Duck Poo?

[Matt Trevatt]

Tilapia are typically gender selected, in that the growout stock are hopefully 95% ++ percent male. If this is not the case the fish start to breed and brood and this effects the grow out size. Its advisable to have caged predatory fish that can eat the fry to keep the fish from brooding.
I was experimenting with manure teas at one point. I had a large plastic drum filled with water that had a plastic basket of composted manure set into the top. Water was circulated to keep it all aerobic and I added some palm sugar to encourage the correct plant life to grow. Well my son just happed to have caught a tiliapia from one of the local ponds and I plopped it into th drum. For about a month I feed it spasmodically. A little later a catfish was added, never to be seen again I might add. Months later experiment over I drained the drum to find the Tilapia alive and in very good condition, very plump considering that I had barely feed it think it must have died. It was feeding off the algy from the manure. On manure\composting teas I think they have great promise to replace deficiency's in aquaponic systems. Nettle tea has everything you could want pretty much, shame that its a pest as well.

[Jeremy Trevatt]

My interest in this topic came about essentially because I have a dam on my property that is spring as well as catchment fed. I am going to be expanding the dam and actually looking at creating a couple of other connected dams on the property in close vicinity. The dam has a fair amount of sediment in it and I want to clean it up through natural filtration. Hence I am looking at incorporating a number of reed beds into the entire system.

Coupled with this is of course aquaponics. When my brother (Matthew Trevatt who posted in this discussion last) was over visiting from Bali I took him out to my land and we talked about incorporating the natural filters and duck poo into the aquaponics system. I have subsequently bought a bunch more books from Amazon on both Duck keeping and building natural ponds.

We want to encourage other natural life around the ponds (such as frogs etc), so am thinking we may need to have a safe haven for those little critters from the ducks. And it also would seem from Gary's comments that we may need to control the level of access the ducks have to the pond itself due to all the muck they introduce. Obviously the bio-filter side of things needs some thought. I wonder what critters clean up after ducks? So keeping a hand on the muck-throttle seems to be the key. We want to be able to produce enough nutrient to be useful for injecting into the aquaponics system.

We will talking to the excavator guy shortly and plan to have the new pond designs done over the next few months (got to allow enough time to read those books from Amazon). I imagine we will be looking at a couple of hundred square meters of pond surface area. The depth in some places in the current dam goes to 18 feet apparently... so there should be a lot of volume to play with.

In order to move water back up to the starting position we need to get some pumps going. I am wondering whether I should seriously consider a number of solar driven pumps... but am somewhat concerned about their ability to pump enough volume. I don't know enough about pumps at this stage to make an informed judgement. I would appreciate anyone's comments about that.

As anyone has read my other thread on 'CSA Experience and Advice' they will know that I am planning on putting up some 'semi-commercial' greenhouse operations. I still plan to do so, but am wanting to be a bit more inventive on the nutrient side of things. It is also pretty clear that at least in the short-term, pure hydroponics is much more commercially proven (I resist saying 'viable'). It is difficult for aquaponics operations to compete on a large scale with hydroponics operations. However from a localisation and sustainability perspective, aquaponics and more generally IBFP may well prove to be a smarter solution. Hydroponic nutrient and fish feed continue to become more and more expensive, so sustainable solutions are imperative.

I am not convinced that fish is a great long term solution on its own (don't shoot me down with your passion) to providing nutrient, simply because of the input dependencies and costs relating to those. As a basic example, if you cant successfully breed your own fish and provide for all their food requirements then aquaponics wouldn't be 'sustainable'. Therefore introducing other complementary elements is vital. I know that complete sustainability in a system is probably idealistic, but it is also a goal most of us seek.

I want to diversify the nutrient source. Part of my desire to do this is to really design something that is as sustainable as possible. It is clear that sustainability is most convincingly achieved through cooperating with nature, and nature has given us the remarkable example of balance between diversification and integration. I know that Gary is the man of experience in this area.

Comments welcome!

Jeremy

[GaryD]

Hi Jeremy,

Good to have you 'round again......where've you been?

Some of my past comments were premised on the notion that the duck ponds were small. If you limit the number of ducks.....and your duck pond is larger (several hundred square metres) then you'll have less of a duck poop issue. In fact, a few ducks in a large body of water will contribute the nutrients that will encourage other organisms like algae, aquatic plants, insects, frogs, etc.....

Have you considered using a traditional windmill to move your water back up to the header dam? While they only move the water when the wind is blowing, they will pump up hill to great heights.

I am not convinced that fish is a great long term solution on its own (don't shoot me down with your passion) to providing nutrient, simply because of the input dependencies and costs relating to those. As a basic example, if you cant successfully breed your own fish and provide for all their food requirements then aquaponics wouldn't be 'sustainable'. Therefore introducing other complementary elements is vital. I know that complete sustainability in a system is probably idealistic, but it is also a goal most of us seek.

I agree entirely......and the need for the full range of nutrients in useful quantities will encourage a much broader approach to the whole question of integration. Integrated backyard food production is almost entirely about converting the (waste) by-products of one process into the feedstock for another.

At the moment, aquaponics is seen by many people as an end (rather than a means to an end)......and that's fine for those who just want an interesting and productive hobby......but it's a stretch to suggest that AP is (of and by itself) sustainable.

The interest in worms and vermicomposting.....and BSF....and aquatic plants like duckweed and azolla.....is encouraging. Of even greater interest to me (in an IBFP context) is that one of the most frequently viewed threads in this forum is about Japanese Quail......nothing at all to with aquaponics but everything to do with IBFP.

Gary

[Jeremy Trevatt]

Hi Gary,

I have been moving the whole family to the country.. getting them settled in, finding my feet and still trying to earn a quid!

Poop is a wonderful thing isn't it? I guess its all a question of balance.. according to an article I just read 30 ducks per 1000m was the recommendation, so I guess on that basis 6 or so might be the go for my little operation. Nevertheless I will wait for my new books on rearing ducks to arrive before I jump to any conclusions.

What a great idea about the windmill! When we don't get any wind I will just have to rig up the bike machine to it and spend a few hours losing weight - an all round win!

I have been keeping an eye on the conversation around worms, bsf, duckweed etc. it all sounds good. I was also a great enthusiast for the quails... my wife thinks I'm a meanie, so I will have to 'do the deed' well away from the accusing eyes.

I have taken the approach of earlier advice you gave me which is to go slow. I am getting power on the land first, reading some books, then getting the excavator out to build enlarge the main dam and build the other ones. Then I guess once the dam and surrounding flora/fauna is in place I can look at procuring some ducks... I am guessing I will have to have some aquaponic grow beds ready to roll to pump the nutrient through... so that's a question of timing again.

In the mean time I am also considering setting up a basic greenhouse (net) system (maybe 400sqm) that can be ready to grow a summer crop in. I am thinking Basil may be the way to go. I know this does well hydroponically so it might be a good approach to try something on a slightly larger scale without a lot of risk. If the integrated poop nutrient is all sorted out, all well and good, if not I can always use hydroponic nutrient.

Jeremy

[GaryD]

Poop is a wonderful thing isn't it?

Yep.....it helps to make the world go round.

[Jeremy Trevatt]

Actually just need to make a slight correction. I used Google Earth to measure the proposed new pond sites and it turns out the total surface area is around 2500sqm. Not sure what the volume would be, however its probably fair to say that the greater the area the finer tuned control you can have over nutrient output, however it would also be true that the total pumping and filtration requirements will go up as well. I just need to work out an appropriate algorithm which will calculate the different control requirements.
The factors are:
- total volume of water
- water replacement requirements
- poop production (ducks, fish, crayfish etc) volume
- feed requirements
- grow-bed volume (strictly speaking I probably wont use grow-beds, but a NFT variation.
- nutrient control measures (such as duckweed)
- pump requirements
- additional filter requirements (particulate filter, reed bed filter, sand trench filters)

Anyone got a magic formula? I don't think the basic grow-bed/water-volume ratio is quite refined enough considering...

I was thinking that having separate duck-weed ponds could serve as a control mechanism to help manage nutrient output... each one could be used inline or bypassed depending on nutrient output requirements.

Jeremy

[Matt Trevatt]

Link with some intereting stats on Duck Poo and fish raising.
http://www.fao.org/docrep/field/003/ac526e/AC526E04.htm

[Matt Trevatt]

Same site but this time info on chickens

Fowler and Lock (1974) described the possibility of inclusion of poultry waste as a feed ingredient in catfish ration. Some farmers in Asia build poultry cages on a wooden platform above a fish pond, poultry feed together with spilled feed fall directly into the pond where it is consumed by the fish. This system is very practical, no cleaning of poultry cages is necessary, and poultry situated above the fish pond enjoy an excellent air circulation which has a significant cooling effect for laying birds which are particularly sensitive to heat stress. This system in terms of livestock waste management increases the profit derived from fish and totally eliminates the pollution problem. It is estimated that one laying hen will produce enough manure to generate about 6–8 kg/year of fish biomass. Manure derived from individual confined livestock species (annually) can support the following annual production range of fish biomass (Muller, 1980).

Manure from Fish biomass production (kg/year)
One dairy cow 100 – 200
One beef cattle 90 – 160
One sheep 10 – 17
One laying hen 6 – 8
One replacement bird 4 – 5
One broiler 3 – 4
One turkey 7 – 8

[organicusrex]

Please forgive me since I can't recall the source on my next interjection. I recall reading about an extravagant display in a shopping mall using tropical birds and fishes. The cost of feeding the fishes was pointless since people couldn't see them very well and the fish were removed from the display save one lonely trout. The droppings from the birds in the aviary was the only source of nutrition this trout received and it grew to large and healthy size before it was noticed by the maintenance workers.

I spent one summer working in a county park and the fish population had dropped significantly in one lake in the park. Fishing by the public was curtailed. We added manure to it once a week for 3 months during that summer and the following year it was opened up again for fishing to the public. We didn't have to restock the lake with fish.

Poo makes the world go around alright.

I plan to do some more research regarding the info brought forth by Jeremy and Matt. A portion of my property has a gentle natural slope, and since we all know poo rolls downhill, my AP design may get amended to utilize this profound principal of physics.

Thanks for the enlightenment.
Dean

[Matt Trevatt]

These stats are interesting - lotsa stuff on this page... is there a Oz native that is an algae feeder like the tilapia?


http://www.engormix.com/integrated_a...es_833_ACU.htm

Although there was no remarkable effect of the treatments on these water parameters; yet, it seams that fish ponds integrated with ducks (ponds No. 1 to 6) reflected warmer water with lower pH values and salinity levels but with higher DO contents comparable with ponds No. 7 and 8 (without ducks). Also, these changes were dependent on the ducks intensity, so were slightly stronger in ponds No. 1 and 2 (80 ducks / pond) than ponds No. 3 and 4 (40 ducks / pond), than ponds No. 5 and 6 (20 ducks/pond). These differences may be due to duck movements on the water surface, which help in enrichment of water with DO from the air. Moreover, the ducks excretion (with its uric acid) lowered the pH values. The movement of ducks on water surface improved the transfer of ambient temperature from and to water, so led to elevating the water temperature.