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Discussion Starter · #1 ·
My friend and i have a biology project called an eco-column. We have a large water cooler jugs (these: http://poundperpound.files.wordpress.com/2010/11/water-cooler-jug-40lbs.jpg) and we need to fill it to sustain itself. It will be connected to other bottles as well, so Google eco-column for a better idea.

Any way what can we fill it with, we were thinking phytoplankton, zoo plankton, small fish and possibly some triops. And we need some kind of aquatic plant foor food, any ideas?
 

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I've read up on that eco-column project to understand just what you're talking about...

I would not recommend stocking much in your aquatic portion besides algae and aquatic plants. There will be other microscopic organisms whether you intend for them to be there or not though...

Here's why I would think fish, etc are a bad idea...

1) These systems don't seem to mention the role of the nitrogen cycle in aquatic environments, which is essential for keeping things like fish alive. Without establishing the bacteria necessary, you cannot keep larger organisms (like fish) alive.

2) It looks like the water you add to the aquatic portion is draining through one or more portions before it reaches the aquatic environment. This means that you are adding water that is very high in dissolved nutrients to your aquatic environment. This will contribute to the overgrowth of algae, and could introduce ammonia into your water which would harm aquatic organisms.

Particularly concerning would be if your water was draining through the compost and eventually reaching the aquatic environment. This water would certainly ammonia (which is toxic to most aquatic creatures), amongst other potentially harmful stuff.

3) It doesn't look like there's much air circulation in these systems. Air circulation is important for terrestrial organisms (plants, too), decomposition, and aquatic environments.

If you can address these problems so that you are establishing a nitrogen cycle, you are not draining water through other systems into the aquatic system, and the aquatic portion has access to fresh air, then fish would be viable. However, you still need a way to deal with decomposing fish waste (regularly maintenance? Aquatic plants?), also, enclosed environments are never truly 'self-sustaining'. You will eventually have to dismantle things, so be prepared for that.

Afraid that's all I can suggest given that I'm not particularly familiar with this project, or with you or how experienced you are with aquariums, or what school level this project is for.
 

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Discussion Starter · #3 ·
Ya, thanks for the input, I wasn't thinking fish were a good idea that was my friends input, but as for the first tier, will phytoplankton work, or algae? Any recommendations on a plant to put in to supply the triops with a food source?


O and I'm a Freshman (Highschool) And it doesn't say where you are from so if you are international that's 15 years old.

The teacher expects it to self sustain it-self for at least a week.
 

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Make it brackish and add algae and Opae Ula - Halocaridina rubra. Although they won't reach their maximum lifespan, they will make it easily for 3 years.
 

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I think the key to making something like this work is to keep the livestock small. A small habitat can only produce just so much food, and only deal with just so much waste. Do not overload it.

Triops sound like a good idea. They are small, and eat a lot of different things, so should be able to find food as the system matures.
I would think something really small, like single celled algae (green water algae) would probably be the best food for the small animals you are thinking about. Green water algae is actually any of several species of single cells that photosynthesize. To get a culture going I have often used the water from an aquarium and just set it in the sun. Add used aquarium water as needed. (Your set up might get some nutrients from the compost jar) The green water algae seems to be all around, and just gets itself going in the bright light and nutrients from the aquarium water. Unfortunately it makes it difficult to see the livestock, unless the critters keep eating the green water algae. Daphnia will eat green water algae. They will reproduce so fast you will have to add something to eat them.
Also look into Fairy Shrimp. There are many species, so make sure you are getting one that is adapted to the water chemistry you are using.
 

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if your teacher expects it to last a week, your teacher is payed more than he's worth

a human and our huge appetite can last a week without food.

if your tank/bottle can last a month without input beyond water, your doing good.

i'd expect it to take many months to get it setup though.

unless you've got an established aquarium to start with, then your salvaging everything you can fit into your jug that you can. ... to give you a few month headstart.

most difficulty is going to be timing.
the more successful you want your tank/bottle to be, the more time it's going to take to build it because your waiting for everything to establish itself.

unfortunately, personally, i'd say your a year behind.

your nitrogen cycle bacteria is about 6 weeks to establish
plants,depends on if they're just to deal with CO2/O2 + nitrates (complete nitrogen cycle) - short time, ... or if you want something that will last with herbivores in the tank.

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might be simpler to pay attention to the largest critter you want in there, what does it eat ? (carnivore, herbivore, omnivore (carnivore or herbivore tendencies)

for plants (considering herbivore dietary preferences)
-nutrients, are there enough nutrients being provided/added to the water column &/or substrate to provide the plant with what it needs to survive & thrive

for critters that are eaten, ... what do they eat ?

at the bottom of the list your going to have a cycle of bacteria to plants (as the bacteria die and release waste into the water column and make nutrients directly available to plant roots

or there is detritus from poop and everything that decays, ... all these needs to be broken down, (which feeds the nitrogen cycle) and the nutrients are made available for everything which can take it's nutrients from the water column or from the substrate.

and don't take the food pyramid too seriously, ... else your self-sustaining biology project will fail. it omits detritus feeders (those that are sustained by eating the dead and decomposing things) and it omits parasites, ... which some feel are at the top of the food-chain above everything else.

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i've got a bowl at home (glass round fishbowl) it's got micro-worms, a few smaller snails, algae, ... and an abundance of nutrients.

i can't see the nutrients, any detritus doesn't accumulate before bacterial and microworm activity reduces and moves the nutrients into the water column

everything is doing well, the microworm population is hard to find as they need a surplus of additional food for their population to bloom (actually feed the bowl) and then the water looks more cloudy than anything. otherwise microworms are thinner than a hair and only a mm long or so, ... very hard to find till you notice them slowly moving along the glass. then you know what to look for and you see them over everything.

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if you want to look up how difficult or easy it is to build a self-sustaining environment, look to pages on the net about culturing different things, could be daphnia, could be microworms, could be phytoplankton.

one i came across involved one barrel with goldfish (they poop a lot), feeding greenwater, the greenwater would be moved to a bucket with daphnia.

this isn't a single tank, but a system, ... in the wild this tends to be the case, the largest lake is going to have different critters that stay by the shore, different critters live in the depths and others just live in the upper layers of the water, more critters living on or just above the surface. different critters living in the areas that feed water to the lake from the areas that water leaves the lake. there's trees or plants dropping leaves and branches into the water providing both places to hide and food... these areas while using the same water (generally) are spread far enough apart that each operates generally independently from others.

if one area was removed maybe the lake would be unaffected, maybe it would be the undoing of the whole lake, ... maybe the lake would just change and adapt.

a single tank for a self-sustaining system is hard
an easier one is several tanks each one feeding the next tank for a complete system if your moving something from the last tank into the first tank to keep the cycle going.

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whatever your doing to do, don't underestimate bacteria in the tank, both as a food source & as the starting blocks to keep everything in the tank going & alive.

they will break down detritus, release nutrients for anything in the water column to use, and provide food for the smallest critters.

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food for the smallest fish fry and baby shrimp is also bacteria & phytoplankton sized - something to think about.
 

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clams can starve over the course of months, even up to a year before it finally dies.

while not for class, if you look around there are many individuals trying a self-sustaining single tank or system. well a very small few, but we're out there.

it's not a quick experiment, it's going to take months or longer to find out if your successful, or even pointed in the right direction.

some are trying to establish from a food chain system using what's talked about in the food pyramid, this will never work, it's too simplified, and it's not balanced.

i'm looking at nutrients and starting the food web from phytoplankton & detritus feeders, clams are risky, they're large and may eat all the phytoplankton (i have no idea, but something i'm concerned about)

everything going into my tank is in one way or another cleaning and maintaining the environment. building a balanced environment with maybe a few fish ontop of the pyramid, but those fish have a natural dietary preference based on balancing what is produced in the tank.

so far (for a breeder size tank)
-phytoplankton (dono if i want specific strains or general whatever i can get)
-intentionally adding algae (thread algae)
-moina
-blackworms
-snails (malsian trumpet snails)
-shrimp (amano)
-duckweed
-plants, (various)
-clams (unsure if i want clams or not)
-fish with the right dietary preference (i'm still guessing about what fish to consider)

i want as much activity going on in that tank as i can get. activity that does not depend on other levels, but can support it to provide additional food for the next level, to provide it faster, and of higher nutritional value.
it's a tiny space to try to have an ecosystem that can support any fish where the tank does not require any additional input (feedings)


-moina (as it ages) has a high protien content, and reproduces quickly
-daphnia reproduces slower
-rotifers have a very low nutritional value - actually most of rotifers nutritional value is the food it has just eaten, not it's own inherent nutritional value.

algae can remove nutrients from the water column very efficiently, and grow rapidly because of this, and the shrimp will eat the algae. algae is a given in any tank, it's either under control or it's not (and you only see it when it's not under control)

duckweed has a high protein content (dry weight)

invertebrates & snails want a high PH, else their shell will dissolve (snails)
CO2 will lower the PH
in can't get my PH above 6.5 :( i want it 7.0 - 7.5

fertilizers for aquariums are notoriously low in phosphates, ... great to restrict algae, not so great if you want healthy plants. phosphates become very hard to come by and plants show deficiencies.

i am in the process of putting everything together for this breeder tank, till then i am still learning with the 29 gallon i have. and plants are great for showing you any deficiencies you may have.

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when it comes time to start the breeder tank, it's going to go through several steps, initial cycle, adding each part letting it establish, even thrive, then adding the next part.

one forum the member talked about recommending a year or two to set up things before trying to convert it to a self-sustaining system. i'm impatient, i'll expect 3-4 months (including tank cycling)

add plants
add phytoplankton, wait for water to turn bright green, add moina
add chopped algae, wait for algae to be a significant issue, add shrimp
add add detritus, add blackworms, add snails
wait for plants to show it's turning into a forest, add fish (just a few)

but that takes a while for plant growth to get that wild
(not trying - would happen faster if i was trying) took my tank about a year
 

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the eco-column, ... just my thoughts, and i'm just going on pictures and descriptions i just started to look at today, ... the spider is dependant on the fly, the fly is dependant on rotting compost, the water is the bottom is a place for excess water to drain (i wouldn't trust it to be healthy water to put a fish in.)

the rotting compost will only be moist for as long as the water does not drain into the bottom, then it will just mold and i cannot see that sustaining flies or bugs the spider will depend upon.

not calling myself educated on the subject, i just deal with freshwater planted aquariums.

aquariums are easy, we don't have to control humidity, terrestrial life is specialized to want specific humidity ranges, some want it dry, some want it almost perpetually 90% or more humidity.

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the earth is (i think) 3/4 water (surface area)
without mans intervention, estimated 80% forested
deserts being less than the 20% remaining (including the arctic poles - rated as deserts)

it's an interesting idea to put everything together into a simple column, so many thoughts, so many ideas, so many worries i know nothing about. in my ignorance so much i think about that could go wrong.

so i stick with aquariums :)
 

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I think you will shine if you show up with a so-so setup AND explain all the things that make it impossible. Looks like there is enough information in this thread to make a beautiful case.

If you present everything in a great way you will win everybody. Most teachers like to see you have put mental energy in the project. That is what you will show them. Just make sure you don't make your friends that brought actual nice little setups look like dummies too much.

Good luck.
 

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I must agree with Niko and Flear here.

Demonstrating the opposite really takes courage and a good head on your shoulders. Demonstrate the hobby in its most current state and you may even make new hobbyists or newer & better activists. The real creativity & smarts is making your teachers and classmates understand that maybe they didn't quite understand. I say work this angle. As Niko says, be careful: Don't let them think for a moment you're calling them dummies. Human nature tends to do that.

A truly self sustaining system is a pipe dream, but the inspiration is definitely useful for pushing the boundaries of our understanding and putting to use sound limnological concepts.

Here's a little something I wrote ages ago that might help with philosophical aspects and why your timing is... ....interesting, to say the least:
https://sites.google.com/site/skepticalverdure/home/what-s-all-this-then

Good luck! We're rootin' for you!
 

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i'm only going to partly agree with the statement that a self-sustaining system is a pipe-dream

there are eco-spheres
a tiny piece of coral (i'm pretty sure it's a specific type)
brine shrimp (specifically brine shrimp)
whatever other cultures there are inside
"if" you have all that, there is rumor that some have survived and are still living after 10 years, ... that's a lot of "ifs" for the possibility that maybe your doing all the right stuff outside of the container (light, temperatures, stability) for the slim hope that the balance inside the sealed container keeps itself going.

personally, a successful self-sustaining tank, i'm only counting as one i don't have to feed. i'm still going to have to top up the water (but not do water changes), populate the tank with it's own cleanup crew (so i don't have to do any maintenance or cleanup). any fish or critters 1" and up i have no expectations that they'll survive to breed a sustainable colony. first generation fry would eat food sources into extinction that were only capable of maintaining the select few adults.

maybe coral, without a symbiotic algae needed to sustain itself, greenwater, zooplankton, larger tank, but your still going to have to add minerals and nutrients that eventually go into the coral skeleton else everything is going to die off, ... again, very specialized, and your still adding.

i've been told i'm lazy because of this idea, i've been told it's not healthy for the inhabitants of the aquarium. it's been a year of looking up information & asking questions, going against the norm. a year of having ideas doing research and realizing that some ideas were bad ideas, a high willingness to change my ideas, and come out of it knowing far more then when i started. i've learned lots, what eats what, what is needed for everything to survive. and it's healthier than all the stuff we buy and do to maintain our tank., ... right now i've got just enough knowledge that if i insisted i know enough and didn't need to learn anymore, i'd kill everything in the tank. so i've got lots more to learn

far more learning (most people just want things handed to them)
far more planning (most people just buy whatever, and buy more because there's something else that needs maintaining)
smaller critters (most people want something large, bright, ... often larger that what their aquarium should handle)
specialized critters (most people just buy what looks nice)

true self-sustaining (aside from water top-up) inside our homes with aquariums we can buy or build, are going to be populated with scavengers, detritus eaters & critters small enough we'd easily overlook them (just a few millimeters in size)

timeline:
weeks - if you want to and do some research, anyone can do and it will survive for a few weeks
months - some have made the attempt, it's very few and very far between you'll hear about any of them. but they are out there.
years - so far i've only heard specialized parts of certain setups have survived for years without maintenance of those parts. not entire tanks though, i've never even heard rumor (other than the eco-sphere)
decades - that's my rule of thumb if you've got something that is self-sustaining and it's still going strong, if a species has a life expectancy of 3 years - more if the life expectancy is longer.

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a self-sustaining system of tanks, one feeding into another so populations from any of the feeder tanks can be sustained, and they can be expanded on. but it's a system of tanks, and requires an equal amount of work to move things from one tank to the next. and moving things back to the starting tank to keep the system going.
 

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there are eco-spheres
a tiny piece of coral (i'm pretty sure it's a specific type)
brine shrimp (specifically brine shrimp)
whatever other cultures there are inside
"if" you have all that, there is rumor that some have survived and are still living after 10 years, ... that's a lot of "ifs" for the possibility that maybe your doing all the right stuff outside of the container (light, temperatures, stability) for the slim hope that the balance inside the sealed container keeps itself going.
I can attest to this. I have a small EcoSphere(tm) that still contains live shrimp and a live plant after 5+ years!

It is a fully sealed glass ball. The only inputs are:
1. Light
2. Temperature
3. Other e-m radiation
4. Gravity

I count it as self-sustaining, though only for the natural lifetime of the shrimp. It's a very simple ecosystem, and doesn't illustrate as many processes as these school projects intend to. For example, there's no reproduction of the higher animals (the shrimp).
 
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