Low Energy Aquaponics - LEAP

I started a thread over at BYAP (Backyard Aquaponics) to get some input on how we could develop a low energy aquaponics system that could be powered by solar. Here's the link: http://www.backyardaquaponics.com/forum/viewtopic.php?f=1&t=11704&sid=3805f2540cc5d4e5bdd52bc327ef5df3

The idea is a system with a max requirement of 10 watts. The solar component for a 10 watt system can be had for under $400 USD. Of course, if we can get the power down even further, that's fine, too.

To meet this goal, the going idea is a constant flood, constant height (zero/low head) recirculating system. We're looking to turn over the FT (fish tank) volume every hour at least, and stock at appropriate rates (maybe up to 25kg/m3).

The response has been awesome, and currently, the talk is about using airlifts or powerheads for circulation. Folks are running tests, and a member has achieved 1200 lph with 5 watts on an airlift, making that do a 1,000L FT (IBC) just fine.

Just to be clear, that's a $300 USD solar system for a 1,000L FT and 1,000 GB (grow bed) in a constant height, constant flood configuration running 5 watts.

So, I want to get as many ideas as possible, so what are the thoughts over here? How would YOU do a 10 watt system, and how can we stretch the limits of the box to make this work?

If this sounds foreign to you, follow that links and start learning about aquaponics. This is kinda advanced AP discussion, but I think most folks can get the concepts with a bit of reading. It seems like to reduce energy in recirculating aquaponics systems, you have to reduce the head to almost zero. By doing that, you require the minimum amount of power to pump the maximum amount of water (not necessarily the most efficient way, just the most practical). So, we're looking for ways to reduce that head, and reduce the pump sizes. So far, 10 watts seems easy to meet, 5 watts is possible, and I think we could even trim it to 3 watts, if we really try.

The main consideration, in aquaponics, I think is; is the water moving sufficiently to provide oxygenation for the fish? The plants don't need much water movement, just enough to move nutrients around sufficiently. For aquatic plants, this is virtually nothing. But fish require oxygenation. Does the low energy system provide oxygenation for the fish, is the only serious consideration for me personally. But I'm not mechanically inclined, so I don't know if I can figure this out on my own......

actually, the plants need oxygen, too, especially at the roots.

Yes, we are turning over the volume of the fish tank every hour, so things get stirred up and aerated just fine. This is the standard turnover rate with aquaponics and constant flood systems.

Tyler, what sort of energy requirements does your AP system have?

Beats the heck out of me! I'm a complete beginner.

though i have not yet set up a system and may not for a long time to come, i am very interested in aquaponics and love to hear about the cheapest methods because i find that if it is possible to run one without power or with very minimal power, one can produce a vast amount of food in a small area as well as an exotic method in most places
i eventually plan to have an aquaponics system set up in a walipini greenhouse so that i can have exotic fish and exotic out of zone plants to completely irradicate any inorganic competition in the area
my only idea atm for an aquaponics system without power would be to use a widow water pump and use the energy of one of your exterior ponds/streams to pump the water into the grow beds, this is all kind of tenatively planned and will likely be revised a good thousand times before i begin construction and another million while constructing lol
fortunately there are pumps and such that use no energy at all, the whole idea is to figure out how you can use these things to run the aquaponics system and keep the water at damn near maximum oxygenation level, as is nessacary for healthy fish and especially roots if they are to be constantly submerged

im on my way to llok at your thread in the other forum now:)

right now, we are achieving great results (5 watts to pump 320 gallons per hour) with using air to pump water. You also get a lot of aeration in that configuration.

Abe Connally wrote:right now, we are achieving great results (5 watts to pump 320 gallons per hour) with using air to pump water. You also get a lot of aeration in that configuration.

Wow! 5 watts to pump 320gph that's pretty damn impressive. Now I'm thinking I might need to list a few more considerations on my redesigned AP 2.0 system for this summer. The lack of head could be a problem with what I have setup, but still good to think about.

What about using a hydralic ram to move the water?

Or possibly a thermal siphon?

Just some brainstorming ideas...

I just read the first page of your discussion on the other site, so I hope I am not repeating someone's idea.

Seems that your only power need is for the air pump, and your goal is to create a 2 psi air stream. Like with a solar electric system, the best route is to store the electricity in a battery, and then use the stored power, in case the sun isn't shining, etc. So, why not focus your effort on storing air pressure? Hook up a windmill (or water wheel if you have a moving stream near!) to an air compressor, and store the air in a giant tank. Maybe one of those large propane tanks or something. You'd need a pressure relief valve to keep it from exploding, and a regulator to have it release 2 psi constantly. Lots of calculations to work out - how much psi can a 250 or 500 gallon tank safely hold, and how long will that volume of compressed air be able to sustain a 2psi output at the volume you need for when the wind isn't blowing, etc. For that matter, can your electric air pump be used to pressurize the tank within your power requirements?

Mark Edward wrote: Hook up a windmill

What size windmill is needed to compress air?

yes, that is being discussed on the other thread. Some people have mentioned that with higher pressures come higher inefficiencies, and there could also be temperature issues.

I think it is a possibility, as an alternative means of storing the energy.

Propane tanks can easily store at 150psi or more, but you have to be careful with what sort of tanks and compressors you use to avoid putting compressor oils into your fish tank.

But, say you could store 1L of air at 150 psi, but you release it at 2psi. All of a sudden, you have 75 L of air at 2 psi. Pretty neat, huh? The only thing is that as the pressure drops, the flow will, too, because there is not as steep of a pressure gradient, so you will start getting diminishing returns. But, say you stay above 10 psi in the tank, and you can store 500 gallons at 150 psi, that's 7500 gallons of 10psi air stored.

I imagine that storing compressed air is a lot less efficient than lead acid batteries, but it is also easier to build at home, and could have a variety of inputs, from wind, hydro, solar, human, animal, heat, etc.

Just wanna pop in here with a plug for aquaponics! Glad to see these posts, Abe, and I will check out the Backyard Aquaponics site! I'm still in the researching stage and just found a very active aquaponics group in Tucson AZ:
Tucson Aquaponics Project
http://www.tucsonap.org/

Went to their monthly meeting on Tuesday and was blown away by the expertise and helpfulness of the group's founder, plus the guests he has lined up to come speak. Aquaponics combines raising (usually) tilapia fish with raising veggies /fruits in closed-loop systems that require very little input of energy or resources. It can reduce typical water usage by 90% with all the benefits of fish waste, fish fillets etc.

The Tucson group is having its first home tour of existing set-ups tomorrow.
http://www.meetup.com/Tucson-AquaPonics-Project/

A couple in Hawaii designed a modified system of their own that is easy to replicate. They provide training and plans.
http://www.friendlyaquaponics.com/

What caught my attention was this exciting little factoid on their website:

An additional benefit of farming aquaponically (that we noticed after our first system was operational for six months) was that the mosquitoes on our seven-acre farm had COMPLETELY disappeared! We live in Hawaii, where there are as many mosquitoes as any other tropical area... even during a drought, when the soil was dusty and dry and there was no standing water visible anywhere, there were still clouds of mosquitoes at dawn and dusk...

When we built our first aquaponics system we introduced a few mosquito fish (gambusia affinis), and neon tetras into our system water. They spread throughout the systems... and soon had become a self-sustaining population numbering in the tens of thousands. Six months later we noticed there were simply no mosquitoes around any longer... we’re not certain when the number went to zero, but it was sometime during that six-month period. That was three years ago.

How does this work? We live in the center of a deadly efficient mosquito trap: every female mosquito in the neighborhood can sense the roughly 50,000 gallons of water in our aquaponics systems, and comes to them to lay her eggs. Each egg hatches into a larva, which is then promptly consumed by one of the hundreds of thousands of mosquito fish in our water BEFORE it can ever develop sufficiently to hatch into an adult mosquito...

We don’t know what the effective radius of our mosquito eradicator is, but we’ve gone to the corners of our seven-acre property and haven’t found any mosquitoes there; we think there’s a good chance it is significantly reducing mosquito populations on the farms around us. We need help and funding to continue research into this phenomenon in order to understand it better, and to develop it to the point where it can easily be implemented in any location or culture. This could make a huge difference in the lives of people worldwide who currently lose family members to malaria and other mosquito-borne diseases.

Brad Davies wrote: The lack of head could be a problem

Seriously no one is going to touch that? Ok I guess it's up to me...

"Isn't it always! hahaha"

Mark Edward wrote: Hook up a windmill

Hmmm.... that gets the wheels turning, pun intended.

What if the windmill is used to pump water up from the system into a holding tank, no pressure no compressed air, just a water holding tank. The water could then be moved back down via gravity. Flow could be regulated with a valve set to whatever GPH you needed / could maintain with the windmill. Having a large water holding tank would be like a large battery storing potential energy through the times of no, or minimal wind. Attached a feeble ms paint drawing.

Brad, is the water in the windmill tank part of the overall system? (sorry, couldn't see the picture) That is, is the water in the windmill tank part of the total volume of water in the aquaponics system? If it is, one would need a large enough sump tank to store the water during times when the wind doesn't blow enough to pump it to the upper tank, it seems to me. In a constant water height system, one always needs a large sump tank to store excess water when the pump (whether electric or wind) is not running.

Tyler Ludens wrote:Brad, is the water in the windmill tank part of the overall system? (sorry, couldn't see the picture) That is, is the water in the windmill tank part of the total volume of water in the aquaponics system? If it is, one would need a large enough sump tank to store the water during times when the wind doesn't blow enough to pump it to the upper tank, it seems to me. In a constant water height system, one always needs a large sump tank to store excess water when the pump (whether electric or wind) is not running.

Changed the image file to a JPEG, hopefully that helps. Yes the water that's in the system would be the same water that's being pumped. I agree that you would need enough capacity to hold the water incase of a windmill failure, and / or have over flows installed on your sump incase it does get to much water in it, good practice anyway if rain can enter your system. I don't see why you couldn't also have a sump pump hooked to a float switch in the up tank that would pump water from the sump to the upper tank in case the wind wasn't blowing; redundancy is always a good idea in aquaculture.


Hypothetical scenario:
So let’s say you need to move 100LPH for your system. You install a 1,000 Liter upper tank that is topped up with a windmill pump. Once the upper tank is full you could run your 100 LPH for 10hours with no wind, or electricity. If there's no wind the backup pump could kick on, top up the upper tank you have another 10hr of flow.

Considerations:

If in the above example your windmill pumps less than 100LPH it would never be able to fill up the upper tank.

Your sump should be able to hold the extra capacity of the upper tank, or have something planned to divert the extra away just in case.

The more water you could move with your windmill, the less electricity you would need.

I would draw the water off from the sump or after it went through a solid separator to try to help keep the pump holding tank clean.

Disclaimer:

This is all theory, I have not tried this, and am not claiming it will 100% work. I think it might be a solid idea though.

Thanks for clarifying, Brad.

Brad Davies wrote:

Brad Davies wrote: The lack of head could be a problem

Seriously no one is going to touch that? Ok I guess it's up to me...

"Isn't it always! hahaha"

Mark Edward wrote: Hook up a windmill

Hmmm.... that gets the wheels turning, pun intended.

What if the windmill is used to pump water up from the system into a holding tank, no pressure no compressed air, just a water holding tank. The water could then be moved back down via gravity. Flow could be regulated with a valve set to whatever GPH you needed / could maintain with the windmill. Having a large water holding tank would be like a large battery storing potential energy through the times of no, or minimal wind. Attached a feeble ms paint drawing.

rather than messing with pressurized tanks that can reduce air temps and all that jazz, just use the wind when it blows to pump water up to a small tank (maybe a secondary sump) and have it flow from that tank at a regulated rate, i like it

so you basically have a fish tank in a mid level setting, a sump tank lower than the FT to hold overflow from that and give the windmill something to pump FROM and the water gets pumped from that to a tank stored above the FT, where it is then released into an ebb and flow or constant height GB
the filtered water then flows to the FT and cause overflow to go to the bottom sump tank, starting the process over again:)

Joy Banks wrote:Just wanna pop in here with a plug for aquaponics! Glad to see these posts, Abe, and I will check out the Backyard Aquaponics site! I'm still in the researching stage and just found a very active aquaponics group in Tucson AZ:
Tucson Aquaponics Project
http://www.tucsonap.org/

Went to their monthly meeting on Tuesday and was blown away by the expertise and helpfulness of the group's founder, plus the guests he has lined up to come speak. Aquaponics combines raising (usually) tilapia fish with raising veggies /fruits in closed-loop systems that require very little input of energy or resources. It can reduce typical water usage by 90% with all the benefits of fish waste, fish fillets etc.

The Tucson group is having its first home tour of existing set-ups tomorrow.
http://www.meetup.com/Tucson-AquaPonics-Project/

A couple in Hawaii designed a modified system of their own that is easy to replicate. They provide training and plans.
http://www.friendlyaquaponics.com/

What caught my attention was this exciting little factoid on their website:

An additional benefit of farming aquaponically (that we noticed after our first system was operational for six months) was that the mosquitoes on our seven-acre farm had COMPLETELY disappeared! We live in Hawaii, where there are as many mosquitoes as any other tropical area... even during a drought, when the soil was dusty and dry and there was no standing water visible anywhere, there were still clouds of mosquitoes at dawn and dusk...

When we built our first aquaponics system we introduced a few mosquito fish (gambusia affinis), and neon tetras into our system water. They spread throughout the systems... and soon had become a self-sustaining population numbering in the tens of thousands. Six months later we noticed there were simply no mosquitoes around any longer... we’re not certain when the number went to zero, but it was sometime during that six-month period. That was three years ago.

How does this work? We live in the center of a deadly efficient mosquito trap: every female mosquito in the neighborhood can sense the roughly 50,000 gallons of water in our aquaponics systems, and comes to them to lay her eggs. Each egg hatches into a larva, which is then promptly consumed by one of the hundreds of thousands of mosquito fish in our water BEFORE it can ever develop sufficiently to hatch into an adult mosquito...

We don’t know what the effective radius of our mosquito eradicator is, but we’ve gone to the corners of our seven-acre property and haven’t found any mosquitoes there; we think there’s a good chance it is significantly reducing mosquito populations on the farms around us. We need help and funding to continue research into this phenomenon in order to understand it better, and to develop it to the point where it can easily be implemented in any location or culture. This could make a huge difference in the lives of people worldwide who currently lose family members to malaria and other mosquito-borne diseases.

excellent observation
there is not an excess of mosquitos but a dearth of mosquito eaters
nature is fecund and wants as many different flows of energy and material as possible
the designer's mission to identify them and put them to productive use
rather than quelch them with poison

Tyler Ludens wrote:Thanks for clarifying, Brad.

Not a problem

Devon Olsen wrote: rather than messing with pressurized tanks that can reduce air temps and all that jazz, just use the wind when it blows to pump water up to a small tank (maybe a secondary sump) and have it flow from that tank at a regulated rate, i like it

so you basically have a fish tank in a mid level setting, a sump tank lower than the FT to hold overflow from that and give the windmill something to pump FROM and the water gets pumped from that to a tank stored above the FT, where it is then released into an ebb and flow or constant height GB
the filtered water then flows to the FT and cause overflow to go to the bottom sump tank, starting the process over again:)

That's what I was thinking. Made a new picture. Now I know absolutely nothing about windmills or pumping water with them, but that technology was developed a while ago and I don't see why it wouldn't work, as long as certain things were considered in the design first.

that is exactly what i was thinkin, thanks for the pic:)

and in having two sump tanks you open possibilties for more food, having fish in FT
freshwater lobsters in one sump tank and mussels in the other...

The problem with the windmill is the size of tanks required. We need 1000lph, which is 24,000L per day. So, if you want to store enough for a few calm days, you're looking at needing 100,000L storage. For the cost of a tank and windmill that big, I can buy several solar systems that can pump 1000Lph.

Abe Connally wrote:The problem with the windmill is the size of tanks required. We need 1000lph, which is 24,000L per day. So, if you want to store enough for a few calm days, you're looking at needing 100,000L storage. For the cost of a tank and windmill that big, I can buy several solar systems that can pump 1000Lph.

Yeah I can't see any situation where it would be feasible to store 100,000L of water for this purpose. I have looked around for flow rates for windmill pumps, but am coming up short. Most windmills are designed for high head and as a consequence have a low flow rate. Since the head of the system wouldn't need to be 20-40' like a windmill, more like 10', perhaps a larger diameter pipe with a larger flow rate could be used.

I think I am going to put this on my list to R&DIY this summer. In my situation I have a suburban lot and being able to go vertical to save sq. ft. is an important consideration for me. I think if/when I do this it will have a backup system, either d/c solar or more likely a/c backup sump pump, to lift the water during those calm periods. I live in an area with a pretty steady wind, so I would only need to get through the midday/night calm periods. Also since you can pretty much always count on a morning and evening breeze and if that breeze can move enough water to get you through mid day / night you wouldn't need to store 3 days worth. But without knowing flow rates this really is all speculation.

i think the best way to use a windmill then would still be to store the energy in batteries as you would with other generators...

here's another option for low-energy fish farming - Greenwater Aquaculture: http://www.aquaponicshq.com/forums/showthread.php/3522-Greenwater-Aquaculture

Here's a snapshot for a 10 watt solar powered system:

4000L Fish tank
200-400L clarifier (basic baffles for solids removal)
500 lph pump (or less) - easy with airlift
5-10 watts of aeration
stocking rate of 13kg/m3 (total biomass 52kg, yearly production 100-150kg)

Cost (including solar system) - around $600 for up to 150kg of fish/yr

You continue to amaze me, Abe. I was going to do a "normal" system but you have proven to me the power inefficiency isn't worth it on-grid, either.

I ran across these: http://www.surpluscenter.com/item.asp?item=4-1830&catname=air

Comments? They seem cheap enough to run as a backup for on-grid, and seem good efficiency for off-grid but not sure as a I am a newb at this.

.

they might be usable, however, you have to be careful with air pumps that aren't designed for fish use, cause they can leak/off gas things into the water. This one is oilless, so you're probably ok. The air output is quite low, though, at only 2lpm.

Thanks. I was thinking CFM instead of lpm, BIG difference. DOH.

I am trying to get my grand ideas (many stolen from you) into reality. We will see if I can get it together this season....

Be really careful to have adequate filtration and aeration. I recently killed off all my catfish due to some issue of that sort. Also, be sure to have the proper testing equipment, which I tried to get away with not having......

follow the links in this thread to the discussion on those aquaponics forums. They can really help you get started, and they know more than I do.

Feel free to steal my ideas, and I only ask that you post your results on permies so that we can all see how things work. Share what you've learned, cause being someone's inspiration is one of the greatest accomplishments we can ever hope to achieve.

hi al1,

As a low energy aquaponics system has anyone tried a wicking bed? I made a little one in my apartment. (http://tkbywater.blogspot.ca/2013/01/apartment-aquaponics-revisited.html) it has one tiny fish in it and only a few spindly pea plants in the grow bed but its been working so far.

What do you all think? pros cons? is this a viable system?

i did a "wicking" system with gravel instead of soil this summer to clone plants and get some stuff started in the greenhouse, it works, and i think thats the driving principle behind chinampas but i think that systems with moving water usually produce more and have higher quality water

i think there is many valid idea's in this thread, some a little off topic like the windmill since the start was about LEAP (3-5 watts) and windmill certainly produces more than this .... green water is also good as if you separate fish from a green-water holding sump you can culture daphnia , used as live foods for smaller fish which in turn can be used as feeder fish for omnivore / carnivore fish types.... i also think aquaponics can be incorporated into biogas digestion, solid fish waste removed from a swirl pool separator ... the garden waste (vegetable scraps) ect can all be utilized ... personally i don't think aquaponics should be about "how little wattage can i get away with?" i think it should be geared more towards "How much can i benefit from the system i have in place?" using a green-water setup removes the nutrients that other plants could be using, yes it does make foods , but it also would if used differently , Murry Hallam works on a system i was taught from an early age (K.I.S.S) and the more moving parts you incorporate increases it's chance of failure... And relying on a single system is putting your eggs all in one basket ... can also be equally disastrous ... so you have to find a balance ... the best long term systems i have seen utilize a solar panel array, a battery bank (1 or more) , a pump system ,timers ,auto feeders low stocking rates, and most importantly the waste of one system being an input of another ..... this isn't LEAP but each system is under 100w's and under $1000 all inclusive (and completely off-grid) .... i'm in the processes of setting one of these up and will link a video up when i get a chance ... but if your into or getting into aquaponics , i highly recommend looking up Murry Hallam's youtube video's and doing A LOT of research before investing in it ... but they are easy , productive , less labor intensive with less water usage than convention gardening.. a definite "must" for all eager permies
P.S. i have seen people using a cream separator to remove the algae and using it in a biodigestor

Years ago, I started discussions on this topic on several forums.
Armed with scientific papers and calculations, I had the audacity of questioning the efficiency of as well airlifts for pumping as diffusers for aeration.
And to question, not the fact that airlift pumps are very easy to build, but that it is extremely difficult to build and adjust one that is efficient, more so that stays efficient.
I did so both under my name, as under my company name hygicell.
Backyard Aquaponics is one of these forums. A search will reveal my many contributions.
In all those years nobody has ever contradicted me with facts.

TMHO, there is only one vitallly important factor in AP: oxygen.
Fish can go for weeks without food, plants for days without nutrients and for hours without water (or days, if the media have water retention qualities).
But take away the oxygen, and fish will die almost instantly, so will most important bacteria, and plants will quickly wilt.

Highest competitors for the fish regarding oxygen are the nitrifying bacteria that colonise the solids.
So fast solids removal out of the fish tank is primarily essential. If possible, fast removal out of the whole system.
Next competition comes from plant roots, also needing oxygen.

This implies that, though combinations are possible, fish, and filtering system, and plants, should better each be in their own separate container.
It also means the water must be carried over the rim of at least one of these three (two can be combined).

As water tends to naturally strive for oygen saturation, aeration is all about exposing as much water surface to air as possible.
So we need a pump, preferably an energy efficient one, both for pumping and for aeration.

Forget diffuser aeration:
It is only efficient in two setups: injection at over 7 m depth, or injection in counterflow to the water.
In all other cases contact time and surface of the bubbles with te water is too short.

And forget airlift pumps.
The fact that airlift pumps need to transform electricity first into air movement then into water movement,
and that each tranformation means energy losses (transformed into sound, wear, temperature, pressure, resistance) makes it clear that hopes are low for them to perform.
The fact that air can be compressed, which produces heat (= extra temperature loss) is extra inconvenient.

Positive displacement pumps (i.e. a piston pump) can reach efficiencies of 90%.
Piston pumps are expensive, complicated (valves), and need maintenance.
Other positive displacement pumps are peristaltic pumps, gear pumps, worm pumps, etc...

Centrifugal pumps are extremely simple: a spinning impeller on the motor's axis does the job.
Good industrial centrifugal pumps with hydraulically designed impellers reach 60-65 % efficiency.

For over 5 years now, I have calculated the energy efficiency of just about every pump I laid eyes on in Aquaponics (mostly centrifugal aquarium and pond pumps),
the results are shameful.
Very predictably, if you just take one look at the poor design of the impellers: a plastic cross has no hydraulic properties at all.
Improving on the design of the impeller could change a lot.

But then there is, to my opinion, the ultimate solution for AP:
a propeller pump: it is a positive displacement pump,
but the slip of the water through the propeller makes it perform best at low heads
which is exactly what we need.

There are no small propeller pumps available. Only huge industrial ones.

But now there are these new powerheads and wave makers for saltwater aquariums: they are equipped with propellers
I have ordered a number of them to which I can attach a tube without too much hassle
Maybe next week I can start experimenting

greetings

Frank

that's just the thing, Frank. Look at the efficiency of what's on the market, and airlifts win hands down. Not only are they cheaper, they are several times more efficient than similar sized and priced water pumps.

Don't forget that by using airlift, you are accomplishing 2 functions at once - moving water and aeration

Abe Connally wrote:that's just the thing, Frank. Look at the efficiency of what's on the market, and airlifts win hands down.
Not only are they cheaper, they are several times more efficient than similar sized and priced water pumps.
Don't forget that by using airlift, you are accomplishing 2 functions at once - moving water and aeration

with all due respect, Abe,
but, though I tried elaborately to explain, you seem not even to have read half of what I wrote:
airlift pumps are neither efficient at pumping nor at aeration
TMHO they are no more than an illusion, a dream we desperately cling to because they seem so easy to build
I don't know everything, but I will not take your word for it that they might be efficient at either task, based on your impression
show me evidence, numbers, calculations or theories from scientific papers, anything, I wil study them in ernest like I did before
then show me where to find instructions on how to design an efficient one
so far nobody did
friendly greetings
Frank

You missed the little detail of ON THE MARKET.

I agree that airlift pumps are not that efficient, it is just that everything else is ATROCIOUS.

But now you have me thinking about prop pumps. It would not be very hard to build a prop pump that fits a 1 1/2 or 2 inch pipe and could be placed side-by-side with an airlift at test real world efficiency.

I am an engineer and learned REAL QUICK that books and lab results are a starting point but not a reliable indicator of real-world results.

I didn'n mean to offend you, Abe
but I would have thought that the explanation of two transformations of energy necessarily must lead to excessive loss of efficiency
would have convinced you as an engineer of the seriousness of my approach
it is the one thing that made me calculate pump's efficiency in the first place:

knowing that pumping, which is moving, solids from A to B is more efficient than fluids, fluids more than gases

to make amends, please find attached my aquaponics calculators (it is a quite elaborate work of 8 years, still in progress)
Ooops, that doesn't work, it is an .xls file and is refused, so send me your personal mail address
Ooops, and only now I notice that is is not Abe, but R. Scott who replied
send me both your addresses

amongst other interesting ones, for you tou enjoy with an invited critical mind
there is a tab to a pump efficiency calculator with a list of pumps and their calculated efficiency
based on the (often questionable) data of the manufacturers
with almost everywhere links to the source

and no, I did not miss the little detail
not everything is absolutely atrocious, though most of it shamefully is, as far as the small pumps we are interested in are concerned

still airlift pumps are worse, much worse
and those that I found (again unreliable) data on, came from scientific papers at that
I had to dig very deep sometimes

and nowhere any directions on designing an efficient airlift pump
except maybe somewere a horrificly complicated one

I have 40 years of experience with pumps

I have learned real quick that what you see is often not what you get
and what is promised is almost always NOT what you get
never take things for granted
stay sceptic about data provided by manufacturers, even for the industry

in Flemish they say: "meten is weten", "to measure is to know"

airlift pumps and diffuser aeration are a hoax

greets

Frank

Frank De Block-Burij wrote:[
show me evidence, numbers, calculations or theories from scientific papers, anything, I wil study them in ernest like I did before
then show me where to find instructions on how to design an efficient one

1200 lph (320 gph) on 5 watts for under $40 (built in less than an hour):
http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=11703
http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=12019

show me another pump that can match that.

there are many more on that forum. Also, please read this thread: http://www.aquaponicshq.com/forums/general-ap-discussion/6994-low-energy-aquaponics-leap.html

It has significant details on airlifts and designing and building them.

Abe,

it is like in any other love story: confidence is a very nice thing, but checking is often better

so sorry to disappoint you:

pump effect (in kW) = head (in kg/cm²) * flow@head (in l/min) / 600
pump efficiency= pump effect / energy input

I only checked the first link: http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=11703
2" = 0.051 m
head = 0.0051 kg/cm²
flow@head = 1200l/h = 20 l/min
energy input = 5 watt hr

pump effect = 0.0051 kg/cm² * 20 l/min / 600 = 0.00017 kW = 0.17 watt
pump efficiency = 0.17 watt / 5 watt = 0.034 = 3.40 %

this in your impression "efficient" airlift pump wastes 96.6 % energy
it is not worthy of your confidence nor of your love

All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.
Arthur Schopenhauer

Frank