranny, overtaking everything else, according to others.
Now that we have had this discussion, here are my thoughts on duckweed.
#1, Duckweed while seemingly easy to grow and relatively cheap to produce, (compared to some other fish foods), is not a miracle food that will replace all of your feed cost with a FREE food. Duckweed can however, be beneficial if feed as a supplement along with other quality fish feeds.
#2, Whether duckweed is economical or worth the time and effort and expense to grow for YOU, is going to depend on your individual situation and many local, environmental, economical, etc. circumstances.
#3, Thus far based on the limited information we have on duckweed, it would be difficult to accurately put a number on what the exact $$$ value of duckweed is.
To be quite honest, I do not have the needed time or desire to carry out such an exhaustive study to determine this exact $$$ amount of value in duckweed. This is why I was hoping to learn this information from some of you who are actively using and feeding DW. Everyone is certainly free to make their own decision, as to the benefits of duckweed in their particular AP system. What I have seen, thus far, has led me to believe, if I have the spare time to experiment with duckweed it would be worth the effort, as there is potential for some benefits.
Now having said that, I would not have high hopes going into that experiment of large $$$ gains in feed production. My best hopes in such an experiment, would be to provide a supplement that may slightly lower my feed cost, but more importantly, would provide me with healthier fish. But that is just me, you need to make up your own mind based on your unique situation.
Again UF, thank you for your informative post on the subject. As for labeling my duckweed "ORGANIC", yea I will get right on that, and wait for the USDA folks to show up, handcuffs in hand!!!!

[urbanfarmer]

#1, Duckweed while seemingly easy to grow and relatively cheap to produce, (compared to some other fish foods), is not a miracle food that will replace all of your feed cost with a FREE food. Duckweed can however, be beneficial if feed as a supplement along with other quality fish feeds.
TRUE. The "miracle food" phenomenon is simply human wonder and awe at nature. An almost microscopic organism can replicate itself in standing water with no visible input aside from the sun. This 1 lone duckweed can reproduce into millions, billions of plants that are edible and high in protein. Most plants, if first learned about, would elicit the same wonder. This is not a bad thing, it's a sign of human intelligence. :mrgreen:


#2, Whether duckweed is economical or worth the time and effort and expense to grow for YOU, is going to depend on your individual situation and many local, environmental, economical, etc. circumstances.
TRUE. This is simply a shift in your paradigm of what you thought about duckweed before and how you've learned to view the economics of a system from a for-profit business viewpoint. GREAT! :mrgreen:


#3, Thus far based on the limited information we have on duckweed, it would be difficult to accurately put a number on what the exact $$$ value of duckweed is.
To be quite honest, I do not have the needed time or desire to carry out such an exhaustive study to determine this exact $$$ amount of value in duckweed. This is why I was hoping to learn this information from some of you who are actively using and feeding DW. Everyone is certainly free to make their own decision, as to the benefits of duckweed in their particular AP system. What I have seen, thus far, has led me to believe, if I have the spare time to experiment with duckweed it would be worth the effort, as there is potential for some benefits.
Now having said that, I would not have high hopes going into that experiment of large $$$ gains in feed production. My best hopes in such an experiment, would be to provide a supplement that may slightly lower my feed cost, but more importantly, would provide me with healthier fish. But that is just me, you need to make up your own mind based on your unique situation.
Again UF, thank you for your informative post on the subject. As for labeling my duckweed "ORGANIC", yea I will get right on that, and wait for the USDA folks to show up, handcuffs in hand!!!!

I understand not having time to invest into a full investigation into duckweed. However, I think I and others here have communicated the burden of growing duckweed a little too heavy handed. Duckweed, as the name suggests, grows like a noxious weed. It knows how to survive, out compete, and gather resources from its environment without much human input. Take a party cup and fill it with water and some duckweed. Manage that cup until you can get that sucker at capacity. Make sure you can harvest 1/2 or 1/3 of it and it comes back in 2-3 days. Upgrade to a 5 gallon bucket after that. Try it indoors/outdoors. Manage these little systems when you are having a beer or whatever. Make it something you enjoy and that doesn't impact your busy schedule, but instead augments your personal life with fun and distraction and learning... Just my 2 cents on that :lol:

Back to commercial, how expensive would it be to dig out a long trench, let's say 4' x 100' x 1.5' deep and then put down a nice thick pond liner. Fill it with water, duckweed, and some mosquito fish (or whatever, you can even incorporate koi or something at low densities for supplemental/residual income streams). Some monitoring of water quality is required, sure, but not much. Harvest is quick and easy and requires no special training (like scooping poop, very easy). THEY DO THIS IN 3RD WORLD COUNTRIES WHERE ACCESS TO TECHNOLOGY AND AGRICULTURAL RESOURCES ARE LIMITED OR ABSENT. I don't see duckweed as creating anything short of a benefit, BUT what is the opportunity cost??? What else could you have built there, in place of that duckweed trench? What do you think? :ugeek:

[15mules]

UF What else could I have built in a 4' x 100' trench??? Another grow bed for edible plants? (No, I mean edible for people, not fish)
Ok lets go one step more with your concept, because I think we are going in the same direction with this line of thinking. how do we accurately compare the cost. lets say I take your idea of a trough full of Duckweed and i add a little more initial coast and build that same space (assuming that space is available to me) and we grow vegetables as an additional tough in our AP system. Would the additional income form those vegetables produce enough income, to buy more (store bought feed) than the feed produced in the same time period by the duckweed?? This would be a good test of the value of DW in my opinion.
Man, it is almost like we have ESPN or something we are thinking so much alike!!!!

[JCO]

Great discussion. I loved every minute of it and Duckweed International salutes you all. :lol:

However I think I can solve 15mules dilemma without much trouble here. 15mules, I know exactly where you live in Arkansas and that you are heading toward a commercial AP system for profit to be able to stay home and make money.

Forget duckweed :!:

To operate properly and efficiently like a well oiled machine without any hitches, a commercial AP system must be able to depend on each facet of the operation being as close to perfect as possible and constant as possible.

Forget duckweed :!:

You will not be able to grow duckweed in the winter without it taking up valuable space and resources inside your greenhouse. Resources which when used in other manners could produce more revenue than what duckweed could save you.

Forget duckweed :!:

Ever hear the song:-

"JIM DANDY TO THE RESCUE?" THAT'S ME..! 8-) :mrgreen:

[15mules]

JCO, now you went and threw another wrench in my plans!!, UF about had me convinced to forget about all of that lettuce and produce and stuff and go strait DuckWeed. That was going to be my biggest marketing Gimmick, Arkansas's only AP duckweed farm. Now you done gone and put doubt in my mind again!!! :?

Oh, Well so much for Duckponics!! :lol:

[JCO]

Sorry 15mules...you can't even us Duckponics...that phrase has already been coined by another of our members a number of years ago... TCLynx. She has ducks and a pool they do their thing in and she pumps it to the grow beds and swears by the technology. :shock: :o

Again, sorry...it's back to the drawing board...OH and before I forget...I have already ruled out the Chinese style greenhouse as a viable structure for your operation.... It's going to have to be the "AMERICANIZED CHINESE AQUAPONICS GREENHOUSE." :ugeek:

I know what you are thinking...don't ask...I am working on that solution for you and will not unveil it until it is done....! ;)

Not to fret...tis' I.... "JIM DANDY TO THE RESCUE" 8-)

and I am the "HERO" of this picture said "Snoopy" :lol: :mrgreen:

[15mules]

I look forward to hearing about your greenhouse ideas. I am guessing I will see some of the greenhouse stuff in the book?

I am also pretty sure I will be quite content to leave Duckponics to someone else.

[JCO]

You won't find anything about this new design I have for you as I just created it for your particular project...the suspense grows 8-) :mrgreen:

[15mules]

JCO, I got it, my new plan. Whaleponics!!!
Makes everything simpler, no more messing with a whole bunch of different fish with short life spans. Now all you have to have is ONE fish and it will live longer than we will, so no need to worry about breeding. Now I just need to figure out a grow bed ratio for my 10 ton fish? I also need to go back to Tractor Supply and see if they have a larger Rubbermaid container. :?


[attachment=0:2yg83mml]DSC03111.JPG[/attachment:2yg83mml]

[urbanfarmer]

JCO, now you went and threw another wrench in my plans!!, UF about had me convinced to forget about all of that lettuce and produce and stuff and go strait DuckWeed. That was going to be my biggest marketing Gimmick, Arkansas's only AP duckweed farm. Now you done gone and put doubt in my mind again!!! :?
This was not my intention! I am just trying to lead a mule to water, but I can't make you drink! :lol:

You are looking for an absolute answer. A "YES/NO" if you will. It's not so black and white, and the real answer is: IT DEPENDS.

That's why you must employ critical thinking while applying your base understanding of aquaponics to create a viable business model (and hopefully document it in a business plan).

Why not do a simple cost analysis to even determine if it's remotely feasible (like I mentioned earlier in the thread)?


You can assume the cost of the duckweed offsets the cost of your feed and calculate the cost/benefit ratio from that. Growing duckweed can be an inexpensive venture in itself.
So, let's say a pound of feed costs you $1. Let's also say the final cost of growing a pound of dry duckweed costs you $1 (mostly labor, let's just say). Although it may not seem like a good idea dollar for dollar, the end result is you get a larger fish yield. Why? Because the fish get better nutrition, obviously. Whether you want to do this is ultimately up to you. The greater the difference between the lowering cost of duckweed production or increasing cost of fish feed, the more likely you are to do it, but it's still up to you. Another idea is to not worry about producing duckweed. It really depends on your situation and preferences. Some people enjoy growing duckweed while others dislike it. Some people don't have a choice because they're employees doing the bidding of their employer! :twisted: Again, if it's right for your business really depends on you.

:mrgreen:

[15mules]

UF, I am not necessarily looking for a yes or no answer, as much as just having a discussion and some friendly debate. I really thought since I have read in other threads where there seems to be many feeding DW, to some extent, more people would chime in with their idea of how DW fits into their system.
I think DW as many of the topics brought up here can not be fully examined in the short time we have to make post. There have been entire books written on many of these subjects and we just have time to make a few comments here and there. Not as though as a chapter in a book, but entertaining and informative, just the same.

[urbanfarmer]

Yes, I understand! There is quite a bit of literature on duckweed. I have several duckweed (different species) experiments going right now. Nothing fancy, I am playing with many variables that affect their plant growth (things not touched on by available literature). For instance, recent studies have starting delving into the microbial ecology interacting with duckweed that affect the growth. Because this is such a niche area of science, they are areas lacking research with agricultural applications.

Back to the farm use, duckweed grows and can grow to the established rates of growth in the literature. People have been growing it for use in commercial applications for decades worldwide. It feels like we're beating a dead horse at this point...

How deep down the rabbit hole do you want to go? :lol:

[15mules]

UF, I am envious of the fact that you have time for these experiments. I have worked at home before and had lots of time to do lots of things, but no money to do anything. Now, I work away a lot and have the money to do something, but my time is very limited.
Next month when I get home, I intend to build my first system, I will have a short time to get it all together. I wish I had longer, but I simply do not. I can afford a few financial mishaps, but I cannot afford to waste much time! I can get the money back, but not the time. I do apologize, if I push for a direct answer, but the truth is, I am trying to gather as much credible information, as I can to base my initial decisions on.
I am sure you know, after being in AP for a while, there is lots of misinformation out there about all aspects of AP.
Thanks for your input.

[urbanfarmer]

I used to be like that too. The trick is to work smarter not harder! :mrgreen:

[JCO]

15mules, I know where you are headed and again I remind you:-


However I think I can solve 15mules dilemma without much trouble here. 15mules, I know exactly where you live in Arkansas and that you are heading toward a commercial AP system for profit to be able to stay home and make money.

Forget duckweed :!:

To operate properly and efficiently like a well oiled machine without any hitches, a commercial AP system must be able to depend on each facet of the operation being as close to perfect as possible and constant as possible.

Forget duckweed :!:

You will not be able to grow duckweed in the winter without it taking up valuable space and resources inside your greenhouse. Resources which when used in other manners could produce more revenue than what duckweed could save you.

Forget duckweed :!:

[Roger L.]

Hmmmm. Seems like I read a post like this one already by a new guy named Jim Dandy.

[15mules]

Yes, that Jim Dandy guy seems to really get around doesn't he??

[nadav]

I have read through this thread, and maybe this sounds dumb, but what is wrong with setting up a $3 plastic kid pond that I can buy at walmart and adding some water and duckweed, in a space of 3x3? Every 2 days, I scoop out some duckweed and supplement the diet of the fish. If I bought commercial feed, even $1 or $2 worth, I have to actually come up with $2. This way, I just scoop it up, plop it in, and come back in 2 days for some more. I don't mean it as a miracle food, but simply to lower my over all cost of feeding my growing fish. How does this not make sense to do?

[urbanfarmer]

I have read through this thread, and maybe this sounds dumb, but what is wrong with setting up a $3 plastic kid pond that I can buy at walmart and adding some water and duckweed, in a space of 3x3? Every 2 days, I scoop out some duckweed and supplement the diet of the fish. If I bought commercial feed, even $1 or $2 worth, I have to actually come up with $2. This way, I just scoop it up, plop it in, and come back in 2 days for some more. I don't mean it as a miracle food, but simply to lower my over all cost of feeding my growing fish. How does this not make sense to do?
This IS a correct way of thinking.

[bsfman]

I have read through this thread, and maybe this sounds dumb, but what is wrong with setting up a $3 plastic kid pond that I can buy at walmart and adding some water and duckweed, in a space of 3x3? Every 2 days, I scoop out some duckweed and supplement the diet of the fish. If I bought commercial feed, even $1 or $2 worth, I have to actually come up with $2. This way, I just scoop it up, plop it in, and come back in 2 days for some more. I don't mean it as a miracle food, but simply to lower my over all cost of feeding my growing fish. How does this not make sense to do?

Exactly what I do with duckweed. But I have about 50 square feet of surface area I grow it on.

[JCO]

I could not have said it better :mrgreen:

[Apollo]

How come no one is figuring the time, gas, labor into the cost of buying, hauling and storing the 50# bag of the commercial fish food?

How about future cost and availability of commercial fish food VS duckweed, after the SHTF?

[topz]

When shtf water maybe harder to find then the food to throw to the fish.

[Roger L.]

It will always rain topz. Collection is important but purification is key.

[Apollo]

My Rain Barrels will collect 1,280 gals with just over 1/2 inch of rain, 7 of my close neighbors have pools, plus I have an 8' X 12' spar. Keeping my 8' X 8' spar cover over the FT and keeping the water level 2" below the surface of the media in the GB's will slow my evaporation rate.

I'm looking for a good quality pump, about 1,200 - 2,000 gals per hr., head pressure around 9 - 10 ft. with as little draw on electricity as possible.

My main concern is power...I'm wanting to get a solar/battery set up, just to run the AP

[topz]

Your right about the rain. In the desert I would have thought more evaporation and less rainfall would cause more stress on the system.

I had forgotten about the rain catch you made Apollo.

[Agroregeneration]

I have read through this thread, and maybe this sounds dumb, but what is wrong with setting up a $3 plastic kid pond that I can buy at walmart and adding some water and duckweed, in a space of 3x3? Every 2 days, I scoop out some duckweed and supplement the diet of the fish. If I bought commercial feed, even $1 or $2 worth, I have to actually come up with $2. This way, I just scoop it up, plop it in, and come back in 2 days for some more. I don't mean it as a miracle food, but simply to lower my over all cost of feeding my growing fish. How does this not make sense to do?

Exactly what I do with duckweed. But I have about 50 square feet of surface area I grow it on.

You use the BSFL effluent correct? I sent you a message about that if you wouldn't mind checking your in box.

[Apollo]

Take the plastic kid pond, place it higher than your FT. Take some of your pump water an redirect it into the plastic kid pond using a series of splash down buckets. Then let the water return back to the FT though a non-firing bell siphon, using once again some type of splash down to help aerate your FT water.

No need to do water exchanges, once set up it's pretty much maintenance free. This plastic kid pond and also be used as a fry nursery, etc.

[JCO]

For more on duckweed, check out this thread http://www.diyaquaponics.com/forum/showthread.php?1837-NOW-YOU-VE-GOT-DUCKWEED-!.

I can't grow it fast enough to keep up with the demand. A small kiddie pool will grow enough weekly to supply 3 6" Tilapia...maybe. :mrgreen:

[Rio_Grande]

I was considering using it mainly because dad tends to over feed. It was my understanding it consumes Amonia and I figur if he over feeds it they will just eat it tomorrow and not contribute to the ongoing Amonia issues? Is that a laudable use for it?