Quote Originally Posted by 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.
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.

Quote Originally Posted by 15mules
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!

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.