Backyard Aquaponics
A place to discuss aquaponics

Hello people,

Currently I'm setting up eight small scale Aquaponics systems in Ethiopia. For this were using 2 IBC tanks as fishtanks. The biggest challenge are powercuts, normally around 4 hours, something which the fish can handle. But once/twice a month there is a powercut of 8-20hours.

How can you aerate the fishtanks without electricity/solar/wind, I was thinking of some wind-up mechanism with a heavy weight (like the old livingroom clocks), it would be fine if you'll have to wind them up every hour...

There is maybe 50$ in the project budget available for this, therefore carbatteries/inverters/solarpanels are not an option and there is almost no wind since we're building in quite thight backyards....

Any ideas?

I have no idea how effective it'll be, but larger ponds can use big wheels that scoop up the water and keep it splashing around, it adds oxygen to the water. Depends on how handy you are with knocking stuff together.

Maybe you could pump water up to a higher height when the electric is working and let it drip down for oxygenation when the power goes off

Maybe you could drop water onto one side of a water wheel and cause agitation with this as well as the water drops. Stair steps might also work. Either way the limitation is how long the water can be released before it runs out.

Is compressed air and option?

Find one of those old hand pumps

and set it up as a seesaw that kids can play on, get them to play on it for ages.

make that, using pvc pipe, washers, some string, 2 pulleys and a handle to turn it all.

..
I have seen a setup, where a compressor had a blade fitted and used like a wind generator to produce air pressure..
I wonder how you would go with a car air-conditioning compressor..

I know there will be an issue with oil, but innovation may get it working..
..

no power, $50 budget man.

These little fireplace bellows are only $10usd... possibly if you had one of these with a check valve pumping into something like a 30 gallon plastic barrel (or PVC pipe capped on both ends)l and then some air stones attached to that?

Perhaps a person could pump up a small pressure in the barrel and then rest or pass the bellows to another person... the drum/barrel would be the air "reservoir" that evens out the pressure spikes?



(Not to scale)

Bellows: http://www.fleetfarm.com/detail/Panacea-Fireplace-Bellows/0000000036216?utm_source=googleps&utm_medium=shopping%2Bsearch&utm_campaign=google%2Bproduct%20search&gslfah&gclid=CKmSqaD0sMkCFQmOaQodydMBNQ

I don't know what else you can do with the budget & no power.

That looks like a winner... with an old bicycle.

Indeed.. but I would wonder if there are car wrecks with air conditioners..

Whatever ... for $50, there has to be a deal of innovation..

OK.. so I deleted all that rubbish about WIND, having re-read the challenge..

1.. no wind, and no power during disruption
2.. we have a typical IBC. AP. setup and not ponds where we.can splash lots of water around

My mind goes back to the Car-AirCond compressor, driven by a bike..
And some form of pressure accumulator, so that you might leave the bike for a time.

Can't think of anything else that can be adapted for a small sheltered backyard situation...

Bottom line, you need mechanical power first, and perpetual motion is still a myth..

What about a blue barrel, sunk into the ground and plumbed into the system .. it will fill with water which will give a pressure head to power the air accumulator that it becomes..
So you peddle away and this pumps air into the barrel and pushes water back to the system..
The air from the bike-compressor, bubbles into the BOTTOM. of the barrel, aerating that water as it enters..
The building air pressure will push the aerated water back to the FT.(a minor benefit, but a benefit).. and all the time the accumulated/pressurised air will bubble into the FT but from a limited depth..

I can't see any other way of supplying the mechanical power, air storage and delivery in a confined area..

The bike/compressor could be conveniently located and should have a filter device to ensure oils don't make it to the FT..
..

i think it has to stay very low tech.

the bellows are a good idea too, certainly have to think of a way to use them that requires minimal effort too.

An overhead IBC running through the fish tanks to another storage IBC with a human powered pump system to return water to overhead tank every hour or as required would be my choice but probably way over budget.

https://en.wikipedia.org/wiki/Human_power

I think you would really have to work on getting very high oxygen transfer efficiency because you have such a small amount of sustained power available; if one poor bugger has to keep the fish & bacteria alive for hours & hour.

If you cold make the string pump quite tall and perhaps have the water flow back down over the outside of the tube in basically a thin sheet (high surface area) or rain down into the tank for surface aeration?

the bacteria arent as critical as the fish, i have turned my system off for a week at a time with no detriment to the bacteria in the growbed.
the fish still need aeration though.

just need to solve the minor perpetual motion problem and we will be away.........

having said that the more likely option is via fire - either thermal or via steam.

44 gallon drum or something..... might be able to drive either a small fan/impeller and agitator or a dynamo (MYO) + aerator.

or else go the whole hog and invent a small steam engine

[edit] pity its not a first world $50 problem - allowing for US$ that gives us A$70 and more than enough for a small 2nd hand 2-stroke engine or device with same attached, via gumtree or similar.......