aquaponics effect on sealed room co2 levels?

bajangreen · Mar 10, 2014

In Aquaponics we use manure from live fish to grow plants, I am wondering if i could calculate how much fish would be need to provide a 4*4 canopy with all the co2 it needs .

Would be interesting if this can work.

Only Ornamental · Mar 10, 2014

It could I guess... the main limitation I see is the welfare of the fish. Especially the high nitrate levels needed for the plants may pose a real health threat for most fish (for that reason, fertilisers for aquaria usually no nitrogen and not only because manure and food remnants provide enough).
You'd need to choose the fish species very carefully to match the aquapontics conditions provided. The temperature is rather too low for most 'ornamental' (tropical) fish but too high for cold water species; the high nutrient level speaking for brackwater species doesn't match with the pH, water hardness and current; you'd need also a species which neither depends on soil nor free surface; an obligatory carnivorous species may be advantageous; and so on... Maybe the three-spined stickleback could fit the bill, they are very hardy and accept many suboptimal culture conditions.
But still, it may be easier to keep the fish and the plants separate.

BTW I don't know how you want to find out how much CO2 the chosen fish species produces or the other way round who many fish you need for a given CO2 concentration. Besides, many aquaria have a CO2 supplementation because the plants in the aquarium use more than any fish population could supply.

bajangreen · Mar 11, 2014

Well Aquaponics is pretty well researched and i am sure someone is growing MJ in an Aquaponics system somewhere. Most people use talapia fish as the nutrient source and it works well for most vegetables.

In Aquaponics because the plants are continually taking out nitrates it never builds up in the water. This also means that you can stock fish at very high dencities. 1.5 pound per 5 gallons. So my plan is to have 6 bukets with plants and 3 bukets with fish for a total of 15 galls fish tank allowing me to have 3.5>4 pounds of fish.

Is there a way to find out how much co2 4 pounds of fish will produce?

Only Ornamental · Mar 11, 2014

bajangreen said:
Well Aquaponics is pretty well researched and i am sure someone is growing MJ in an Aquaponics system somewhere. Most people use talapia fish as the nutrient source and it works well for most vegetables.

In Aquaponics because the plants are continually taking out nitrates it never builds up in the water. This also means that you can stock fish at very high dencities. 1.5 pound per 5 gallons. So my plan is to have 6 bukets with plants and 3 bukets with fish for a total of 15 galls fish tank allowing me to have 3.5>4 pounds of fish.

Is there a way to find out how much co2 4 pounds of fish will produce?

Talapia sounds good, pretty much conformable with the factors I summarised. :yes:

I'm no expert in aquapontics; the two versions I know are 'normal pond plus fish together' for rice, taro and alike and a separate fish pond and no matter what plant irrigation with the ponds 'waste' water behind. Don't know what you want to make...
Separate/serial has the big advantage that you can mix additional stuff into the water without bothering the fish.
The former is a version where a good amount of the waste (fish poo) falls to the ground and forms an organically dynamic mud layer full of slugs, worms, micro-organisms etc. and a good amount of the nitrogen is liberated there and directly taken up by the roots. Also, it is often combined with ducks

.
The second version (AFAIK) uses constantly flowing water with the fish on the 'fresh' side. Obviously, the amount of water used is high and only pays off where you have a natural fresh water supply like a river but it doesn't work with tap water.

I suppose you're going to use no soil in the fish tank and are going to recycle the water in an eternal circuit fish->plant->fish etc., right? I judge from my experience with aquaria (don't know for sure cause I'm better with aquaria than with cannabis LoL) that this setup is doomed...

What troubles me is the amount of fish per volume; poor fellas *sniff*! In a big pond it matters less because they can swim wide distances but in a small tank... a half pounder in a 5 gallon bucket, if that ain't cruelty to animals! :no:

At least use one big tank for the fish and not three small separate ones!!

Concerning the CO2 output: You could estimate that maybe half of the carbon from the food is converted into CO2.

1TWISTEDTRUCKER · Mar 11, 2014

if I am understanding this,,, You are trying to calculate the Co2 production of the fish so You can use the Co2 as a benefit to Your plants, Correct?

I think it would be negligible, especially in such a small system.
In all the research I have done on aquaponics, I have not come across any one that even mentions the concept.
I did find one person on youtube that was growing Mj in an aquaponic garden.
He used a Rubbermaid stock tank for a res/fish tank with an EnF table on top for the plants.

Back to the Co2 thing, I think You'll get far more Co2 using a getto DIY yeast method.
And basic feeder goldfish will work fine in Your system, They love watter temps in the low to mid 60's. about 10 feeders to a bucket.

Peace; 1TT

Only Ornamental · Mar 11, 2014

1TWISTEDTRUCKER said:
if I am understanding this,,, You are trying to calculate the Co2 production of the fish so You can use the Co2 as a benefit to Your plants, Correct?

I think it would be negligible, especially in such a small system.
In all the research I have done on aquaponics, I have not come across any one that even mentions the concept.
I did find one person on youtube that was growing Mj in an aquaponic garden.
He used a Rubbermaid stock tank for a res/fish tank with an EnF table on top for the plants.

Back to the Co2 thing, I think You'll get far more Co2 using a getto DIY yeast method.
And basic feeder goldfish will work fine in Your system, They love watter temps in the low to mid 60's. about 10 feeders to a bucket.

Peace; 1TT

He wants to use it in a sealed system. I guess nobody does that and that's why there's no info about it

.
And you're absolutely right about the yeast working better (more efficient nutrient conversion, way easier to maintain, less space etc. blabla).
I first thought he's gonna combine fish and plants and that's why I didn't propose goldfish (they literally eat everything). Also, there might be a problem with size as they can grow really tall... but they also taste delicious

.

Granger2 · Mar 11, 2014

This sounds like a factory farm. 1.5 lb of fish in a 5 gal bucket? Shit. -granger

bajangreen · Mar 12, 2014

You are correct, I am trying to calculate the Co2 production of the fish so i can use the Co2 as a benefit to my plants,

I will eventually use one fish tank, as it works out better that way. I know it sounds like a factory type farm with 1.5 to 5 gal, but that is pretty much industry standard, the fish trive once the plants are keeping the water clean and you provide aeration. it could be guppies also, the actual setup does not matter much to me at this point. I am only concerned with the math.

If the maths shows that it could be done I will try for sure, I never heard anyone speak about this either, but the fish provide enough nutrients for the plants so why not enough co2 for them as well.

As for this "Concerning the CO2 output: You could estimate that maybe half of the carbon from the food is converted into CO2."

This type of thinking is what i am looking for, I guess the amount of carbon will be tied to the amount of food, but why half? Can you tell my why half and not a all or a quarter? Is there a biological equation for this?

Industry standerd for Aquaponics is 40g fish feed per m2 of canopy, thats for 32% protine feed. It does change according to different crops and mj needs some foilar feeding when in full flowering mode when in AP.

My next question is how much carbon is in 40g fish feed?

bajangreen · Mar 13, 2014

So I don't know how to work out that amount of carbon in the dayly amount of 40g of fish feed required for growing the m2 of MJ in a sealed room, I will guess its about 10g so is 5g of carbon dayly enough to be a benifit to my plants?

Co2 is measured in ppm right, so how do i convert 5g of carbon into ppm?
And how does this match up to the current standerd of co2 suplimentation?

Only Ornamental · Mar 13, 2014

Hi there,
Why only 50% of the food? Fish digestion isn't the most efficient one and not all food is transformed into carbon dioxide (a part is also needed for growth and lost with urine). So I figured that 50% would be a nice start.
To simplify things, take only the carbohydrates and lipids (fat/oil) into account and neglect proteins. What you need to do is figure out how many percent the carbons in those make up and then convert it to CO2.
The approximate molecular formula of a carbohydrate is (C6H10O5)x. The result after metabolism using 6 O2 and x-1 water is x times 6 CO2 and 6 H2O.
That means roughly 44 weight-% of carbohydrates are carbons or resulting in about 70 weight-% CO2 compared to the carbohydrates in the food.
Do the same maths for lipids by approximating the formula to C16H32. That gives ~85% carbons and 310% CO2.
Add both and divide by 2.
All you need to know now is how much CO2 you use to maintain a constant 800-2000 ppm in your grow room (which obviously depends on amount plant matter, growth speed and how hermetically sealed the room is).

Only Ornamental · Mar 13, 2014

Darn, just had a peek at my fish food and they contain roughly 45-50% proteins, 5-10% fat but carbohydrates aren't listed, just ~2% fibres.
Sorry, you gotta re-calculate the stuff ;( .
Forget about the carbohydrates, neglect the fat and use 50% proteins. But that gives a nasty formula... or rather I have not too much of a clue what to take and which part rally results in carbon dioxide. Maybe for a really rough approximation: Trash the amino part and round it maybe to C5H8O3. Reacting it with 5.5 O2 results in 5 CO2 and 4 H2O. That would give you 190 weight-% in carbon dioxide or 95% with the 50% conversion efficacy included.
That means, roughly the same amount of food given is freed as carbon dioxide.

guineapig · Mar 13, 2014

I remember Breeder Steve was researching aquaponics, and had a large amount of data.

As far as CO2 production by the fish, I think the vast majority of your CO2 would be from
atmospheric sources, not the water itself. You would probably need to supplement the
water with oxygen, at least with an aquarium bubbler.

I think aquaponics is only for the production of nitrates (fish guano) and other essential
nutrients that are absorbed by the roots of the plants.

As far as calculations for carbon and CO2, it is almost impossible to do this without
knowing every detail of your specific system.

:ying:

kind regards from guineapig :ying:

Only Ornamental · Mar 13, 2014

guineapig said:
You would probably need to supplement the water with oxygen, at least with an aquarium bubbler.

I think aquaponics is only for the production of nitrates (fish guano) and other essential
nutrients that are absorbed by the roots of the plants.

As far as calculations for carbon and CO2, it is almost impossible to do this without
knowing every detail of your specific system.

I agree with the oxygen and the fish guano; indeed I fear for the well-being of the fish in such a closed atmosphere.
Also, you're right concerning an adequate calculation of CO2 using only food as variable. It truly is impossible; but you can still approximate

. Assuming that a good part of the food ends up as guano, a functioning micro-flora would be good so that microbes could break down the poo and untouched food to plant available nutrients and, again, CO2. In the end, a proper CO2 measurement is mandatory; the plants AND the fish have both to be dialled in together to make it work properly.

BTW, guppies would be a good choice because it isn't an art to keep them alive but one not to do so LoL. How I hate guppy... my last ones ended in a frying pan, delicious

.

bajangreen · Mar 14, 2014

I took this from here
http://pubs.ext.vt.edu/420/420-256/420-256.html

Prepared or artificial diets may be either complete or supplemental. Complete diets supply all the ingredients (protein, carbohydrates, fats, vitamins, and minerals) necessary for the optimal growth and health of the fish. Most fish farmers use complete diets, those containing all the required protein (18-50%), lipid (10-25%), carbohydrate (15-20%), ash (< 8.5%), phosphorus (< 1.5%), water (< 10%), and trace amounts of vitamins, and minerals. When fish are reared in high density indoor systems or confined in cages and cannot forage freely on natural feeds, they must be provided a complete diet.

Obviously you know your shit Only Ornamental, I trying to picture a fried guppy with out laughing, I can't they are so small. Lol

Lets put some parameters to the room, and assume the room is 100% sealed and it has 1 meter squared of plants growing at its peak consumtion. The size of the room should not matter as it is sealed.
And we are feeding 40g of fish feed every 24 hours.

This amount of fish feed has been proven to provide enough nutrients for 1m2 in an Aquaponics system. I know mother nature has lots of tricks and surprises.

So your saying that for Every 40g of feed that go in 40g of co2 is produced?

bajangreen · Mar 14, 2014

I have a very basic understanding of what's going on here. Will this help any

Taken from here
https://www.icmag.com/ic/showthread.php?t=141160

Life is base upon chemical reactions; many, many chemical reactions; but the chains of chemical reactions known as photosynthesis are the basis in one way or another of all life. Photosynthesis involves the input of carbon dioxide and water with radiant energy and the presence of a catalyst called chlorophyll. The outputs are carbohydrates and oxygen. The formal statement of the process is: 6CO2 + 6H2O + ν → C6H12O6 + 6O2

?????

Only Ornamental · Mar 14, 2014

I suppose the carbohydrates just aren't listed on my fish food...
Anyway, it wouldn't change that much and we're still talking hypothetically

.
Yes, 40 g; although it sounds like a lot.

Just to give you an idea:
The rule of thumbs for aquaria, based on animal friendliness and clean water, is about a centimetre fish per litre water. Currently, I only have a 20 litre 'nano-aquarium' with about 20 cm fish and half again as much in shrimp and snails. They eat roughly 1/3 gram dry food per day (the N° of snails are adapting to food excess but I still get quite a bit of dirt).
Notably, larger aquaria gain in volume (3 dimensions) and the cm length are just 1 dimension but the fish in such an aquarium are generally bigger in again 3 dimensions. That said, pimping my aquarium to 40 gram food would result in a 2.4 metre fish chain

; I could also add just 4 big ones of each maybe 30 cm (the length of the aquarium) resulting in the same weight but not the same length. Or look at it the other way round, a 200 l aquarium with 2 m fish would eat more than 3 grams but less than 30 (bigger animals need less energy compared to body size messing up the quadratic calculations).
Back to the 2.4 m fish in my 'jar': Keeping the water clean and disease free would become impossible even with a constant supply of fresh water. Also, the waste (poo, mulch) will pose a threat and would have to be removed constantly. You need to figure out how, because you want to use that as nutrient without clogging plant roots, substrate, filter etc.
The exponential nature of these calculations explain why it gets easier and easier with increasing aquarium/pond size. For a really full aquarium like yours I personally would (well, I wouldn't but hypothetically...) go with nothing less than 200 litres; eventually 2'000 upwards with a constant water supply renewing maybe 5-10% per day. Think big, it really gets a lot easier!

Only Ornamental · Mar 14, 2014

bajangreen said:
Life is base upon chemical reactions; many, many chemical reactions; but the chains of chemical reactions known as photosynthesis are the basis in one way or another of all life. Photosynthesis involves the input of carbon dioxide and water with radiant energy and the presence of a catalyst called chlorophyll. The outputs are carbohydrates and oxygen. The formal statement of the process is: 6CO2 + 6H2O + ν → C6H12O6 + 6O2

That's correct.
This is the usual way of carbon fixation. The sugars are then used to make all the other nice things and serves to provide energy (the electromagnetic energy of sun light becomes chemical energy used to make for example 'physical' energy like movement and force of my fingers when typing this post). During all this, the process (above formula) is basically inverted and oxygen and sugar 'burn up' to carbon dioxide and water once again. The same happens when literally burning sugar (or wood) resulting this time also in heat (and a bit light).
This process is not perfect, some of the sugar is used to produce matter, to construct things, to grow, and another part is wasted cause it can't be completely burnt (for example urine contains still a bit of carbon). That's where my proposed 50% output come from.

bajangreen · Mar 15, 2014

Thanks for the responce only, I will look into this some more and if I do anything I will be sure to let you know, right now I trying to figure out if it is doable! What do you think?

HyDroid · Mar 15, 2014

I think this is an awesome idea.

I also think that the fastest way to really know is to buy a CO2 meter and put some fish in a sealed bucket with an airlock of the kind used in brewing mounted through the lid.

you could use an upside down graduated cylinder around the airlock orifice to estimate the (volume CO2 / second) = R averaged over a minute or an hour.

The CO2 should leave the system as gas, just like in brewing, after the solution reaches 3.7 ph, which isn't real great for the fish, so don't do it for too long. But they will be fine if they are robust and it's only a day.

After that it should be a simple matter to figure out the ppm you need.

Since the number of molecules of gas at a particular temperature, pressure, and volume is the same regardless of the gas (PV=nRT), let K = (the volume R of CO2 per second / volume of airspace in grow) = (number of molecules of CO2 per second / number of gas molecules in grow). Then K*10e6 is the ppm CO2 you can raise per second. This will let you know how fast you can bring a room up to snuff. You could use information such as CO2 flood cycle timing from the CO2 forums after that to figure out if it will work.

Alternatively you can consider the mass of carbon you wish to fix per second, use PV=nRT along with R (the rate above) to get number of mols CO2 / second which can yield grams CO2 / second.

You can run this experiment for $5 homemade airlock + $5 bucket + $5 graduated cylinder + fish.

The airlock could just be some hose from the lid of the bucket to a bowl filled with water with an upside down transparent measuring cup submerged, purged of air, with the hose situated so that any bubbles will be caught by the upside down cup and the total volume of gas observed. If everything is sealed well this will give an accurate reading.

If you do I will run the numbers on this thread.

Only Ornamental · Mar 15, 2014

Unfortunately this doesn't work like with beer because we're talking aerobic respiration and not fermentation.
It means that in the current case approximately one oxygen is used for one carbon dioxide produced resulting in no volume change.
Also, buffering the water below 3.7 wouldn't work with most fish and should be avoided because in the real case pH would be between 6 and 8 trapping some CO2 as carbonate.

But it was a nice idea showing that the Avogadro constant from physics class may indeed have an application in real life

.

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