[757labs] Beau's aquaponics project

[Lee]

I know someone who has a small outdoor pond shell (about the size of a
2-seater couch according to her) that she's not using. Not sure if it would
be of any use, but she wanted to to throw it out there if it could be of
any use.  It's just the pond shell, no pump.

--- Lee


On Tue, Mar 13, 2012 at 9:46 PM, Beau Turner <beau.turner at gmail.com> wrote:

> Excellent info, currently using a larger pond pump (for the tub) of
> 130-170 gal per hour. This has about a 4'-0" top height of pressure and
> with the 1/4" line split at the top that then goes to two flow control
> valves allowing flow control to each column.
>
> Working ok for smaller setup, suspect will need a pool type pump when
> going much larger.
>
> Reading through the other links, great info. Keep it up.
>
> -bt
>
>
>
> On Mar 13, 2012, at 8:39 PM, Matthew Kelly <seawolf013 at gmail.com> wrote:
>
> Howdy Beau and contributing folks,
>
> This is Relentless,
>
> I have been doing a few calculations on this project since I talked to
> Beau the other night.  I've been looking at what kind of pump would be best
> suited to the needs of small scale deployment of this project.  Currently I
> believe the pump that is being used in the window prototype is a small fish
> tank water pump.  These are readily available at almost any pet store,
> however, these pumps are not traditionally designed to have a high head
> (operating pressure), which means the vertical build height is limited.
>  They usually  only have a few inches of head, meaning they will only pump
> a few inches upward.  I believe Beau was having trouble getting the pump to
> cope with the several feet of height present in the first gen of the
> prototype in the window.  A smaller diameter tube was tried out to my
> recollection, if I had to guess based on a simple fluid calculation (
> http://www.efunda.com/formulae/fluids/manometer.cfm ), I would imagine
> that this likely did not satisfactorily correct the problem as the head
> loss in this flow path is due to gravity not friction from the tube.  Long
> story short you need a stronger pump if your going to build high or build
> with long runs of pipe, tube, accessories, or fittings.  Of coarse a
> stronger fish tank pump could be purchased for the right price, however in
> my research I have found that the head value for fish tank pumps seams to
> be something of mystery to most of the outlets selling them, so I can not
> opine on a better model.
>
> In the long run this may or may not be a problem as I understand that the
> goal is to achieve a modular design.  Perhaps one small pump could be
> placed into each stackible unit with a inlet and outlet that links them all
> together.
>
> However, given that you are looking for a fairly low flow rate and low
> cost.  I recommend looking into a peristalic pump design (
> http://en.wikipedia.org/wiki/Peristaltic_pump).  Its a positive
> displacement pump, so it has low flow rate and relatively high head.  This
> design could be produced quite cheaply using 3D printing and some common
> hardware to produce the rollers necessary to crimp the tubing.  And if you
> still plan on building the planters in a PVC pipe the ID of the pipe could
> partitioned and serve as the ID of the pump on the end of one of the
> planter tubes.  If you let me know some more solid details I could perhaps
> make a small prototype pump for you.
>
> I figure the design could be easily made with a few 3D printed parts that
> used skate bearings to turn, and equip it with a small DC drive motor and
> drive train that could easily be powered with an H-Bridge via your
> microcontroller.
>
> However if you want to go really large scale this sort of pump becomes
> limiting because of its limited flow rate and it would be necessary to
> evaluate a piping system, head loss, and pump selection based on what ever
> other physical needs you have.
>
> Also on a side note, I wonder if you have considered the addition of a UV
> Sterilizer to the flow path.  This would cut down on some of the nasty bugs
> that will likely be present with the fish such as salmonella and will have
> the added benefit of cutting down on algae build up which should also lower
> the periodicity between cleanings of the fish tank.
>
> Well let me know what you think.
>
> _______________________________________________
>
> 757labs mailing list
> 757labs at 757labs.org
> http://757labs.org/cgi-bin/mailman/listinfo/757labs
> If we knew what we were doing it wouldn't be research.
>
>
> _______________________________________________
> 757labs mailing list
> 757labs at 757labs.org
> http://757labs.org/cgi-bin/mailman/listinfo/757labs
> If we knew what we were doing it wouldn't be research.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://757labs.org/pipermail/757labs/attachments/20120313/2d9eacc7/attachment-0001.html>