pond size for self sustaining...?

[CometKeith]

ok. now I know what my pond really is...... a fancy cow trough. Being a city folk I never even seen a cow trough before!

 

[addy1]

nah cometkeith nicer than a cow trough!

 

[CometKeith]

Thanks addy, I always thought of it as a fancy birdbath with fish to entertain the birds!

 

[fishin4cars]

LOL, be glad cows don't fly Keith!!!!:regular_waving_emot

 

[CometKeith]

yes, I am thankful of that everyday. it would mess up air traffic at the airports, that's for sure.... I think to build something self sustaining, you would need a fresh water source to make up for evaporation (streams, underground springs, run off from higher ground etc.) and there is no guaranty as to what wildlife you would end up with due to the fact there would be natural predators. Also you would have to copy mother nature and have a much larger body of water for the bio-load of the fish than what most us keep. I was on the golf course today. They had some nice ponds, but I don't know if they are self sustaining. I would guess they need some maintenance.

 

[Telkwa]

I'd say 3 foot is a good depth to shoot for. I'm 6' tall. At 3 foot depth I could still shovel out of the excavation and into the wheelbarrow. Any deeper and it would have to be a transfer - to a tarp on the ground, then clamber out and shovel into the wheelbarrow.

Of course, that's only a factor during construction.

Now that the pond is finished, 3 feet deep seems almost not deep enough. Watching the fish use the entire water column adds a sense of dimension and character to the pond that would be lost if it was less deep. I imagine at 2 foot depth the pond would seem more like watching TV. Flat and dimensionless.

 

[Ermasdaughter]

My pond is 90 cm around and 55 cm deep. I have loads of plants, 3 goldfish and a few snails and that's it. No filter or anything at this point. I just chose a sunny spot shaded by a banana tree and the water has been crystal clear and the fish ( I never feed them) growing fat since February.

I am going to add a solar powered oxygenator for the summer but so far so good.

The smaller pond of fairing equally as good too. No fish but loads of plants and algae eating snails.

It can be done!:lol:

 

[HARO]

Solar powered oxygenator??? We call that Hornwort! John

 

[sully]

As long as you have a lot of oxygen producing plants you shouldn't have to worry about keeping it shallow/wide to maximize surface area. The wider a pond however, the greater the volume; un-proportionately so. A 28'x28'x2' pond contains about twice as much water as a 20x20! That should be enough to dilute toxins etc. The jump in volume really picks up at 23 ft. I wouldn't recommend anything smaller for self sustainability. To tell you the truth, I don't know. I came here hoping someone could lend some eye witness accounts.

 

[mogsie]

there is so many variables that need to be taken into consideration first regarding this, you really cannot state a size and depth and expect that to work, you need to consider location and how much open sun it will recieve as this will effect evaporation rate and vegitation , soil type, depth of water table,climate, surrounding features and topography eg streams, hills/slopes, agricultural land, and surrounding vegitation, you will have to pay carefull consideration to the water contributories, where it comes from and how it gets there, wether by natural spring, stream or grond run-off, as this will effect a myriad of things from water quality,available oxygen, nutriants, and potential scource's of pollution, and rate of build up of silt, and then give as much consideration to egress of water, where is it going to go, how and by what means will it exit, as this may be controled by local laws and by-laws regarding waterways, (last thing you want is the environment agency on your back if you have polluted a waterway, i know people who has been fined £20000 over that) and all the answers to everything youve considered so far effects the bio-diversity of the pond, which is something else that requires consideration, what will it be stocked with, and what will occupy it naturally,not just fish and amphibians but also molluscs, birds, mammals etc, and can you find a balance between the two, undoubtedly in a natural pond where there is prey there is predators,
well i may not have answered your question but ive provided a few things for you to consider, and when youve considered them you will prob think of more things you need to consider, and if after all this considering !! you eventually get on built come and see me and ile give you some free baby fish !! lol

 

[sully]

I agree, a single variable is enough to ruin the whole magic pond size thing. I've seen small ponds sustain themselves, a few fish and the local wildlife, yet I'd imagine there are large ponds that have failed to achieve equilibrium.

There are however a few "magic" numbers. Ponds that are at least 2 feet deep tend not to overheat regardless of sun exposure, as mentioned by Adavisus, because the most of the light is absorbed by the time it reaches 3 ft. A 23 ft pond provides an increase in volume of around 40% over a 20 ft pond for a whopping 7000 gallons at around 2 ft in depth.

I'd like to know if anyone has seen a moderate sized, self sustaining pond. The smaller ones tend to be tea colored which probably has a little to do with all the twigs and leaves steeping in their small volume of water.