Backyard Aquaponics
A place to discuss aquaponics

The discussion cant be closed yet. I've been waiting to see a comparison of efficiencies with Jamies bicycle pump back-up system.


Something I'd like to know is the effects on water temperatures between air pumps and water surface splashing. I assume that on a hot day (>30C) an air pump will drag hot air into the relatively cool water allowing for heat to transfer into the water, thus raising the temperature of the water. However a pump of some sort (eg a simple fountain) that agitates the water surface will allow more water to evaporate thus creating a cooling effect.
My water tank is mainly covered, and with the evaporative effect I have noticed that the air above the water is much cooler than the air outside. I assume this is of more benefit to the trout, helping to keep the water temp down just the slightest bit.?? I also assume that having an airpump in a warm spot (eg inside a black metal box in the sun, provided it didn't get too hot and melt) would be a simple way to heat the water.
Am I assuming too much? Would it really make a difference?

This is my experience in other areas of life. Empirical data will often enlarge understanding enough to improve calculations by adding previously unknown variables. A truly scientific mind will be open to this. And remain open that all variables may still not be understood. Not to do this is to be dogmatic.

Experience speaks. We use what we have to get the results we need. Calculating our way out of using something on a scale of efficiencies is sometimes opening ourselves up to a very definite empirical loss of life. Expensive. In this case the scale of effiencies needs be calculated together with the scale of economies. Can an outsider state emphatically that there are then no further variables to be considered? To always assume we know all the variables in each particular set-up is arrogant. Direct and personal experience is invaluable and has been known to disprove clever calculations.

In 1934 the French entomologist August Magnan argued that, according to the known laws of physics, the bumblebee shouldn't be able to fly.

From the New York Times


This forum is a wonderful learning experience. Even when we disagree. Sometimes especially then!

Respect for fellow APers is not least best learned. No matter how clever my solution may be, if I communicate disrespect I will not be heard.

You still trying to solve the heating cooling thing KE
Stick an air pump in a black box in the sun and I don't think it would last long.
BTW Compressing air generates heat at the pump, when the air expands it cools.

Has anyone used mist makers in there FT. I ordered a small one to use in a NFT tube to help get roots to the water. If it could aid in evaporation it could have a temp effect. Not a big power user either.

Duff
The transducers tend to crap up, well the cheap ones, look really cool though
Cavitation produced can stuff up bacteria though, possible water sterilising aid, perhaps.

Oh! Mist produced is one of the highest evaporative cooling methods out (subject to conditions, of course).

nothing in any of my posts has ever shown me to be closed to either empirical data nor to new or not completely understood variables.
so I reject this "dogmatic" label.

quite the contrary: I have always asked to help me in my search for new data and new variables, whether they would confirm or contradict my line of thought.

to hang on to a general belief and systematically reject the mathematics that show that a subject is at least susceptible to a critical approach,
THAT is dogmatic.

mathematics have shown me that all airlift systems (found so far) are wasting energy
but that is not the only thing mathematics have shown me:
the other surprising fact that has come out through mathematics is that most small pumps are performing very poorly too
I was shocked.
To my knowledge nobody has tried to calculate this in the past.
The benefits and necessity of mathematics are hereby indisputably proven.

I will even add one argument in favor of air systems:
Simple - yes
Effective - yes, I never discussed that, the only thing I questioned is whether you can generally label some device as effective if it's effectiveness is limited to one priority and all other side effects are neglected.
Efficient - no, we seem to agree
Cheap -?- definitely only if you choose to ignore the price of a good blower and the annual exploitation costs. I believe these to be extremely important variables that should not be systematically neglected. That is marketing tactics: to emphasize benefits and to neglect or abscond negative elements.
so, my conclusion:
Cheap? - NO!, definitely not!
Easy to adjust? - to visual result, yes, to efficient result, no.

The "fact" that your fish - All the fish! - would be dead right now if you did not have air being added via an air pump
is not a fact but an assumption,
and does not in any way contradict that there might exist better, cheaper, more efficient methods to avoid being a serial fish killer.

the "experience" that trout were happier with a 20 watt diffuser than with a 60 watt pump proves nothing either:
I have always stated that any system must be well designed for it to function properly
which does not necessarily mean complicated
by their nature, diffusers will bring cooler bottom water to the top, which is excellent
simply replacing the diffuser by a pump is not enough: the pump must be at least equipped with either a suction pipe to the bottom of the tank or a stand pipe to the top of the tank and some device to spread that water over as thin a layer as possible, preferably with ample fresh air access to both sides of the layer
else the friction of the water will make the pump lose all it's efficiency not at moving water, but at exposing that water to air

it so happens that in every AP system there is a pump needed to bring water from the growbeds or the sump to the fish tank or the upper tank
I have explained many ways in which you can take advantage of this pump for better aeration

that is what I constantly do: share my experience and lay it next to yours
and try to find out why experience shows what it shows and what the fundamentals are
and try to calculate them so these experiences can be replicated
for that I have at my disposition only the known variables
I am constantly inviting you all to point me to new variables.

Not calculating is worse and more expensive.

efficiency = economy. Always.
What you mean is that priorities should come in the equation as well.

I never do that and have shown never to do that.
I reject the outsider label: where pumps and hydraulics are concerned, you are as much outsiders as I am where growing fish and vegetables come into play.

even where pumps and hydraulics are concerned I have often declared not to know it all, even to know little.
So I definitely reject the label arrogant.

calculations have at least as often proven that the conclusions drawn out of direct and personal experience were wrong or had other origins and explanations than the ones assumed. Impressions should always be put to the test. Mathematics can help with that.

I absolutely agree.
I have a tendency never to suspect people of bad intentions.
Even to ignore all the obvious signs that may point to this.
I invite criticism as it is a way to better understanding.
but I dislike it when the player is played instead of the ball.
In technical matters I am outspoken and straightforward.
that is often perceived as arrogant or aggressive.
I have on numerous occasions implored people not to consider it like that.

to show you how easily written words can be shocking even if not intended:
Though undoubtedly not wanting to do so, Chelle, as I consider you as a very good friend and there are many posts and private mails that confirm that, still I could interpret your post as extremely condescending:
you have consecutively called me dogmatic, an outsider, arrogant and, last but not least disrespectful:

I most of all reject the label of disrespect insinuated in these sentences:
even if someone continues to contradict me (which I invite), but not with solid arguments (which I invite)
still I have always shown him/her the respect of reading both what he/she wrote and the links he/she pointed to
not in search of items that sustain my point of view, but in search of data that may contradict me so that I have to adjust my line of reasoning and so I can learn from it.

so let me put a vote to mildness:
There is such an immense amount of goodwill on this forum

please accept me for what I am and for what I assume you all to be: generous and helpful persons who are trying to repay what they have received here by adding their knowledge and experience

peace to all

Frank

My point – taken in context – is that calculating on one scale alone is inadequate.

Should all the variables of a particular problem not be considered…. And they differ from site to site …. Perhaps simply because fiscal capabilities alone may differ….then the calculation is not helpful. You may be able to give me the best advice on efficiencies Frank but if I cannot afford it it will not solve my problem. If I can keep my fish alive with what is available to me, despite calculations against efficiencies then it would be foolhardy not to do so. We use what we have to get the results that we need


Efficiency DOES NOT always equal economy. You can apply increased efficiencies to any problem with very expensive technology…. Both to install and to maintain.
No. What I meant is that not just one set of calculations is necessarily adequate in solving a problem.

The rest I will not debate here. I have send a PM.

taken in context, there is no disagreement on any point , Chelle:
calculating on one scale alone is inadequate.
I agree.
That is not what I'm doing.
all the variables of a particular problem should be considered.
I agree.
That's what I'm trying to do, but I don't dispose of them all.

the effects of local circumstances are as good as irrelevant when it comes down to bare calculating efficient growbed and fish tank surface distribution and accessibility versus greenhouse surface: with the same physical circumstances (orientation, surface, inclination) the same optimal setup regarding those elements will be optimal wherever you put it.

What can differ are the priorities: wanting to accentuate either fish of plants or accessibility or rabbits or hens, or ... , or even looks and architecture can and will change everything.
and the local availability of materials are important too: It goes without saying that in your case the availability of good river sand at no cost is an enormous asset
still you have to find the way and method to put this to best and most economic and most flexible use possible, whatever your priority
but these must all be outweighed against one another
the final decision is yours

this boils down to communication: no "outsider" can fathom your priorities unless you communicate them

If you can keep your fish alive with what is available to you AND with the aid of calculations PRO efficiencies then THAT would be foolhardy not to do so.

taking ALL variables into account by definition leads to the conclusion that efficiency always DOES equal economy.

so we seem only to disagree on the necessity of calculation
I believe it a necessary way to compare
I believe it the only way to compare
I believe it an easy way to compare

I am willing to give you all possible help (within the limits of my knowledge) in setting up spreadsheets which will allow you to objectively compare, as the subject interests me immensely.
I am expecting and welcoming harsh criticism on these spreadsheets.
I want to continue learning.
That never ends.

Frank

heh

The verbosity in these threads is amazing I should have gone to higher schooling

Frank, I cant remember if you have actually stated the *most efficient* (purchase cost, running cost, maintenenace cost) way to aerate.

I want to have something seperate to the AP part of the system to aerate the water - obviously airstone are not the most efficient way (I still like the bubblyness though ).

Going by you previous posts, a pump running into a gutter that overflows over the edge in a long thin film seems to be your preffered method - what would the pump ratio need to be compared to tank size? 10,000 litre tank = 5000lph pump or what? What sort of airstone arrangement would be required to make the same amount of air?

Remember, I want the aeration to be able to provide 100% of the oxygen requirement, seperate to the AP system.

This is so if the AP system fails, there is enough oxygenation for the fish to survive until ammonia takes over. I want to make the next part of the AP system as efficient as possible - while maintaining 100% fish safety. This means two seperate means of aeration.

Ta

+1 OBO
This is what I want to be able to calculate. I may have missed it so please point me to such calculations. I AM looking for the most efficient way to proved air for my next system. If I can do it with a thin film method I might want to, but if it cost hundreds of dollars in gutters and takes hundreds of feet then its not a realistic option and its back to pumping air into the water, paddle wheels, or air pumps.

Sorry. Especially to Feintstar.
Frank and I got a little carried away with our wrangling....
We have taken it off forum. Giving each other a thorough bopping.... thoroughly enjoying it!.... and coming out smiling.
What's not to love about BYAP!
Thanks for your PM Frank. I am rushing and will respond when my day has calmed down. Give it the time it deserves. I enjoy debating you.


I am looking at flowforms to do this. ..... I have positioned an extensive one between the GB flout and before entry into the FT in my CHIFT PIST design. I will be giving a 1 meter drop between to be able to effect this. It can be as simple or complex, as utility or as artistic, as you prefer.
Frank uploaded his very efficient design of a flowform in the Sketchup components thread started by EB.
Here are a couple of sites that give the idea clearly.
http://www.flow-forms.com/
http://www.stohans.com/shop.cfm?categor ... goryID=456

Ozzie, I have come to know you as one of the most helpful people on the forum and we have exchanged many friendly posts, trying to find solutions and comparing each others experience and insights.
and I have enough sense of humor to accept a friendly challenge from a friendly person.
So I take it you are not setting up a trap for me.
I love the bubliness of diffusers too, but I fear they are conveying a false sense of security, or maybe a right sense of security at a too high a price.
Please don't ask me to show you how to calculate the exact volume to recirculate:
just like there are no formulas to calculate the necessary diffuser surface or air volume and air pressure needed to achieve good results (this is all empiric), I have no knowledge of formula on how to calculate recirculation rates except for the ones I found on the net that deal with oxygen needs versus feeding rates and which I have incorporated into the spreadsheets I have posted some time ago that you can find here:
http://www.backyardaquaponics.com/forum ... f=1&t=4150

to come back to your question(s): I cannot and will not tell you what to do, as the final responsibility is and stays yours.
but, now that it seems established that we think the same about air system's efficiency, I welcome your offer of help in trying to find solutions.

So I will tell you what I plan to do myself:
first: I use 1000 l IBC containers filled to about the 800 l mark for each individual system
the main pumping/filtering/aeration of all my systems will be like posted in my "low head aquaponics" drawing.
http://www.backyardaquaponics.com/forum ... f=9&t=4293

that should ensure the integral health (aeration and biofiltration) of all my fish to at least the densities normally accepted as safe in AP systems.
so under normal circumstances, no other systems would be needed.
the pump timer is now programmed for runs of 10 minutes each hour by day, by night every 2 hours (the timer only holds 20 programs)

But for safety in case of power failure, a backup system should be provided.
I propose to achieve this with a very small 12 V 8 Watts backup pump ran from a battery combined with my design of a high gain passive aerator:
http://www.backyardaquaponics.com/forum ... =a&start=0
a NC relay (which, when the power fails, automatically returns into it's Normally Closed position), will make this system kick in each time power to the main pump is cut out.

for full safety, the problem of ammonia buildup must be coped with too
ammonia peaks are highest just after feeding
to avoid them as much as possible, I want to spread feeding over the day
for that I am thinking of an automatic feeding system that is triggered by the main pump being switched on, so peak aeration will coincide with feeding
a small amount of food will be added each time the main pump kicks in
which means that feeding will stop when power fails
this is one side of ammonia control

but to my opinion it is not safe enough

Each of the four lines (NFT, small growbeds, one big growbed with the media in baskets, floating rafts) in my setup is equipped with an upflow floating bead filter between the fish tank and the growbeds.
that filter serves as settling tank as well as each hour there is pumping for 10 minutes and settling time of 50 minutes
settled solids will be automatically pumped out just before the main pump kicks in

So the small 12V pump will be located in a compartment in the beads so that it recirculates biofiltered water to the fish tank

these are the principles

now back to building
the first two lines (NFT, small growbeds) are as good as finished
I would post pictures, but I can't find the cable for my camera (shows how organized I am)
now my priority goes to finishing the greenhouse covering as winter is nearing

Frank

Nice to see your ideas "fleshed out" and brought together Frank....

I have a couple of questions... but before asking them, I was going to suggest that as they're specific to "your" system... that perhaps it would be best to start a thread of your own in the "members" section... so that anything pertaining to your system is in one place...

I plan to do so, Rupe
and will copy and paste what I wrote onto that thread

but that would take some time to do it thoroughly
and for now my absolute priority is protecting what I already have from winter
so I must build instead of post.

I have spent a lot of time answering questions about my attitude on this forum
on average each post costs me more than one hour because I have the constant feeling of walking on eggs
the one I posted this morning took me 4 hours to write
you must realize that English is not my mother language

I hope that this kind of discussions can be closed now and considered history
I am counting on you and others to defend me whenever my language skills fail to convey anything else than a wish to be helpful

Frank