An Inquiry From The Press / Sealed Aquarium

[mjb]

Thanks for all the input!

PaulasPets, I don't think you're quite right that NASA has been researching these things for deep space travels. Most of the systems they have been working on are largely mechanical with a few biological components. They haven't built anything to house humans that was primarily biological, such as Biosphere 2.

However, your note was really fascinating to me in that you brought up an idea that has been occupying me more and more too: that the whole Earth doesn't "work".

It sounds like a joke -- obviously the Earth works, because we're still living, right? -- but it's actually quite a relevant idea. It's popularly proposed (for example on nature TV shows) that natural systems are supposed to be "in balance". However, there are many many episodes in the Earth's history where things have NOT been in balance, for example--

- the ancient change from a reducing atmosphere to an oxidizing one.
- the changes associated with ecological succession, for example how Mt. St. Helens will slowly change from ash landscape to subalpine forest.

... In fact the more you think about it, the more you realize that nothing in nature is ever in balance. it's always changing. It takes a lot of work to retain constancy -- such as a perfectly tended lawn.

If there's something cruel or unworkable about microcosms, I might venture it's that sealing plants and animals up basically forces them to find a balance, which turns out to be not so natural at all.

So that's the heavy philosophical part of what I'm thinking!

But I'm still interested in practical tips if anyone's created microcosms of their own. Or any other comments, on the forum or off.

Cheers,

Martin John Brown
http/martinjohnbrown.net
email: mjb2000ATgmailDOTcom

 

[Lateral Line]

Hmmm, we posted at the same time!

There certainly have been experiments for plant culture at least. The Arthur Clarke Mars Greenhouse project has been running since 2002 on Devon Island up in the Canadian Arctic. Might be worth your while researching that for a short while, I don't know how it would fit into your article.

 

[raptorrex]

Hi
What about
1 Ammonia( harmful to occupants))
2 Nitrite ( " " " )
3 nitrate ( " " " )
water changes?
disease?
how can you sort these infrequincies out if you cannot access the vessel
If we create an enviroment we must be responsible for its inhabitants.

Perhaps if you look in the setup in the beginners section and just read about cycling a new tank
you may understand how complex it is to create a good place for things to live in.
Beginners have enough trouble trying to create this enviroment with bad advice from some poor suppliers and killing fish shrimps etc with no fault of their own.
I dont think a sealed enviroment will work.
If i were a botanist i may be able to make this sealed enviroment work.
I guess mom.dad kids would see this in a store and purchase on a Saturday afternoon.
Its only my opinion and there are a lot of more experienced people on hear than me.
I stand to be corrected.
Ian

oops fingers too quick there.

even with open aquarium it is possible, if the tank is well planted, for the tank to be kept with no filter at all!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! it happens in nature too. in Cumbria, where i come from, we have little lakes called Tarns! theses are in fact just, big, dips in the ground that have filled up with rain water, and have no other water going in or out. many years a ago some of these had fish put in, the fish live very well and some are known for their good fishing. they are self sustaining microcosms too. the only water put in is rain and the only water going out is evaporating! they are essentially stagnant, but the life that gets a foot hold allow all other things to live well too. when i said many years ago, some are said to have been there for thousands of years!

so the answer to your questions is "well what about them"? lol quite apart from anything else, these sealed microcosm do exist and do work. Err however much you think they can't

take some advice from me, when someone asks a question like this, do a web search to get a little background before you post. it may avoid a VERY red face!!!

Does your tarn have a lid over it? would it not be replenished with rain water, evaporate in the summer freeze in the winter. These are all changes to the environment that nature has become accustomed too.
Why should i have a red face. Its my opinion.

I still stand by what i say.

ok lets start from the top if the system is started with cycled water, and has enough fish and plants to cycle oxygen and co2 it makes no matter that there is no filter. as said before Planted tanks with fish can live without any filter. sorry friend but that is fact. so that covers you questions about nitrates nitrites and ammonia!

disease is easy. Errrrrrrrrrr you quarenteen (i've found a word that does the FireFox spell checker nuts) the fish before you put them in ! they may die but they will not contract disease. as the environment is closed.

as for water changes providing the balance is right, and i don't pretend to know how to do it, in theory on water changes are needed.

lol i see your point about the Tarn, but even without a lid the environment below exists without help from the outside, no exit of toxins or waste, it is all taken care of by the ecosystem itself. yes it receives rain water, and it does evaporate, but because there in no egress of water or wast that will only increase the pollution, as it mealy concentrates the waste and toxins in the remaining water, requiring the system to develops ways of coping.

Bio Spheres are dysfunctional. but they do work. not my thoughts but fact. a large Bio sphere in the US stopped as i hear, not because it didn't work, but because it proved impossible to balance such a varied ecology, i beleave one of the main problems was the system was becoming overrun by ants . though this may not be correct as it was culled from a news bulletin many years ago.

finally your post, read properly the poster clearly id himself as press, he also stated he had these things already and that they work, however flawed they may be. his request was for any experience of these things, with a view to adding it to the knowledge he was gaining by keeping them not a lesson on how to cycle a tank! nor did he need to be told the thing he had in front of him could not exist. he did not say these things were to be sold!
but the posters point that in your thinking the Earth could not exist!!! is more than a little relevant don't you think. though i suppose the Aliens could be changing or water whenever they are seen. lol

 

[moeldner]

Are the Tarn's definitely closed systems (minus the lid of course)? Are you sure they are not exchanging water not just through precipitation and evaporation, but also though the water table that lies beneathe the ground?

If this is the case, it may mean that the "bad" things in the water as listed in other poss, are leeched out through the surrounding underground water, or at least the concentrations are kept in check because of these other potential avenues of escape.

My thoughts on the whole "closed ecology" is that it would take significant work to establish a balance in the system BEFORE it was closed - I don't think it would be possible to throw water, plants, inverts/fish in a tank, seal it and everyone's happy (even for a short period of time). there would be significant work required to establish that balance before it was sealed.

 

[andywg]

The final step, nitrate->Nitrogen is anærobic and not needed. The plants use nitrate as their nitrogen source for protein synthesis.

Just to say that one point repeatedly being missed here is that plants (and algae) prefer to take up nitrogen in the form of Ammonia than nitrate, therefore if they are the primary (or sole) mode of filtration there will be no cycle as the ammonia will be used up at source.

Because of this, if you plant heavily and stock lightly you can throw the fish in without any cycling.

One problem with such a closed system is that of overpopulation. If you have the right circumstances for the shrimp to breed, what population control will there be? Using the Earth as the cross example, there are numerous predators in the food chain with numbers swelling and diminishing as and when food supply allows.

Without any population control (other than food production) you may end up with an overcrowding issue. Going back to the Earth - the population density of aqauatic animals on the earth is far lower than that which any of us have in our tanks.

The closed system can be useful and quite possibly should be scientifically studied, if only to see how it fails, but it should not be a small product sold to the general public.

 

[sharkbaitwoohaha]

if the tarn is not a box which is more or less completley sealed from the surrounding atmosphere then it is not a closed system. just because it doesnt have any rivers or streams running into or out of it doesnt make it closed. the water table must be above the level of the bottom of the tarn and so it will exchange water with the surrounding ground.
dont like these closed systems. rubbish and cruel. people will get bored with them, probably because there isnt enough maintainence to keep them interested. nothing more than a funny looking paperweight. there were some at the trafford centre once with white cloud mountain minnows in. didnt like them then, still dont.

 

[raptorrex]

Are the Tarn's definitely closed systems (minus the lid of course)? Are you sure they are not exchanging water not just through precipitation and evaporation, but also though the water table that lies beneathe the ground?

If this is the case, it may mean that the "bad" things in the water as listed in other poss, are leeched out through the surrounding underground water, or at least the concentrations are kept in check because of these other potential avenues of escape.

My thoughts on the whole "closed ecology" is that it would take significant work to establish a balance in the system BEFORE it was closed - I don't think it would be possible to throw water, plants, inverts/fish in a tank, seal it and everyone's happy (even for a short period of time). there would be significant work required to establish that balance before it was sealed.

well in a way the Tarn is and is not an enclosed system. lol there is no egress of water. they are high in the Hills so are well above the water table. the bed of the Tarn is Slate, lol not the stuff we use for roofs, but more like the rocks and boulders you find at the sea side. so there in no seepage through the bottom. the water surface is in contact with the air. But as i stated they are in effect stagnant, so with no water circulation except through convection (is that the right word)? in effect the surface water is a lid below a certain depth , please don't ask me what it is as i have no idea, the water only receives oxygen from through the plants and animals that reside there. like i said yes and no.
lol and yes i know animals give off CO2 not O2 but the CO2 they give off is converted to O2 by the plants.

Your thoughts on these systems are as mine, but i would go further, an system such as Bio Sphere 1 was an attempt to make these thing work, but in my view it was far to complicated, covering too many different ecology's. hence its quick break down. it may prove in the end that the only self sufficient ecco system possible are planet sized. think of the size of a single bacteria, in comparison the the earth! now put that bacteria in our bottle, still with me? lol, the size of the bacteria in the bottle, in comparison to the space available, would make it seem enormass . so it may not be possible to contain enough in such a small space to continue a chain reaction, to provide self sufficiency

In the end it may not be possible to make these systems, based on the life forms we have on earth today! this make sense as these forms were created by the Earth itself, so in essence they were designed for earth, like anything it is often folly to use things that are not designed for the job!

So how can these things be made/

firstly you would, need to rein back your expectations for the range the system would cover, as far as i can see the only hope is to reduce the variables in the equation, in the hope that we can reduce it size.

then we need to look how life developed/s on our planet. as in evolution! through time the planet has gone through mass extinctions, these always lead to an explosion of new life forms and a change in the direction it is going.

Adaptive radiation evolution, (lol you think you have a headache reading this, you should try mine). I have a theory as to how this works, as populations reduce, caused by the extinction catylist, it becomes more likley that inbreeding will occur. we know inbreeding, causes genetic abnormality's. normally the defective prodgny
will die. just occasionally they survive, if they are suited to the new environment, they are likely to do more than survive. if they prosper, they may well supplant their predecessors. now if this happens to many lifeforms, it is Radiation evolution.

ok so now to follow that it would seem to me that these systems will need to evolve to survive, again size is a must here because if the system is too small all life will die off, but if it is large enough evens a tiny numbers of survivors will be able to repopulate the system. but they will look and act nothing like the forms when they were first put in. entire sections of the original ecosystem will vanish to be replaced by new and to us alien systems, that have evolved to take advantage of this new world/system.

ok that's my theory. im off to take a headache pill. this in not the definitive solution to this problem. it is a theory and solution i cane up with over last night and today. so it may be bo££ocks. but the logic is sound and the theory's it is based on are fact. i invite comment. incidentally i do know how to cycle a tank so don't bother. lol

 

[mjb]

andywg, your comments echoed some of the experience I've had and some of the input I've gotten from academic types who have created microcosms (e.g. for the space shuttle).

"stocking lightly" -- as in very lightly -- seems to be a key consensus point. The advice is to limit biomass and nutrients, particularly nitrates and phosphates. Excess nutrients can lead to algal blooms, which consumes oxygen which kills the macro-organisms. Fish are rarely used because they are bit compared to the containers. If a large animal dies it can act as fertilizer for an algal bloom. So I think that's why the commercial ones feature somewhat small shrimp, in low numbers, as the biggest inhabitants.

As for planting, there might be something to that. I personally have had more luck keeping macro-organisms alive in my test containers with vascular plants (as opposed to ones with just algae). They are not planted "heavily" by aquarium standards, but they are planted heavily by microcosm standards (given that many microcosms just use micro-algae).

In this setup animal population is limited by food production. There is NOT a lot to eat, and organisms may act differently than in a food-abundant environment.

Actually this is one of the similarities between some aquarium microcosms and Biosphere 2. In biosphere 2, calorie intake was severely limited. Even though the human inhabitants weren't really starving --rather, over 2 years the people just got thinner --, according to some anecdotes there was "atypical" behavior, such as food hoarding and theft.

If there's a theme to this maybe it's that "living within your means" ecologically isn't always pretty.

Cheers,

Martin John Brown
http/martinjohnbrown.net
email: mjb2000ATgmailDOTcom

 

[Neal]

My personal thoughts on this. I'm coming from both sides, listing the good points and bad points here.
If you planted heavily and stocked lightly, ammonia, nitrate and nitrite could be taken care of. What about evaparation of water? What happens when a fish/creature dies? It will rot, causing parameters to go off the scale if left long enough. What about diseased creatures that can't be treated? What about feeding them? I mean I know they can feed off the plants, but it's not really fair to just feed them that. What about trimming back the plants? They will become overgrown and thus you will not be able to see inside. What about getting stable Co2 to make the plants photosynthesise, and then having enough oxygen for the fish/inverts to live? If the system breaks down, there's no oxygen/co2 coming in from the top of the tank. What about stagnent water? You can't just shake it up and down to move the water about a bit. It's like living in a bath, which is getting the toxins removed by a pump, but it's still the same water. Like andywg mentioned, population control? You can't just let it get out of hand and then come to a giant breakdown. Personally, if I was going to do this, it would be a few snails in it, that's all. I hope people got both the good and bad points here, and don't just think i'm saying it's a bad idea. I think it should be tested on a snail only tank, but it would need to be altered to keep a good ammount of Co2, accompanied by a good ammount of Oxygen.

Neal

 

[MoMa]

what do you mean when you say that it is "dysfunctional"? What would they have had to do in order to "succeed"?

well, in the case of BioSphere, they neglected to add earthworms and other micro-organisms to the soil, effectivley giving the soil a limited "lifespan".
Those little orbs are a bit of a novelty, often sold in the giftshops of major aquariums in the States. The probem with them, and the problem NASA has been toying with, is that there is a limited life span. Yes the shrimp produce waste, and the waste is consumed by the plantlife, and the plantlife produce oxygen, etc. but each time "around" the output gets a little smaller, and eventually there is not enough to sustain life.
My suggestion to you, MJB (albeit one I'm sure you've tried), is to contact one of the manufacturers of these things and find out what changes they've made over the years in order to make these things last longer.

I have a similar (almost) set-up with live plants and snails, only fed by sunlight. However, it is "open-topped" and I perform water changes. I've yet to see those orbs with anything but tiny shrimp (read: glorified sea monkeys), and I'm sure the reason is that life cannot be sustained for long under those conditions.

Good Luck on your article, and post a link here when it's done, I'd love to read it!

Cheers,
MoMa






to get an idea of what he's talking about, click here.

 

[mjb]

Hi Neal -- thanks for chiming in!

I'll try to respond to your questions in order. Remember, I'm not saying anyone SHOULD create such systems, just that if one does, this is the way they (ideally anyway) work.

There isn't any evaporation of water to speak of -- the systems I'm talking about are completely sealed.

When something dies it decomposes in place. For better or worse the decomposition products become part of the environment inside the microcosm. If a disease was involved, yes, that disease is part of the system. That might mean that all individuals of the species most susceptible to the disease will die out. That will alter the ecological relationships in the tank... hopefully in the direction of a stable system, but it's not guaranteed.

Plants do not necessarily get overgrown. Remember they are limited by nutrients (notably light, but also chemical nutrients).

CO2 is produced by animals (and also is produced when plants metabolize). O2 is produced by plants during photosynthesis. This is the basic cycle that microcosms demonstrate. But available carbon does tend to be limited, so some microcosm makers have tried to increase CO2 in the systems by throwing in carbonates just before sealing.

Population control basically comes from nutrient limitation, as I wrote to andywg.

Anyway, you are right -- it is like living in a bathtub... a bathtub inside a hermetically sealed bathroom. It has very little in common with the kind of aquariums that people like to keep at home, which are not just open to the air but require maintenance on some level.

These microcosms have no maintenance (except for the provision of light), and for better or worse the community inside is changed by that.

Cheers,

Martin John Brown
http/martinjohnbrown.net
email: mjb2000ATgmailDOTcom

 

[raptorrex]

what do you mean when you say that it is "dysfunctional"? What would they have had to do in order to "succeed"?

well, in the case of BioSphere, they neglected to add earthworms and other micro-organisms to the soil, effectivley giving the soil a limited "lifespan".
Those little orbs are a bit of a novelty, often sold in the giftshops of major aquariums in the States. The probem with them, and the problem NASA has been toying with, is that there is a limited life span. Yes the shrimp produce waste, and the waste is consumed by the plantlife, and the plantlife produce oxygen, etc. but each time "around" the output gets a little smaller, and eventually there is not enough to sustain life.
My suggestion to you, MJB (albeit one I'm sure you've tried), is to contact one of the manufacturers of these things and find out what changes they've made over the years in order to make these things last longer.

I have a similar (almost) set-up with live plants and snails, only fed by sunlight. However, it is "open-topped" and I perform water changes. I've yet to see those orbs with anything but tiny shrimp (read: glorified sea monkeys), and I'm sure the reason is that life cannot be sustained for long under those conditions.

Good Luck on your article, and post a link here when it's done, I'd love to read it!

Cheers,
MoMa






to get an idea of what he's talking about, click here.

problem with this type of system is that, the content is just not diverse enough to sustain itself!