Backyard Aquaponics
A place to discuss aquaponics

just thourght perhaps i could try and extract a few ideas and the benefits associated with each. basically with the concept in mind to develop (first theoretically - hence this thread) and then practically. a system design that could be used in a variety of developing world contexts (depending on local material availability) to provide food, year round for household or community run systems.

so first things first, i thourght we could start by asking the question of how to most energy efficiently lift the water from the back end of the plant system back into the fish/water tank - assuming that gravity and head difference has been enough to allow it to passively flow out and through the 'hydroponic part of the system.

so just trying to stimulate ideas from your experinces, one idea that came from a chat with a mate down the pub (as the best ones often do) about using an archimedes screw, linked via a simle gear box to a small wind mill, therefore providing the wind was sufficient for lifting water at low lspeeds, and the top and bottom resevoirs were large enough to accomodate periods of no wind, it could at least provide an addition to solving the problem..?

what are your thourghts, there is of course airlift, direct pumping, manual lifting, or possibly the use of livestock to help?? (eg mice on a wheel?? )

anyway if you have any ideas, please get them down it would be great to know your collective thourghts.

cheers
charlie

Random thoughts to prime the pump...as it were

Windmills have traditionally been used here on more remote farms to lift water from the well. It is certainly a time-honored tradition.

Solar panels could be used to power a low-watt pump.

Wind and solar power together offset each other.

Train the fish to swim in a circle and push a little wheel!!

this is THE question. My experience with solar has been fairly positive, but the limitations are solar exposure and the expense of solar storage AND the slower pump circulation which does not aireate the rearing tank well enough for high demand stocking levels. I thought of supplementing the aireation duty with wind power but must wait until next year for the land and greenhouse for that experiment.

Bottom line, if the head fall is designed properly, i.e. adequate fall and grow bed distribution, It wouldn't require a high flow pump to move the water back to the top into a resevoir tank independent of rearing tank/s.
A bank of drop resevoirs lined with autosiphons that break off into the rearing tank every few seconds to achieve aireation would be non electromechanical and work, but how to create seperate resevoirs times at different intervals. It would be like building a clock i suppose.

From the rearing tanks, gravity would feed the rest of the system. The key is not getting the water to the top resevoir, it is providing constant rearing tank circulation.

Some thermal supplied aquafarms rely on natural flow through wells, but not applicable in moany regions of the world.

I hate editing obviously

Hi charlie if you are near a stream or creek a water wheel driving a small pump will give all the free energy you need

Windmill could be a winner, but would require much more water as you would need a 'bank' to allow for times of low wind/overnight

the archimedes screw, use nereby water flow to drive.

I think using the existing river to drive the pump (screw or otyherwise) is the go. There are a few sites that i have seen that have made such pumps, detailed instructions, and can uilise very slow flows by floating a V shaped collector across the river.

Obviously you're not wanting to pump river water, but the effluent, so you could hook up an alternator to your river device and generate sufficient power to run a pump up at the plant for your AP purposes. You'd loose efficiency in the alternator and the motor energy conversions, but hey, it free! 50% of free is still free

agreed a flowing stream or river would be ideal, and get rid of alot of the problems due to the energy harnessed in the flow, but and i am sorry to do this, need to try and develop a model system applicable for all type of scenarios particularily in the developing world where water can be scarse, ie in many parts of sub saharan africa or the middle east etc.

so yup really valid points about the benefit of having a flowing water source present, but we/i need to look at a 'worst case scenario' type situation. but totally agreed providing a source of energy/water was present a water wheel type arrangement or the device you mentioned steve, would be worth pursuing, but if there wasn't such a source......

michael_Ferrini - i like the sound of your idea about auto siphoning
"A bank of drop resevoirs lined with autosiphons that break off into the rearing tank every few seconds to achieve aireation would be non electromechanical and work, but how to create seperate resevoirs times at different intervals. It would be like building a clock i suppose."

--very nice idea can you expand on this a little or have any pics or diagrams? i will look further at the principles with a hydrolic engineer friend. just so that i am clear can i clarify (and correct me if i have got it wrong - you are saying that a system of autosiphoning tanks above the rearing tank can aerate the fish holding tanks, then the head from this is enough to flow through the system with a minimal head to lift back to the rearing/pre rearing tanks, ie with a pump (possibly a combination of solar and wind) sounds great, still slightly unsure of the autosiphoning bit that aerates the fish holding tanks. but like you ideas very much, can you tell me more...

thanks to all those that contributed, lets keep them coming...

charlie

does anyone have any info on auto0-siphoning?

cheers
charlie

Start Here, Charlie
http://www.backyardaquaponics.com/forum ... .php?t=685

Then look through more of the Hardware section. The place abounds with auto-siphon info.

yer great, sorry i found that shortly after making the post, sorry..

cheers
charlie

Hi all,Google spiral or coil pump and also rope pump basically the rope pump is an endless rope with equally spaced washers thatpass through a tube trapping water above them simple and very efficient. The coil pump is basically abig coil of polly on a large wheelthe open end of the pollydips into the water and then takes a gulp of air as it continues to turn then another gulp of water and so on , again very efficient very very simple to build ,Both are very third world appropriate technologies .

hehehe - had to go and check 1st but the spiral pump link was put up this morning on Monya's thread

Probably doesn't count seeing its on Mo...........

LOL great minds and all that !