# Self-sustainable Fish Tank



## Silang (Mar 28, 2017)

Anyone here successful in setting up a sustainable aquarium? Care to share your experience?

I am thinking of doing this for my next project. First establish a breeding colony of shrimps and pond snails. Will make sure to do my setup in a way to encourage algae growth, and make sure shrimps will have lots of places to hide and breed - that are inaccessible to fish. Introduce fish - 2 predators, 2 snail eater, and a small group of schooling fish. Aim is to have a self-sustaining plants, fish, snails, and shrimp population.

Stocking plan: couple dozens of shrimps (breeding population), maybe a pair of dwarf cichlids or badis badis, dwarf loach for snail control, and a few (3-4) small hardy fish that will survive on algae and other plant matter. Key is to keep the numbers low for minimal food requirement, and for easier maintenance and sustainability.

Also thinking of introducing scuds to give the predators some food variety, but not sure of how effective or destructive they are considering my setup plans.


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## Bananableps (Nov 6, 2013)

This is going to sound harsh. Your idea is exciting, and I don't want to discourage experimentation, but I don't think it's possible. To be clear, I _do_ want to discourage experimentation when it puts the welfare of animals at risk.

What exactly do you mean by "self-sustainable"? Do you just mean in terms of filtration needs, or do you mean a closed loops system that does not need food added to it? For the size food chain you propose, to not add any food at all you would almost certainly require something pond-sized.

If you are planning on making a no-food-input tank, with a food chain of algae<shrimp/snails<small fish<predator fish, you will not succeed. The fish and shrimp that you are thinking can live for a long time on algae need, at some point, a source of protein. In the wild, this would typically be small copepods, but even very large aquariums will be stripped of copepod colonies with a couple of fish in them. The higher predators that eat smaller fish will, if fed nothing else, eliminate the small fish population in an aquarium.

In a fairly large tank, I think you could pull this off with dwarf shrimp, but I would still be worried about malnutrition. Perhaps you could throw a small dead fish in every once in awhile to simulate a scavenger ecosystem. Even Opae ula shrimp can't live on algae forever - those "self sustaining" kits you see for sale are just mini starvation chambers.


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## Silang (Mar 28, 2017)

Bananableps said:


> This is going to sound harsh. Your idea is exciting, and I don't want to discourage experimentation, but I don't think it's possible. To be clear, I _do_ want to discourage experimentation when it puts the welfare of animals at risk.
> 
> What exactly do you mean by "self-sustainable"? Do you just mean in terms of filtration needs, or do you mean a closed loops system that does not need food added to it? For the size food chain you propose, to not add any food at all you would almost certainly require something pond-sized.
> 
> ...


Thanks for the input. No worries, this is still just an idea, and wanting to know if anyone here has done something similar. I meant is self-sustainability when it comes to food. You reckon it be more possible with just algae<shrimp,snail<small fish (that can also depend on algae) ? Having a 'top predator' really is tricky, especially in such a confined space. 

I read a blog a couple of weeks back about a planted tank by a window, with just shrimps and a couple of scarlet badis and the blogger claims it ran on its own for more than a year until his plants overgrowed and engulfed the entire tank, disrupting the balance. Trying to look for it again...


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## Axelrodi202 (Jul 29, 2008)

Just schooling fish would be enough of a predator load on shrimp. 

Scuds would be a bad idea. They outcompete shrimp (especially babies) for food, leading to the shrimp colony's decline. Plus they eat certain plants like mosses.

I think at the very least you will need to change water. No feeding could potentially work in a very large tank with very few animals.


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## KayakJimW (Aug 12, 2016)

I'd think about a refugium/ sump designed to propagate copepods, etc in a way that the fish can't wipe them out entirely. No prefilter on return pump so copepods would get sent to main tank little by little, as the colony maintains itself below.


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## PlantedRich (Jul 21, 2010)

I might guess this would work only for a very short time as it doesn't really work long term in nature. We tend to think of long term as being a few years, while nature does it in decades or longer. What we think of in nature as self sustaining is often something which nature disrupts otr totally changes every so often. It's just that nature thinks in different terms. We think if a lake has been there for 50-100 years it has always been there. But nature often sends in something like a flood, drought, fires or landslides to rework the situation. 
While we think of things as being bad to kill a group of fish, nature often does it quite routinely. Notice how little nature cares if the human population in Puerto Rico is wiped out and replaced with something else? 
When things are not balanced that well in nature, I don't expect to ever do it myself.


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## Bananableps (Nov 6, 2013)

Silang said:


> Thanks for the input. No worries, this is still just an idea, and wanting to know if anyone here has done something similar. I meant is self-sustainability when it comes to food. You reckon it be more possible with just algae<shrimp,snail<small fish (that can also depend on algae) ? Having a 'top predator' really is tricky, especially in such a confined space.
> 
> I read a blog a couple of weeks back about a planted tank by a window, with just shrimps and a couple of scarlet badis and the blogger claims it ran on its own for more than a year until his plants overgrowed and engulfed the entire tank, disrupting the balance. Trying to look for it again...


That sounds interesting. I'd like to see that article. It is worth bearing in mind, though, that a year is not a very long time to the metabolism of a cold blooded animal, particularly invertebrates. The creatures we keep in our aquariums can live for extended periods of time without eating anything at all, and they can live even longer on food sources (for example, just algae) that are ultimately deficient in necessary nutrients in the long run. Shrimp can even breed while starving, essentially burning body mass away to create offspring until they whither away. So again I'm interested in reading this article, but I think we should take an experiment on that time scale with a grain of salt.

I should concede that I am not 100% positive that neocaridina are unable to survive on algae alone. There are certainly many organisms that can. Even then, though, I'd worry about edible algaes getting depleted and non-edible algaes taking their place. 

There still might be some version of this that is possible, I just want to emphasis caution because there is a significant risk that you could end up building a very elaborate starvation chamber.

How many gallons do you have to work with by the way?


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## Silang (Mar 28, 2017)

@Bananableps can't find the article anymore. 

I don't have concrete plans now, what I have is a 4 feet space in my bedroom. And so I am playing with different ideas what to do with it, this 'selfsustaining' or maybe more appropriate as "semi sulfsustaining tank" as one of them.


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## AbbeysDad (Apr 13, 2016)

I think perhaps the closest thing to a self sustaining tank would be with the Walstad method (or Walstad inspired) that uses a sand capped soil substrate, natural light, a heavy plant load with a light bio-load, fertilized only with fish food and no (or infrequent) partial water changes.

Setting aside the gloom and doom of natural disasters, I think some tanks are (or could be) more natural than others...but would still only be 'almost natural'. The keys are lots of plants, a light bio-load, and very modest fertilization. 

However, like routine rains, I feel that periodic partial water changes are necessary to maintain a high level of water purity that results in the best environment for inhabitants (as I don't think anyone has ever recommended starting a new tank with dirty water!)


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## PlantedRich (Jul 21, 2010)

When I think of this project, I look at the really big efforts made by some of the major groups. Like some along the coast that have a whole ocean full of fresh sea water to be pumped through and almost unlimited time and money plus staff. Or the Chicago aquarium for freshwater??
But even with the massive amount of knowledge and effort involved, it still takes a very large full time staff to keep it going. 
So it would be my guess that we might get somewhere in the right area but not really find the magic.


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## tropicalmackdaddy (Mar 7, 2012)

closest thing I have seen to a self sustaining aquarium was a guy's 5 gallon that he had very heavily planted, with cherries and 1 scarlet basis. He said the cherries lived off of the algae and microscopic stuff, while the scarlet badis hunted the baby shrimp. I think he still gave it live blood worms every 3-4 months or something like that though. I can't find the journal...


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