Backyard Aquaponics
A place to discuss aquaponics

this is the perfect example for transporting the bike back to your AP site....

Hi,

A newbie here from India and was going through this interesting thread.
Looking at your requirement and assuming you are fine with battery operated appliance; in your budget of course $50 to $100. Probably it makes sense to buy a battery operated (rechargeable) air pump of considerable capacity to do the following.

1. Aeration - primary purpose of course
2. Circulation - by using the air pump to lift water (maybe will need system design change to keep the head as low as possible)

For example - http://www.amazon.com/Deep-Blue-Professional-ADB61037-Hurricane/dp/B00BUFXOH0/ref=sr_1_2?s=pet-supplies&ie=UTF8&qid=1449142584&sr=1-2&keywords=Battery-Operated+Air+Pump

http://www.deepblueprofessional.com/air-pumps.html
INPUT PWR: 110V 120V @ 60HZ. PWR USAGE: 12W @ 36 INCHES. OUTPUT: 65 GPH. PORT SIZE: 2 - 3/16. BATTERY: 6V NI-CAD OR (4) D-CELL. PROTECTION: OVERLOAD & DEEP. CYCLE DISCHARGING.

Maybe, the flow rates will be lesser than optimal rate but I think it will take your system through during the long power cuts.

Cheers
Pankaj

There are 75 watt inverters for about $10 - $20... or you could look into a UPS (uninterruptable power supply) that would have the battery, inverter, and the hardware for charging the battery and automatically switching from line power to battery power and back as needed; already built in.

If you can find a small UPS that allows additional external batteries to be added; I think it would work out better than buying a large (high wattage) UPS just to get the higher battery capacity. http://www.instructables.com/id/Make-your-computer-UPS-last-for-hours-instead-of-m/

It would be interesting to read the grant application, or at least know what the stated goal was.

most likely based upon this document (released 2014) - you will see there are lots of similarities to the OP....
pretty typical case of UN-FAO says its good, funds requested to "do one of these in xxxx country "

FAO 2014 Small scale food production AP report - http://www.fao.org/3/a-i4021e/i4021e00.pdf

Classic case where the outcome and recommendations are technically correct but does not necessarily consider the economics, realities or risk of third world implementation. Doc comes out of FAO Rome Italy.

eg. OP has hit a snag with the 'sealer' for the concrete - which is often excluded in SE-Asia and 3rd world situations (page 69) but readily available and required to be used for food grade installations in most developed countries..

Small-scale aquaponic food production Integrated fish and plant farming FAO PAPER page 69:
Sealer is required to avoid toxics from concrete to enter the system. Is this really a risk? Otherwise I like to go for a concrete tank to save on the budget.

aged concrete is ok, but yes new concrete is bad, not only because it leeches lime which raises the PH, but it also leeches carcenogenic chemicals if i remember right.


i think brick with minimal concrete / mortar is not quite as bad, maybe.

Yeah we're moving away from my first idea of a manual aerator (wind up or something). But it might work (providing we can import taxfree through luggage of visitors)

1. Deep blue professional 5 (120dollar or so), + importing to Ethiopia will be a lot (tax might be even a 100%)

2. Normal D-battery aerator, not sure if provides enough volume (+/- 15dollar) + D cell battery charger (30dollar) = 45 dollar?


_______________________________

About the project:
We're starting at 3 different sites and for other two sites materials are already bought (so set up is flexible but we cannot move away from NFT/growbed/fishtank set-up. The research wants to needs to have same sort of systems at all sites. The good thing is that there will be one (experienced) Aquaponics person available 1 day a week for a full 2 years. Next to this we seek to have a continuous aquaponics intern from the university in Holland (Wageningen) present at the project. This to really assist all eight systems, we don't leave the farmers to operate everything themselves entirely.

There isn't normally anything dangerous in concrete... the standard rule for water used in concrete was always "use only water that you would drink" plus sand, stone, and cement. Most of the concrete additives are just soaps or dyes; there should not be anything carcinogenic... no special protection is needed when handling or working with fresh concrete except to avoid alkali burns on your skin or eyes really.

The only real "problem" I see is that portland cement concrete is not very acid resistant; so if your pH is below 6.5 you might get more rapid deterioration.

Or if someone is illegally disposing of toxic waste or radioactive materials (it has happened here in the US) in the concrete.

not a google scholar article, but its pretty much saying what i remember in the past, its water contact that matters, not just "concrete is toxic to all"

https://beauregardparishcountrylife.wor ... -concrete/

I think the author is over-stating the danger; but everybody has to decide for themselves I guess.


http://www2.epa.gov/coalash/coal-ash-reuse


http://precast.org/2013/11/the-future-of-fly-ash-use-concrete/

I'm certainly no expert, but I've either handled, hauled, or been personally responsible for the testing, quality & content of a lot of uncured concrete & concrete products... and I don't have cancer (yet).

but thats like saying that you havent got zinc poisoning even though you may have drunk water from a galv. tank.... its about what the fish can handle....

Yes, that wasn't really the point of my post, it was just a joke... the point is that as far as the EPA is concerned; fly ash in concrete is no worse than the portland cement it replaces.

I don't intend to start an argument, there is more info on concrete drinking water tanks/systems: http://www.concretethinker.com/detail/Leachability-and-Concrete.aspx

Yes, that wasn't really the point of my post, it was just a joke... the point is that as far as the EPA is concerned; fly ash in concrete is no worse than the portland cement it replaces.

I don't intend to start an argument, there is more info on concrete drinking water tanks/systems: http://www.concretethinker.com/detail/Leachability-and-Concrete.aspx