Backyard Aquaponics
A place to discuss aquaponics

of course if you include the growbed factor that might compensate for the hr factor, Steve
but why should it?
I am trying to disconnect them because they are a bother and call for more equilibration.
why should you deny the hr factor as it is obviously present?
it can be compensated but not denied.
fresh, aerated water is the main element fish require for healthy and "happy" surroundings.
fresh water available to fish can only be calculated if you include the hr factor.
no way around that.
You don't need to "dump" nutrient rich water, as you can feed the "surplus" nutrients to either worms or plants or vegetables that are not incorporated in the AP system as is.
The setup I proposed with a settling tank and if needed an extra biofilter (don't forget I mentioned that too for the necessary conversion of nitrites to nitrates, though I imagine the already present growbeds will easily take care of that) allows for all of that.
With added flexibility where the partial or complete harvesting of fish or plants is concerned.
Win-win-win all the way through.
all at no considerable extra costs.
what could be against this?

greetings

Frank

when you say fresh areated water can only be calculated by including the hr you are not considering the nitrate factor of the water. no increase in water turn over will effect nitrate. it will only be lowered by exchange out of the system via dump OR via feeding non connected plants with it and replacing with fresh water OR via plant extraction WITHIN the system.

Worms will do nothing with an aqueous nutrient such as nitrate (or phosphate and potassium for that matter)

even if you ditch growbeds and use nft the nutrient reduction will soley be from plant uptake in an AP system.

look at the UVI system, massivly long floating rafts (no growbeds) but an increase in turnover per hour at a lower plant density would accomplish nothing.

please re-read this post at least twice with an open mind

I always reread the interesting posts twice and another time while replying
then I read my reply on average five times and rephrase to try and eliminate what could possibly be interpreted as stingy
then I preview my post and add some smilies here and there to smooth out even the last few creases
I even apply a psychological tactic to soothe the reader and put him in a good mood:
I first agree and only later hesitantly object
hope it all helps

the "open mind" has never been an issue. not with me.

to topic:
of course you are right concerning nitrates buildup.
too much of them might cause extra stress

While nitrates are not toxic to fish it still is advisable not to have a buildup.

but you seem to overlook the fact that the settling tank and it's connection to the worm bed will almost completely eliminate the solids OUT of the AP circuit, together with all the nitrites and nitrates and what have you they contain.
this is indeed a "dump", but an ecologically responsible one, completely in accordance with AP spirit:
nothing is going to waste

so there will be NO buildup of nitrates in the fish tank at all from these solids.

I seem to have read somewhere that this can go up to 40% of all nutrients (need some help here for confirmation, I can't find it back)

If that is the case, this simply means that you can either increase the fish population by 40% or reduce the growing area by 40% or any combination of these and still have a balanced system with even healthyer fish and greens.

Or you can balance your system after (partial) harvest of fish and/or vegetables.

Whether the worms consume the nitrates etc. and transform them into animal protein or not, I don't really know.
are you positively sure they don't?
the worm bed also contains nitrifying bacteria, but as said this is outside the AP circuit, so no nitrates are flowing back to the fish

maybe it isn't all that important: if they don't, these elements will enrich the worm tea and the compost produced by the worms.
both are interesting by-products.

In any case the hr factor should never be eliminated from the description of fish density if only for the O2 contents which will make your fish happier and healthier

I read that many AP-ers only run their pumps for very little time and often switch them off at night.
I believe that to be a mistake
no wonder they have to recur to air stones for aeration
here are some more arguments why a pump is preferable for the task: a pump will allow for fast, continuous solids removal out of the fish tank, limiting O2 needs in the fish tank, and does that in two ways: by pumping the solids out AND, with tangential inflow, by producing an eddy which will concentrate these solids in the center, AND the pump will ensure extra aeration.
An air stone will cause a lot of stirring and prohibit settling of the solids.

to come back to my conclusion:
adding a settling tank and a worm bin is an extra asset for any AP system: next to taking care of the solids, the worms will also compost leftover scraps from your vegetables and garden, your paper and cardboard, all to be transformed into valuable protein food for your fish, and into compost and worm tea
this will allow you to grow (maybe up to 40%) more, healthier fish in the same system
and is entirely compliant with AP spirit: nothing to waste.

greetings

frank

So you know this to be fact then frank, and so presumably you will be doing the
test yourself and can tell all of us the finer details when you have it done!
So with such minimal additions we can expect your finished AP system sometime next week.
What do you do with your worm tea, add it to your soil garden?
I don't have a soil garden as they are too much work!

I also don't think I am going to re-design the wheel so will leave my system
as the manufacturer intended it.

Your quote:An air stone will cause a lot of stirring and prohibit settling of the solids.

My airstones helps heavy particulates to settle but my pump (sump return) with venturi
stirs them up again then system pump distributes the solids to the GBs the GBs clean & airate & refreshes the returning water.

I see where your coming from Frank, but I dislike the the attitude expressed by you, upon ppl doing their thing.

If you had some practical experience in the BYAP I would be entirely more convinced.

Have a lovely day

PS Do you know anything about concreting, you may have some tips for me

I'm trying hard Frank (really)... but you're not entirely correct mate....

Not neccessarily wrong about removal of the solids "assisting" in the removal of nitrates...



True enough in its self... unless/until you were to "add" back the "settled" water.... or dump it

But you have overlooked a fundamental fact... applicable to aquaria, aquaculture and aquaponics....

The nitrification cycle.... and it's major component ammonia..... ammonia=>nitrites=>nitrates...

And yes, the conversion of solid wastes in an oxygenated RAS system will break them down into ammonia... and will eventually overload a water body, or breakdown into nitrous oxides by anaerobic processes....

That's why aquaria and RAS aquaculture systems often remove the solids... because they have no other way for the potential extra ammonia load to be processed....

And I bold the word "extra" for a deliberate reason Frank....

For every 1kg of feed... 0.25-0.5kg of solid waste is created (poo + uneaten feed)... BUT 0.03kg of ammonia is created (by respiration and excretion) and 0.25kg of carbon dioxide is produced.

Pond based aquaculture utilises algael blooms to convert free ammonia... aquaria and RAS systems filter the solids out, because they have no other way to deal with them....

Then they employ some means of bio-filtration, small in the case of aqauria - large for RAS....

To convert the toxic free ammonia waste... in solution.... via nitrification into nitrites and nitrates....

If it's not done... it rapidly builds up and becomes fatally toxic...

Removing the solids will deal with much of the "potential" ammonia.... but not all....

Yes (and noted) an addition of a bio-filter will, if sized correctly, deal with the remainder...

But nitrates will still accumulate and become cumulative... there are ways to deal with it...

But the beauty and simplicity of an aquaponics system is quite simply....

It does it all... ammonia conversion, nitrification, solids conversion, nitrate removal and oxygenation.....

With healthy mucho edible fish and plants to boot.... with minimal water usage...

What could be more simple in concept and design than that ????

FYI...



Hope this helps,

Greetings,
Rupe

All the comercial systems I have looked at with the exception of Monya's and Wilson's have focused on the fish and used the AP side as a filter for the fish. As far as I'm concerned the best atribute of ap systems are there exceptional plant production. If you want fish do aquaculture but ap systems are best at producing plants with a few aquatic cweetures as cream. As for a delicate balance the major advantage of the flood and drain GB ap systems is that they have the potential to be so stable. Many people don't even bother testing their water which is unheard of in full on aquariams, aquaculture and hydroponic systems. If these systems were so delicate then there is no way that people could get away with this.

Furthermore one of the major advantages of the F&D GB AP systems (hows that for acronyms) is that the solids are not removed. Therefore keeping all the nutrients within the system and available for the plants to utilise. It is this feature that allows these systems to produce so much fruit as compared to the leafy greens of the DWC systems where the solids are removed.



Harsh C1

Rupert,
I have heard about the nitrification cycle
thank you for the long but unnecessary explanation

I don't see where it comes in conflict with the idea of adding a worm bin to an AP system

in the sentence:

the most important words are "from these solids"

That is what I wanted to explain

according to your calculations 0.25 to 0.5 kg of solids could be removed by a settling tank per kg of food
So will all the ammonia these solids produce.

so we are left with 0.03 kg of ammonia and 0.25 kg of carbon dioxide.
Won't the plants take care of that?

After all, I have nowhere suggested to remove ALL the plants, I am still talking of an AP system, not a RAS.

The settling tank will allow you to decide whether you want to remove some of the solids if and when you wish to do so.

To reply to the others: this is just an idea, and I think it is a good one, that offers flexibility to an AP system along with other adavantages.
Nobody has to pick up any of my ideas (nor even has to read them), we live in a free world.

But I do hope you allow me to defend them, don't you?

Frank

ROFL I'm not going to touch that.


How did you know I only read the first couple of paragraphs.

Postulate, discuss and defend Frank... no problems here....

Did note your point about "NO buildup of nitrates in the fish tank at all from these solids"...

And yep, plants can/will take care of the rest if the solids are removed...

But in a simple, even small scale AP system... they will anyway...

As they will any, or most of the nitrates... it's just a matter of scaling the growbed/plant capaity to match the feed rate/stocking density.

I agree with you Frank, that higher densities can be acheived by removing solids... in fact it's essentail beyond any densities above 6-10kg/m3 IMO... about the extent of a normal backyard system...

Anything higher IMHO... involves sophisticated, often expensive, high maintenance filtration equipment... usually involves some degree of water dumping...

And IMHO... requires additional supplementary aeration.

My aquaculture notes from the recent Recirculation Tank Technologies course specifically maintain that up to 40kg/m3 can utilise aeration by normal air supply...

But anything beyond that requires pure O2 injection, high flow and low turbulence....

Primarily because, normal air only contains (at best) 21% oxygen (O2)... the remainder being Nitrogen (N2)... potentially adding to the nitrogen/ammonia load in a system...

And that it's just not possible to saturate a body of water to the level of those stocking densities with normal air...

Not saying your ideas are invalid Frank... perhaps voicing doubts as to their practicality for most people who may prefer a system that is basically "low/no" maintainence.... simple... KISS

Would really like to see you build a system based on your ideas Frank.. seriously... so that we can see the physical implementation of your theories... the costs, and maintenance involved...

Mate.. you might substantially change the way that people approach AP... go for it...

Thanks Rupert for opening your horizon (sincerely)
I am building my system and will post some pictures whenever I think I am ready for it (it may take a while)

To all others: To my opinion all is said on this subject and on the one on airlift pumps and air stones
So I will not bother those who are annoyed by my "banging the drums" any more

I will probably summarize it someday and post it in the files section for referral for whomever might be interested

but for now construction has priority

greets

Frank

Hi Rup were did you do you recir course?
and have you heard of Dr Brett Roe?

Natfish Piggy... Trenayr campus, Grafton... was run by Glen Searle.

Yep have heard of the good doctor... although not recently....

Cool Glen is a great Guy. Dr Brett Roe got the first phd in aquaponics in Australia
(not Leanard Wilson) and has a company called vermiponics you should check it out.

Ah yes Vermiponics... actually first bumped into Brett Roe surfing Nth Stradbroke....

Believe he's been doing some work with Geoff Wilson along the "green roof" lines...

Just an aside.... neither Wilson Lennard or Brett Roe have PHDs in aquaponics... there's no such degree course offered in any Australian university....

Both have written dissertations/thesis that have incorporated some aspects of aquaponic integration.... as part of there respective degrees...

Dr. Brett Roe Ph.D. Applied Science. CQ University

Dissertation: Ecologically Engineered Primary Production in Queensland Australia - Integration of Fish and Crayfish Culture, Constructed Wetlands, Floral Hydroponics, and Industrial Wastewater.

Dr. Wilson Lennard (BSc. Hons.) RMIT's Department of Biotechnology and Environmental Biology

Both are very worthy people undertaking great research....just being picky....

Geepers people, some interesting and very useful comments from all concerned on this one. I was searching for an answer to my water quality and stumble on all of this.
My 79 Atlantic Salmon (incl the Kamikaze that leapt out the tank last week and was found very dead like on the concrete) are still doing really well.
However, I have began to notice a fair amount of solids and food waste on the bottom of the tank and a small layer of oil residue floating on the surface ( I assume from the rotting fish pellets). Water clarity still clear as.
I have so far: Backed off feeding and cranked up the air stones to stir up the bottom whilst running the pump for several hours at a time . Also topped up water levels as required.
Ammonia and nitrite levels still at 0.0ppm and nitrates finally began to rise to 5ppm. So all good there. But, salmon are real skittery and I don't reckon feeding properly. They seem 'on edge'.
But my 9000l pump is 15min on / 45min off for 4000lt of water so nowhere near enough to cycle / turn over the water efficiently to pump solids regularly.
Apart from removing solids by hand, does anyone have any other suggestions to what I am doing and is this about 'normal' modus operandi for everyone else? Or should I just increase the time the pump is on and maybe every 1/4 day have it run for 1 - 2 hours then back to the 15/45 cycle?
This is all going to be even more pertinent as the fish continue to grow.
Cheers
T