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  1. #21
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    Re: NOW YOU'VE GOT DUCKWEED...!

    JCO, I'm curious about two things,

    1 - How do those siphons work? Can't really wrap my head around the fluid dynamics involved.
    2 - What is the purpose of the side braces on the GB? It seems to me that they are built in a cantilever setup and do not offer much structural integrity.

  2. #22
    Moderator JCO's Avatar
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    Re: NOW YOU'VE GOT DUCKWEED...!

    1 - How do those siphons work? Can't really wrap my head around the fluid dynamics involved.
    They work real well OH, you mean how to they WORK? If you will look at the photo of the, you will see that the long end goes in the F/T and then up and over the end of the F/T into the sump. The end in the sump is looped back up to the desired height to allow them to draw water from the F/T into the sump. When the water level gets below the upward end of the loop, they cease to siphon water into the sump. When the water level gets much lower, a sump electrical switch with a float shuts off the power to the pump.

    2 - What is the purpose of the side braces on the GB? It seems to me that they are built in a cantilever setup and do not offer much structural integrity.
    The 4" X 4" post there are more shallow in the ground so I braced them. The piece that you see running at an angle actually is braced against another piece (you can't see) running at a 90 degree angle under ground.
    JCO
    Irish eyes are always smiling but
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    so never forget
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  3. #23
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    Re: NOW YOU'VE GOT DUCKWEED...!

    So the valve at the top of the siphons is to fill them, removing air and start the siphoning process?

  4. #24
    Moderator JCO's Avatar
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    Re: NOW YOU'VE GOT DUCKWEED...!

    That was the general idea upon construction but it didn't work, so they are just hood armaments. Not everything works as planned.

    I submerged the PVC siphons and capped them off and put the over the side into the sump and uncapped them and the siphon began.
    JCO
    Irish eyes are always smiling but
    • "In the eyes of the world, you are only as good as your last success"
    so never forget
    • "MAN IS ONLY LIMITED BY HIS IMAGINATION"

  5. #25
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    Re: NOW YOU'VE GOT DUCKWEED...!

    Good stuff. I was impressed by those valves - some good bit of ingenuity there, too bad that it didn't work. Sometimes the simplest solution gets it done when the elaborate plan fails to perform.

  6. #26
    Moderator JCO's Avatar
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    Re: NOW YOU'VE GOT DUCKWEED...!

    It was something I thought would work but when I connected the water hose to them the water ran out both ends but would not fill the tubes so no siphon. AHhhhh, back to the drawing board and the tried and true method. This ole dog learned a new (old) trick
    JCO
    Irish eyes are always smiling but
    • "In the eyes of the world, you are only as good as your last success"
    so never forget
    • "MAN IS ONLY LIMITED BY HIS IMAGINATION"

  7. #27
    Members Roger L.'s Avatar
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    Re: NOW YOU'VE GOT DUCKWEED...!

    What about a one way check valve that only opened when the siphon opened. Would that help to end the siphon after the suction got to a certain vacuum?
    At what point did our government cease to be of the people, by the people, and for the people?

  8. #28
    Moderator JCO's Avatar
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    Re: NOW YOU'VE GOT DUCKWEED...!

    A non-spring loaded ball valve would have worked but I have never seen one for that size PVC.
    JCO
    Irish eyes are always smiling but
    • "In the eyes of the world, you are only as good as your last success"
    so never forget
    • "MAN IS ONLY LIMITED BY HIS IMAGINATION"

  9. #29
    Moderator davidstcldfl's Avatar
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    Re: NOW YOU'VE GOT DUCKWEED...!

    Quote Originally Posted by JCO
    Being as duckweed likes still water, how do you control the mosquito population?
    I don't know where the concept of duckweed needing still water to grow came from. The duckweed in my grow bed is flowing constantly in one end and out through the overflow stand pipe at the other back to the fish pond. It isn't swift like the Colorado rapids, but it's flowing at a pretty good rate.

    Additionally, I have 20 Ryukin goldfish in the grow bed to eat anything that moves that will fit in their mouths...no mosquito larvae there.

    Most of the info I've found on line says still or calm water. I guess that's left up to each person to figure out the meaning of 'still' or 'calm'.
    I had water draining into a tub where I was trying to raise duckweed. The duckweed got caught in an under tow...and ended up stacking up, forming a raft several inches thick.
    I don't have time to search for them, if anyone is interested I've posted a pdf or two about duckweed elsewhere in the forum. I think urbanfarmer has too.
    EDIT: I had a few extra minutes before the library's computer shut off.... ...here's a link to a file on duckweed...
    http://www.fao.org/Ag/AGAInfo/resources ... DW/Dw2.htm


    As far as your set up JCO, looks nice...lots of duckweed...
    Just wondering...does the glass tank have some kind of baffles...? I thought you mention one time that's where your solids settle (?)
    "Freedom is never more than one generation away from extinction. We didn't pass it to our children in the bloodstream. It must be fought for, protected, and handed on for them to do the same." - President Ronald Reagan

  10. #30
    Moderator JCO's Avatar
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    Re: NOW YOU'VE GOT DUCKWEED...!

    David, I took a look at the duckweed you provided....WAAaaaayyyy too much reading for me, however here are some photos. This one is of the water coming into my grow bed from the bio-filter. As you can see, I have other water plants in the grow bed also.



    Here are two photos of the Styrofoam ring that keeps the duckweed from escaping the grow bed. It doesn't have the water flow of a waterfall, but it is actually moving at a pretty good rate.





    Here are a couple of photos showing the water flowing back into the fish pond from the grow bed. That white blur you see below the surface is one of my 24 " breeder Koi.





    And in answer to your question about the sump tank, yes it does contain baffles that I installed. They are plastic afixed in place with silicone
    JCO
    Irish eyes are always smiling but
    • "In the eyes of the world, you are only as good as your last success"
    so never forget
    • "MAN IS ONLY LIMITED BY HIS IMAGINATION"

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