Backyard Aquaponics
A place to discuss aquaponics

that is what you get here, Bree,
the tiniest ripple in the water soon turns into a wave and later into a tsunami of helpful people with only one concern: to addict you to Aquaponics

as will be confirmed by many members:
probably the only way to save your marriage is to seduce your partner into visiting this forum so we can all join forces to make him an addict too

we can be very convincing

greetings

Frank

Join the club! A growing addiction....

A main purpose of using a sump tank is so that you can keep your fish tank levels relatively constant even while flooding a large amount of grow beds.

I'm highly in favor of the CHIFT PIST set up (Constant Height In Fish Tank Pump In Sump Tank.) If you set up so the Fish tank is higher than your main grow beds so it can simply overflow into the beds and then the beds auto siphon into the sump tank where the pump is. Or it could even be done with a stronger pump, a timer and slow drains on the grow beds. In these set ups the only big drawback I can really pinpoint is the need for a rather large sump tank.
Major benefits I see include;
1-keeping the fish tank level pretty constant
2-solids go directly into the grow beds
3-solids do not get blended up by the pump
4-pump is in (or drawing from) a rather clean sump tank and you avoid the constant pump screen/trap cleaning.

I'm running a continuous pump system with auto siphons or other automatic draining techniques on the grow beds. My large fish tank is in ground and the lowest thing in my system. My large fish tank level fluctuates quite a bit. I'm probably near a 1.5:1 growbed:fish tank ratio. I am probably quite close to my max stocking density. Air doesn't seem to be my biggest issue. Solids do seem to be my limiting factor at this point. I really wish it was easier to re-work my system into a CHIFT PIST system.

+1 on your remarks, TCLynx
let me add a few (there must be more):
the ability to completely drain all your tanks
the ability to move your whole system to another location
no holes to dig
the ability to put everything on a concrete or other solid floor

I am a bit puzzled by your fishtank/growbed ratio: is that volume or surface
and you don't mention the density at one recirculation per hour
do you disagree that density can be increased (within limits)if you simultaneously increase recirculation and growbed volume/surface?

frank

You have such a generous attitude in sharing from your experience TCL. I hope it comes back to you in many, many ways. I have thought this time and again. It is because of you that I went CHIFT PIST and I am very grateful to you for that. I would not have had the confidence to do so without all your direction and input.... simply words.... but I do thank you.

+1 for this comment, Chelle
let me second it
frank

just some addiction symptoms, Bree
the good news is that they won't go away, only increase
... or is that the bad news?

what is a flowform?

frank

Oxygenation method... duplicates a cascading rocky stream ...

http://www.livingwaterflowforms.com/var ... wforms.htm

http://www.californiaflowforms.org/prod ... nFold.html

http://www.waterfeaturesforgardens.co.u ... y.asp?id=1

thanks Rupert
confirms my theories

frank

From GB... through flout....through flow form... down into fish pond. Excellent.

I was told I should use flow-forms in my AP system by a neighbour recently but didn't know what he was talking about! Never got around to researching it till now..... and so glad I did! Thanks for the links Rupe!

here is my small footprint version of it:

will post it in the sketchup thread also for further examination

Frank

Frank-
An observation-

The proposed method of measuring the flow from the air pump is going to understate the water movement. OBO said that he had a 1m circle of bubbles, you said to use that to divert flow from it over the side to see how quickly you can fill a bucket. The circle of bubbles is moving water, but not necessarily in a way conducive to such a measurement. If the purpose were to have an airlift pump, that would be a valid measurement and comparison, but since the apparent purpose of OBO's air setup is to keep the water moving, and put DO into the water, you would be comparing apples to oranges.

While I agree that air doesn't produce the most efficient use of power, I think it does have its place. Especially in keeping DO up in a crowded environment.

-Doug

Doug,
this thread is about energy efficiency
while air pumps and diffusers undisputably have a historically established place both in aquaculture as in aquaponics, only measurements or/and calculation can determine whether or not they are energy efficient either at pumping or at aeration
1. pumping: So far ALL examples of airlift pumps I have found that mentioned head, volume and power consumption have failed the test and shown extremely energy inefficient. I have found not one single exception. I am quite ready to change my opinion if only someone would bring up an example of an energy efficient airlift pump
2. aeration: ALL papers I have found on efficient aeration with bubbles speak of submergence rates FAR higher than existing in aquaponics or aquaculture. deep submergence equals high energy demands. Furthermore efficiency of bubble aeration is dependent on the size of the bubbles: only very tiny bubbles achieve an acceptable aeration rate because of two factors: they expose more surface and they float more slowly upwards (hence the need for deep submergence).
diffusers capable of producing extremely small bubbles at great depth are high tech and very expensive. and by their nature they are prone to clogging and need a lot of maintenance.
none of these conditions are met in either aquaculture or in aquaponics
these are facts or at least I have found not one single evidence against it (and I have done a lot of searches and still continue doing them)
next follows an opinion, not a fact:
I presume that pumps are much more efficient at both tasks because for the same energy input they move much more water (not bubbles), thus have the potentiality of exposing more water surface to air surface on one condition: in a well designed system where all possibilities of passive aeration are exploited.
open gutters, flow forms, cascades, turbulent flow versus laminar flow, counter current ventilation, etc...
I know I am sticking my neck out by stating this as it is against general belief
a lot of the first people that dared to suggest that the earth is round were beheaded or crucified.
no doubt there will always be a place for airlift pumps and diffusers
just like there will always be a place for pen and paper while we all know that computers are much more efficient
the only advantage air driven systems have is that they SEEM easily applicable
but don't let yourself be fooled by impressions: adjusting an airlift pump for best performance is very complicated.
the diffusion of bubbles over a 1 m wide circle shows exactly that: the diffusion of bubbles, not of any substantial amount of water
just like to the eye you might think that a lot of water is moved but how can you tell? your eyes cannot ignore the bubbles that fool your impression
please contradict me
it is my honest opinion that airlift pumps and diffusers have no place in a system that pretends to try to be energy efficient.
greetings
frank

If we accept all you say Frank... then the question becomes.... to acheive the level of aeration required employing the means you outline above.... are water pumps energy efficient in terms of operating cost?

Pumping water to xxx head to utilise the means outlined and acheive the required aeration obviously comes at it's own energy cost....

Does the cost of energy required utilising more efficient water pumps to acheive the same oxygenation outway the cost of energy utilising less efficient means?

For example... using electric driven paddlewheels to aerate ponds, while perhaps inefficient in "mechanical" energy terms.... less energy efficient in terms of energy cost as opposed to the cost of running water pumps to lift/pump water to the types of aeration devices you prefer....

And would they in fact acheive the same level of oxygenation?... perhaps, but to aerate a pond by those means would require an enormous amount of water movement I'd suspect... and associated energy cost...

How do you compare and determine the efficiency of one against another?...... perhaps there's a scalability limit that applies?