Automatic Duckweed Feeder

[Sylvia Bernstein]

OK, I love this idea but I wanted to see what the rest of you thought  

Click here to read this guy's post about his design for an automated Duckweed Feeder.  Does anyone know this guy?  I'd like to get him in here to talk with us!

[TCLynx]

120 things in 20 years. That is really familiar... Hang on let me go look at his post.

[TCLynx]

Ok, I've seen the fish feeder that is in his blog. That 120 things in 20 years is familiar from the BYAP forum. I've subscribed to the thread about teaching your fish to feed themselves. I'll go see who's thread that is.

Don't know him personally but I do know him on BYAP
Profile on BYAP
BullwinkleII
:)

[Sylvia Bernstein]

You want to invite him to join here? I love the inventor spirit!

[TCLynx]

I left him a message, perhaps he will stop by.


Sylvia Bernstein said:

You want to invite him to join here? I love the inventor spirit!

[BullwinkleII]

Hi people.

[TCLynx]

Hay there. Looks like you did stop by. Maybe you could put that side view image on here too?

[BullwinkleII]

Here tis...


The duckweed bed is divided by the incoming stream of water. The overflow through the standpipe in the PVC gutter takes a "dose" of duckweed to the fishies bellies.

the full story is here ...

http://120thingsin20years.blogspot.com/

but I actually think that side view almost speaks for itself :) Thanks for the feedback TCLinx. I have no idea why I thought the top down view would be better. Perhaps my animation skills where not quite up to the task yesterday.

[Sylvia Bernstein]

I love this! Thanks for the awesome animations. Is your vision of this (I'm assuming you don't have it set up yet because of the use of animations vs. photos) have the flow from the sump coming in as part of the fish system, or is it on a separate pump? Do you worry about too much water agitation for the duckweed?

[BullwinkleII]

Sylvia Bernstein said:

I love this! Thanks for the awesome animations. Is your vision of this (I'm assuming you don't have it set up yet because of the use of animations vs. photos) have the flow from the sump coming in as part of the fish system, or is it on a separate pump? Do you worry about too much water agitation for the duckweed?

I worry now! :)

Is agitation an issue ?

I was planning to incorporate this design into the new system that I'm building. I only just managed to get a handful of duckweed a week and a half ago, so I don't really know anything about it, other than how it moves and spreads out when I pour in water.

I put some in a large container and it started to develop an oil slick (added fish emulsion). I figured it was because of a lack of oxygen so I added an air stone. It seems to be loving it. It's amazing how quickly it grows, although that might be an illusion because its only growing in 2 dimensions. I suspect a lettuce would look even more spectacular if you spread all those leaves out.

Any agitation should be mostly of the current or next "dose" of duckweed so it shouldn't matter if it doesn't like it as it will be fish feed within hours. The stuff further away from the incoming stream of water shouldn't make to much of a stir. I'll have my duckweed rearing tank separate from the feeder, and scoop some in to the feeder every week or so. I'd rather have duckweed growing in some goat dung tea or something rather than having it use all my nutrient from the aquaponics system that would be better spent on veggies.

Then again... this stuff is always fluid :) sometimes I just have these ideas and never build them. They just bang around in my head unless I get them out :)

I do intend to build it though (or at least something that does the same thing), so I'll post the results up here when I do.

The plan would be to divert a small amount of water from the flow from the sump to the fishtank. It shouldn't really matter how much it needs because it will be flowing directly into the fishtank anyway. If needs be, I could put all the flow into the feeder, but playing around in a bucket with duckweed indicates it will only need enough flow to get the weed over the lip of the standpipe. The standpipe can be quite narrow as the duckweed I have is small. So I think the flow will only need to be the kind of flow you would get from say 5 or 10% of a garden hose. This is all guesswork though.

It probably would have been quicker to cut a small length of PVC and just make it, not with a pump and all, but just pour a glass of water in or something. The animations are partly because I'm learning how to animate stuff. I suspect having some animation skills will be a very useful thing to have during this next nineteen and a half years :) Animation skills might prove to be one more undocumented advantage of doing 120 things in 20 years. Two others being, learning how to type, and learning how to express myself a little better using this writing caper. As a participant in ongoing lifelong education, I could previously perhaps best be described as "lapsed". But I have the 20 years after the next 20 to catch up. Then I can start applying it. :)

[Sylvia Bernstein]

LOL. I never thought about animation skills being potentially important until now. I see your perspective.

I'm a duckweed flunky, so I shouldn't be handing out any advice here (there is a post here about my tribulations last summer, with lots of great advice in the thread). I did learn, however, that it likes oxygenation and a little movement, but hates a lot of agitation. Can be easily adjusted by lengthening the inflow pipe.

Looking forward to seeing the photos someday.

[BullwinkleII]

BTW if anyone cares, the animation program is open source and free* like all good things in the world, and can be nabbed here

*free as in freedom, and free as in free beer.