Backyard Aquaponics
A place to discuss aquaponics

I guess I don't understand an open loop system at all. In the end what I'm trying to do is grow veggies and have fish in a system that is self supporting as much as possible, If I had fish that ate veggies I guess id be there all ready, but as is I have to feed the fish something ie worms and guppies. Now the worms eat table scraps and junk mail (all a good thing) so that loop is closed. The guppies on the other hand currently eat fish flake and a few other purchased feeds, if I can close that loop by growing their food then I would be a bit happier.
An open loop to me is just too vast ie the whole earth and we havent done too well with that so far.

Greenedo, the only problem with this type of set up would be that the water would only contain ammonia when it left the fish tanks. You really need a recirculating system (through grow beds or bio filter) to convert the ammonia to the nitrates that the plants require for growth.

GD if you think aquaponics production cant compete with hydropnics and aquaculture have a look at this site: http://www.hydroponics.com.au/back_issues/issue43.html
From current information I have these guys are producing 600kg of Barramundi a week along with 20 000 lettuces per month!!

Pity its not a closed system?

I am wondering if you were able to set up a series of ponds and growbeds if you would be able to use this for AP. We have a place up int he village at the intesection of two rivers. Its on a hill and has lots of running water. We also have 4 ponds set up mostly to raise shrip. I was thinking if converted some ponds to growbeds or added some growbeds in it would make a simple solution for growing vegtables. Now don't get me wrong i like the recirculation idea but how you gonna get some village guy conviced he should pump his water in recirculation when he can just tap into the river.

So now for some research. How big or how may beds would you need to convert the amonia directly into nitrate and nitirite? With our sand filters i belive the trrasformation was an imeadiatly high percent of the water that flowed through but i would have to go have a look with a amonia tester (if i could find one).

Interesting read T'man, this brought on a smile:

there's a barra farm up the coast that classes them selves as a Recirculating Aquaculture System. Have a look, they don't seem to have a specific website

Isn't the whole earth technically a closed loop system.??

Tries to be Ron.... we as humans just keep cutting and bleeding her...
opening her up.... wondering why she gets diseased (pollution, global warming)...

But Ghia by nature attempts to be self healing... the ultimate closed loop

Tecnhically, yes, the earth is a closed loop, but on such a huge scale, with so much activities and sources of contaminants, that comparing the earth with AP is useful only as metaphor.

Micro closed loops like Joels AP (the reason I am here) reduce the potential for external contamination by controlling your inputs, feed and water, in a micro managed self contained unit, with the various components, both mechanical and biological working to achieve equlibrium. Its poetry, its art, its stable and productive.

and


This is a better description of what I feel, too, than what I have tried to say. I am open to other options, but its going to have to be pretty spectacular to beat what Joel has done in such a profoundly beautiful and simple way in his small back yard.

Charlies system i guess could be open loop, water in from the river, through the trout hatchery, through a biofilter, back to the river.

He is looking at incorporating plants in the last step.

Each type of system has its merits, its not that one is better than the other, just different.

Why would charlie use a recirculating system when he has a RIVER with lots of water meters away?

oh VB,

I agree an I'll add to that with the "aged" system again, i'll bet there are hundreds of "littl 'uns" in a mature grow bed or even bio film of a fish tank al playing their part that for the most part texts simplyfy to nitrifying bacteria.

Hi Troutman,

Just for the sake of accuracy, what I said was......



When I look at the full sentence again, I can, however, see where it may have been written more clearly.

EB told me about the information that had been provided by Nick Savidov several months ago. Until I see these claims disproved, I'm happy to accept the claim for greater productivity around aquaponics.

What I found interesting (and faintly disappointing) was the following:



The only way this would be acceptable, for my purposes, was if the amount of water that was transferred was about the amount required for the lettuces.......otherwise this particular aquaponics set up is not much different to any other commercial aquaculture or hydroponic facility which dump large quantities of (sometimes nutrient rich) water as part of their operation.

Gary

Most industry (in my opinion) never closes the loop. What ever the process, waste is produced then dumped for the rest of the earth to deal with. From its begining AP does not do this and so the balance and that is its major attraction for me.
I cant control the amount of crap my employing company tosses into the enviornment, (and they all do government regulation or not) because I need to make a living. I can attempt to reduce impacts by having an AP closed system though.
Emagine the global impact if everyone had a small in home or backyard system. That's what I'm for, every home aquarium hooked to a grow bed. How simple is that!

I love that vision, John. 0-food miles and fresh wholesome food! Now if only we can affect the culture and mindset-shift that would take!!

Yet no-one will wee in their aquaponics tanks? hypocrisy?

Troutman- I was talking about attempting to scrub the water through growbeds before returning it. This would be for a setup like jtjf mentioned:
You have an unlimited supply of water and so you start with the fish pond (I see DO issues, if just using the water from a river/stream), then you run it through a series of growbeds/gravel/sand filters, returning it at a lower level to the stream.
Pros- 1- zero energy, 2- impossible to build up toxic substances
Cons- 1- Longer time to cycle, since the bacteria will never be recirculated to the inflow of the growbeds, 2- lower concentrations of nutrients, since you would only have one pass at the conversion, 3- the unknown factors that produce the P & K for fruiting may never develop, since they were found in a recirculating system, 4- you would need a higher ratio of GB/filter media than in the recirculating system, 5- the available nutrients would change as you moved down the GB/filter beds back toward the exhaust end.

Overall, while I think that the system might work, and have some appeal to the place where power is expensive, and you have the difference in height and plentiful water, I think that the cons outweigh the pros, and you would be better off having your inflow be for automagic top-up, and then use the current of the stream to run a pump to recirculate. You can have a small amount of exhaust water to feed a dirt or other GB, but you would want the majority to be recirculated to avoid the issues listed above.
-Doug