Pond for ducks and fish

I have a question of what would you think is the minimum size a pond would need to be to sustainably raise fish and ducks together in a natural way with little input.  Also what recommendations for types of fish and vegetation could be grown to sustain this ecosystem and provide for the feed and health of the pond.

How much input is little input? In my location it would have to be a very huge pond to survive our summer droughts without regularly adding more water. That's why we haven't planned one for our yard.

Casie Becker wrote:How much input is little input? In my location it would have to be a very huge pond to survive our summer droughts without regularly adding more water. That's why we haven't planned one for our yard.

I live on the east coast with lots of lakes around.  By inputs I know some smaller duck ponds require constant cleaning and some fish ponds require aerators, filters, nutrients, and other human inputs to be regulated in a controlled way.  I'm looking to replicate something more like nature.

I'd think a half acre would be about the minimum size for enough habitat for fish and ducks, but that's just a guess.  Both Geoff Lawton and Sepp Holzer seem to have smallish ponds on their farms.  Really tiny ponds can have trouble with temperature swings which can be hard on fish.  

Brandon Green wrote:I have a question of what would you think is the minimum size a pond would need to be to sustainably raise fish and ducks together in a natural way with little input.  Also what recommendations for types of fish and vegetation could be grown to sustain this ecosystem and provide for the feed and health of the pond.

Check the evaporation rates in your area to see how much you lose in the summer vs rainfall, etc...Deeper, less evaporation. If you dig will the pond hold water? Clay or sandy soil, etc...Some fish need no help at all such as tilapia, catfish. The floating duck house idea works well..

Tyler Ludens wrote:I'd think a half acre would be about the minimum size for enough habitat for fish and ducks, but that's just a guess.  Both Geoff Lawton and Sepp Holzer seem to have smallish ponds on their farms.  Really tiny ponds can have trouble with temperature swings which can be hard on fish.  

That's what the research I've read has said for stocked fish ponds.  I'm having trouble finding information for adding ducks into the mix.  Since they produce a lot of waste as well I wanted to know how many ducks or how much larger the pond would need to be.

Personally if I were making a pond, I would make it as large as I could afford and the topography would allow.  I can't see any drawback to a large pond except the greater expense of having the equipment out longer.  Go big!

Assuming you are in an environment where precipitation exceeds evaporation and an open pond is a reasonable thing to do, then you get into things like what are your temperature ranges, how many ducks/fish are you wanting to raise, what thoughts have you given to plants, etc.

Lawton, discussing fish ponds, says 1.5 to 2 meters deep is sufficient.  He is talking about ponds intended for producing substantial quantities of fish and recommends not building wider than can be readily netted - I think he said 24 meters across, but don't hold me to it  I don't know what sort of inputs he is considering with these designs.

The kinds of fish you choose will impact your pond design - trout need loads of oxygen, but catfish not so much.  Temperatures impact your fish choices, and if you're going for a natural pond, you will want to stick with native species since you are not controlling them and anything in your natural pond can escape into your local waterways.

The larger the load you put on the pond, the bigger the pond needs to be.  While you want to minimize your inputs, the pond requires inputs, so what are the parameters of the naturally available inputs on your site? What kind of sun exposure, precipitation? What potential does your site have for natural oxygenating waterflows, such as from a higher pond running down through flowforms to pick up oxygen and carry it into the lower pond, or from swales where the overflow spillways are set to feed the pond, again, running through flowforms to maximize oxygenation on the way into the pond.

Do you have trees overhanging the pond dropping fruit into the water to feed life in the pond? Insect populations, again, natural inputs of food for the fish and the ducks? Is your area warm enough for you to grow water chestnuts? They're a yield for you and for pond life, as well as habitat.

Oxygen levels are affected by turbulence, is your pond site in a windy location, or a still one? More wind means more turbulence and more oxygen. There are even some wind driven machines that could serve to agitate and oxygenate, if your pond has reliable wind.  For example, a vertical wind turbine driving an archimedes screw could lift water and drop it back into the pond, thereby adding oxygen.

Are we speaking of a self-sustaining system? One where the fish population maintains itself through natural breeding cycles?  How much do you want to be able to take out of the pond?  Same questions for the ducks, looking for a self-sustaining population? How much do you want to be able to harvest?  

Scaling the system is built on lots of parameters and a fair bit of guesswork  My gut instinct agrees with Tyler about building the largest I could manage, but I would still make every effort to analyze my site and design to take advantage of nature's inputs into the system  One time energy inputs that yield on going returns over the long term rather than on going inputs, sounds like permaculture.