[Thought Experiment] Self-sustaing aquarium/terrarium

[FishInferno]

I have been wondering about a concept that I have heard about but seen limited success on: Creating a self-sustaining ecosystem within a closed environment. This would probably be an aquarium, and here is my idea: (some prior knowledge of an aquarium helps here)

-really big tank, at least 100 gallons

-heavily planted, plants soak up nutrients from animal waste

-Small shrimp eat plant matter, reproduce quickly in large numbers

-Small-ish fish to eat some of the juvenile shrimp

-Fish would probably be an egg-scatterer, like Zebra Danios or Celestial Pearl Danios, so that the population does not boom, but enough babies survive to sustain a population of predators

-Only equipment in the tank: A heater, a light, and probably a pump to mimic natural water flow.

In theory, this should work, but there are probably several unforeseen problems. The end goal is to create a complete ecosystem including death and decay, with new organisms being born to replace the old.

Note: I am not actually trying to build this

[AngelLestat]

more big your tank is, more easy is to self-sustain..

But at that scale you are talking about, you will need to change the water once a while no matter how well balanced it is..

The good notice is that you start with fresh water tank and not saltwater.

I have a pond of 2000 liters + 5000 liters tanks to storage rain water and use it to recirculate and other uses in my house.

It works so well that I just need to recirculate a 400 liters of water every 2 or 7 days (summer - winter)

Edited June 11, 2015 by AngelLestat

[MunGazer]

My tendency to speculate on an artificial ecosystem are heavily impeded by the sense that I seriously lack what I suppose would be a very high level of expertise in biology and perhaps several other areas of study to render a legit assessment.

But enough modesty and common sense. How about I pretend as though I have something to offer, and then get enraged when I'm subsequently contradicted? j/k.

I'm really bored. How's this:

The system is simply too small. There may be some cycles that persist for a while, but ultimately the volume of the system, especially without being directly connected to a larger system, would reach some kind of unrecoverable state. Disclaimer: that's my amateur guess/opinion

[Kerbart]

In theory, this should work, but there are probably several unforeseen problems. The end goal is to create a complete ecosystem including death and decay, with new organisms being born to replace the old.

A self-sustaining aquarium. All you need to do is plug it in and it'll run for 10-15 years without maintenance. It would make an awesome decoration in an office, and most office managers would happily pay good money for such a piece of fascinating, every changing, low maintenance decoration.

And yet no one sells them. This might be a subtle indicator of the difficulties one will encounter building such an aquarium.

[Agate]

They've been selling these since I was a kid:

http://www.abundantearth.com/store/ecosphere.html

[PB666]

I have been wondering about a concept that I have heard about but seen limited success on: Creating a self-sustaining ecosystem within a closed environment. This would probably be an aquarium, and here is my idea: (some prior knowledge of an aquarium helps here)

-really big tank, at least 100 gallons

-heavily planted, plants soak up nutrients from animal waste

-Small shrimp eat plant matter, reproduce quickly in large numbers

-Small-ish fish to eat some of the juvenile shrimp

-Fish would probably be an egg-scatterer, like Zebra Danios or Celestial Pearl Danios, so that the population does not boom, but enough babies survive to sustain a population of predators

-Only equipment in the tank: A heater, a light, and probably a pump to mimic natural water flow.

In theory, this should work, but there are probably several unforeseen problems. The end goal is to create a complete ecosystem including death and decay, with new organisms being born to replace the old.

Note: I am not actually trying to build this

If you're going to experiment with this salt-water is not the way to go. Lets face it beta-fish can live in a mud puddle left by a water-buffulo eating mosquito larvae and breathing air. They don't have near the problem saltwater do with ammonia (ammonia is not poisonous at acid pH like it is at basic pH).

Take a trash can, put it outside and fill it with 30 gallons of water and place one gravid mosquito fish in it. At the end of the summer you will come back and you will have half dozen fish along or one nasty fish parasite.

[AngelLestat]

Note: I am not actually trying to build this

I dint read this before...

But my answer stay the same..

In theory... you can imagine a perfect cycle, in practice at that size... is almost impossible. (I am talking long time >1 year)

[cptdavep]

I know it can and has been done with just plants. Not sure it's possible to achieve with livestock too. The Walstad Method for planted aquariums is pretty close though, requires minimal maintenance.

http://www.theaquariumwiki.com/Walstad_method

Edited June 13, 2015 by cptdavep

[AngelLestat]

In your link it said: "Do water changes as needed" [some soils often require frequent water changes the first two months to remove miscellaneous toxins]

So is not self sustaint.

There are not fish either, although not sure if is a topic requirement.