Backyard Aquaponics
A place to discuss aquaponics

Journeyman.. commercial aquaculture... and commercial hydroponics ... are totally based on control of, or greatest level of mitigation... of inputs... so that a consistent optimal growth output can be achieved...

Designed to remove/mitigate the "natural" chaos factors...

And that's one of the reasons why media beds.. and single "closed loop" design... have no place in commercial aquaponics (along with a few others)....

Nobody can definitively know, monitor, or control... the unknow, unquantified... biological processes taking place within them... and/or the effect that such biological processes may have on either the fish or the plants...

Neither commercial aquaculture... or commercial hydroponics... want to have ANY unknown, or uncontrollable biological processes in their production system....

Those that are, and known... can be utilised, monitored.. and adjusted either for benefit, or control....

ie... nitrification, pH adjustment etc...

Media beds were abandoned as commercial aquaculture filters... and commercial hydroponic plant production methods... decades ago... and for very good reasons in both cases...

Haven't we all said... from day one... that aquaponics is a combination of aquaculture and a hydroponic means of plant production...

Why do we cling to, and keep insisting... that it's anything more than that... that is somekind of spiritual voodoo...

Whacking the two together is single loop in the backyard.. works bloody brilliantly... doing so in a "commercial" system.. is a financial disaster waiting to happen... IMO...

While the physical structures of AP respond well to formulae (although even there we get some weird results using the same equipment as others - just look at the ongoing questions about siphons) AP IS a natural system when we talk about the mechanisms which make it work.

In Hydroponics we see a chemical attempt to emulate our modern farming methods - try to emulate what is needed by adding it all in. As a result, in farming at least, we are seeing reducing nutrient levels in our veggies, so, for example, even if you only ever buy fresh carrots, you are still getting less nourishment from them than someone back in the 1930's.

The chemical transaction we use in AP are very distinctly a process of Nature and we mess with them at our peril. Yet formula for them don't seem to work very well, or we wouldn't have threads about issues with cycling. At present, until we know more, that level of AP is more an art form than a science.

Mind you there is still a lot to learn re structures we use as well - the furore over Paul from Earthan Group's design for his community project is evidence that we are still discovering working solutions. We can use formulae to work out how big the pipe needs to be, or to evaluate whether our flow will work with x pump, but we are still finding new ways to take the bacteria products and turn them into food.

And none of our AP systems are closed systems, no matter how engineered they might be. What we try to do is minimise the input and variables as we emulate nature's method.

I'm not suggesting that chemical processes aren't occurring, or unknown.. or that they're not "natural" Journeyman...

The reason that "issues" seem to reoccur.. and that "AP is more an art form than a science"...

Is because most people don't know, or apply the science... and in a backyard context... the don't need to know to any "enth degree"...

Sadly, the advent of "commercial aquaponics"... has been driven by those that either have no experience in aquaculture, plant production... or both... and have either been unaware of the sciences involved in both, or have chosen to totally ignore them...

There is a difference between backyard aquaponics... and commercial aquaponics....

From a commercial perspective... it IS entirely the case that it can be disgned as an aquaculture system.. and a hydroponic system... with a shared commonality of water and nutrient adjustment accordingly...

Look to people like Losordo, Timmins, Rakocy, Savidov... Paul etc... (& Ryan )...

Ignore the "commercial" models perpetuated by the Friendlies & Hallam et al... separate the two commercial loops.. design/monitor and adjust accordingly...

Fair enough.

BioAqua seems to have nudged his way into a commercial venture - the 'resilience' mentioned earlier seems to be working for him. As near as I can see from his posts, he isn't using training or selling systems to augment his success, but rather developing a variety of outlets and value-adding to his produce.

And even so, his threads make it clear he is making mistakes and having to adjust as he goes, learning from mistakes or attempting to thwart the vagaries of nature as best he can. I'm not sure where a formula might help him - it seems a seat-of-the-pants situation for most of it.

Maybe one day there will be a dozen formula to cover all contingencies, but in AP as a developing activity, it appears that we are still learning the parameters that might influence the variables in such equations.

And I'm not disagreeing... if it makes more sense or it's more comforting...

Replace "suck it and see"... with... "a seat-of-the-pants situation"...

You guys are the shiz niz. I think I will keep my aim on backyard aquaponics for some time to come.

I too believe AP is an excellent hands-on system that can be used to learn science and math applications in agriculture. The opportunities for integration of math, science and technology in both creating and utilizing the system are limited only by the imagination of teachers and students.

The debate over the small versus large holders for AP is often non-conclusive. The large holders commercial AP produce fish and plants for the market whereas the smallholders‟ AP is for the family and local consumption. All systems are different and a device under test will perform differently in all of them.

Have you heard of micro-commercial enterprises? Some farmers sell 5 pounds of fish or plants, even less a day, to market; they are sustainable businesses too. Commercial AP systems can be started off as a small scale operation. Why not? Why do you want to look at commercial AP ones as a huge investment, big budget projects?

Start small, think possibilities, reach a little further, learn from all your experiences and grow as high as you want to take it... is my mantra.

Back to the subject,

For example, let us have a look at one such ratio mentioned in those (Rakocy/Savidov) research results...

The component ratio: Volume of fish tank to Volume of grow media - 1:1 or 1:2 or 1:4 or... you choose it.

Variation in this ratio depends on type of grow media, fish species, fish density, feed rate, plant species, etc. For the greens such as lettuce, spinach, and basil, etc., the square footage of grow space can be increased to four times or 6 times but for hardy plants we need lesser space. If you have decided to have water hyacinth for water quality management or algae growing as Tilapia fish feed in your pond, all the above equation collapses. What say you?

Kind of......but no.

Much as I like to challenge the formula concept of AP, the grow media question is a surface area versus cubic volume issue, the fish density and species has little to do with it as opposed to amount of food per day and the variety of plants has, near as I can work out, nothing at all to do with success. (apart from do you have enough of them)

So... Variation in this ratio depends on fish species (as in how much they will eat) what the food is and how much is being fed, and how big the GB's are compared to how many fish are in there. All the rest is what we come on here to talk about. i.e. what design uses the available nutrients the most efficiently... which fish suit a given environment etc.

The species of fish is really irrelevant.. the food being fed will probably be species related... and/or stage of growth related...

If you know the basic composition of the feed.. especially the protein content... the amount of ammonia and wastes generated for the daily feed rate... is easily calculated...

Thus the volume of filtration can be determined... according to the rating of the media utilised...

Um... no the species is NOT irrelevant. Some eat any time there is food and some don't. You are making a point (maybe - it is hard to tell) that was already being made in my post, but making it seem like you are disputing my post.

Did you bother to read the post above mine or did you just want to take issue with me personally? I quoted it so you SHOULD have been able to read it. Maybe you could be more clear as to what it is in what I said that you take exception to? Because as it stands it looks like you are saying what I said in a very disagreeable tone.

The media has a lot less to do with it, unless you want to begin arguing for external to GB filtering? Or maybe you want to argue for the various surface area to volume possibilities in media? (in which case go start a thread)

I made it quite clear what I was saying; you choose to pick a little section of my post to be disagreeable about.

That's fine... provided you do not mind being seen for doing that - being disagreeable.

You do not have to argue with people to be recognised as a significant contributor to BYAP - you could just rest on your laurels.

Actually, on a regular basis, across many threads, you do like to disagree. Even when you agree you like to post as if you don't. Vis-a-vis the BioAqua posts. A member who has a viable commercial operation comes under attack because some people don't like the way he words things.

Here you decide to be pedantic about the species of fish in spite of the fact it was covered in my post anyway. Given it is apparently fine to talk about the poster instead of the subject, I think you just like to pick holes in everyone else's views to boost your own.

Seriously mate, give it a rest and if you can't find anything real to disagree with, just click away and let the thread run until you can disagree with it in some kind of realistic way that isn't so patently fake.

Too many things to enumerate.. let me talk about amount of food per day in our case... we are giving 2 kg food per day, slowly increased to this amount over the past 2 months.. this is what they eat to satiation. 4000 fishes, it is a polyculture... 5 different varieties... tilapia and carp species plus some snakeheads... Plus they eat several unseen things such as filamentous algae, those phyto/zoo planktons grown in the pond water because of our supplemental manuring... I could see tilapias nibbling on the pond walls most of the time. So, we can not calculate the actual amount of ingested food.

Our success story... not that far... we will have our first batch fish harvest in another 4 months... we will know then. We started harvesting plant products, not sold anything to market yet.

All of these statements are wrong IMO... please have a look at my reply to Jman and tell if you can calculate the amount of feed our fish is ingesting on a daily basis.. You know the specs of our pond. You can not base your filtration or rate the media based on that.

What the?...

Journey I post to address the content of the post... or part of a post...regardless of the author...

Perhaps I wasn't clear enough...

"The ratio" is determined by the capacity of the media to process ammonia and wastes produced by a given feed rate.. (maximum feed rate at desired harvest size)...

It doesn't matter what the fish species is.. or whether or not they might eat from one day to the next....

You have to cater for the maximum capacity required... even if you never reach that level...

And the media does matter... vs "various surface area to volume possibilities in media".. as each media has a specific surface area/volume rating

The Biological Surface Area (BSA) of a system.. is the amount of surface area inside your system that bacteria can live on... BSA in the total number of square metres per system.

To determine the BSA, you need to determine how much Specific Surface Area (SSA) is in your system. SSA is measured as the number of square metres per cubic metre (mtr2/mtr3).

This is the total amount of square metre area of the volume of media you’re using.

You then multiply the SSA by the VOLUME of the grow beds... to get the Biological Surface Area...

Every media is different... and many media have been rated.. on this basis...

And all commercially available aquaculture filter media is rated as a capacity to process xxx amount of feed.. on the same basis

Nate Storey list some values for common media in one of his blogs...

http://verticalfoodblog.com/biological- ... quaponics/



Journeyman.. I went back and checked through Bioaqua's thread.. and apart from a question regarding understanding his design flow... I didn't really post anything.. let alone anything negative...

Yes, recently I raised some points about his design.. that I thought were perhaps negative... but that was within a discussion about commercial design parameters...

And whether or not they were based on formulas... or guess work...

And for heavens sake... you basically agreed with me that it was based on trial and error... and tweaking...

I called it the common "suck it and see" approach.. you called it the "seat of your pants" approach...

I didn't even specifically argue whether or not BioAqua's system constituted a "commercial system"...

Likewise I've addressed points recently regarding Nanniode system design... and other issues...

But read through that thread Journeyman... and you'll see that not only was I not the only one... but that in fact there were many others... expressing not only similar views... but a lot more unkindly than myself...

Likewise with BioAqua... or many others...


You seem to think that if I address anything you post that I do so on some sort of personal basis... I don't...

On the other hand... you appear to single me out for my posts.... even when others are posting the same thing... sometimes even more vehemently...

Nobody has to read.. or take notice of anything I write.... I offer my opinion and knowledge... just as any one else...

If I choose, or choose to not do so... now or in the future... it wont be to "rest on my laurels"...

Sorry Nanniode... and at the risk of beratement... but the statement is correct...

The fact that your system is supplementary fed by algae, phyto/zoo planktons.. and moringa etc...

Makes applying the "formulas" more difficult... as they relate to commercial pellet feeding... and are based a such upon optimal growth strategies for a species in RAS aquaculture...

But they can be applied to RAS aquaponic systems... as most commonly discussed.. and applied...

You have basically adopted a pond based natural feed strategy.. (with supplementation)...while stocking at RAS style densities... with a mix of external solids filtration...and utilising some limited plant production as a means of nitrate reduction.. and some level of filtration...

Aquaponics in a sense for sure.. but not a standard media bed design for which "the ratios" have, or can necessarily be applied...

In a commercial sense... I have grave doubts as to your approach.. even with Tilapia....

In terms of oxygen demand.. and optimal fish growth rates...

You have posted that your fish have grown from 1 inch to 2-1/2 inches in two months.. and hope to harvest in another 4 months...

I don't believe that you will reach the projected harvest in 6 months...

The accepted growth rate of healthy tilapia is 1.28inches per month.... from a fingerling (not hatched yourself)...

At 8 weeks they should be about 3.5 inches if stocked at 1 inch...

Normal commercial growth of Tilapia to 500 grams is about 10 months......

To get to market of say 500 grams at your current growth rate....it will take at least 20 months from 1inch....

That's not an acceptable growth rate for a "commercial" operation... and no where near what a pure pond based... or even a properly designed RAS could achieve...

To be blunt.. I'm not convinced that.. without substantial modification... you fish will survive pst another two months... and only that long due to the fact that your temperatures are cooling...