# A tentative plan for self sufficiency



## BigTom

Right... this may turn into a wall of text, so please bear with me!

I gave up fishkeeping about a year ago due to starting a PhD which involves being away from home for 6 weeks at a time, 4 times a year. However, I've recently started thinking if there was a way I could run something lowtech and self-sustaining that could tick along happily without me - now I know there's always going to be a risk of somethin unforseen happening, but I do have flatmates who could step in should everything explode or something   

I've drawn a lot of inspiration from this site - http://www.tuncalik.com/2009/09/biotope-in-my-study/ which I originally found when I previously kepy scarlet badis.

Basic idea is a shallow tank, something like 90x90x30cms, probably custom made unless I can find an old terrapin tank or something, with a vaguelly asian biotope.

Filtration by emergent and 'boggy' plants (I'm thinking quite a lot of purple bamboo and similar grass-like plants, plus whatever else I come across that might fit in), some water circulaiton from a koralia powerhead or similar. Would like to try and encorporate a hairgrass lawn (yeah I know, might be getting over-ambitious here!), so was thinking about getting a cheap old single 150w MH arcadia pendant off ebay and doing a dry start, could then raise the light much higher once flooded to cover the emergent plants and hopefully not cause massive algae problems.

Once flooded, seed the tank with a bunch of inverts - daphnia, gammarus, shrimp, blackworms etc to act as food for a group of Dario dario (Scarlet badis) or other micropredator to be introduced further down the line. WIll add plenty of leaf-litter to keep the inverts going and encorporate a small refugium hidden amongst the plants and hardscape at the back to try and prevent complete wipeout once the fish are in.

Would also be keen to add some freshwater gobies if (when!) I end up with algae growth. Will slowly increase fish stock to try and find a balance with the inverts/algae.

Biggest problem will presumably be water loss through plant uptake and evaporation... I'm hoping covering the tank with acrylic with holes cut out and overed with clear plastic domes where the plants emerge will keep it in check while away, I'm sure I could ask my flatmates to top up the water occaisionally.

Does all this seem feasible or have I gone completely mad?   

I'm a little worried about balancing nutients for the plants - was planning on using topsoil/garden soil capped with sand, any advice here would be hugely appreciated. I'm not going self-sufficient for the sake of it, so can happily dose when I'm home if needed.


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## a1Matt

Daryl posted a link to that tuncalik site a few months ago, I find it really inspirational too 

Your idea seems perfectly feasible to me. 

Like you say it is a balancing act, not just nutrient wise, but the tank as a whole.
To make the balancing act easier you could...

- not add any light at all.
- not add any fish at all (just inverts).
- add a filter. (with the low bioload it will rarely need cleaning, it is then easy to get it down to every few months between cleanings).

Not saying you should do this rather than your plan, just putting out another thought on it.  

I actually really like your plan  8) 

Dy start with a halide sounds cool.  Not sure how the carpet would fare long term in uber low tech, but kudos to you if you give it a go   

and the refugium is a cool idea. (It is something I'd like to try one day myself, so this strikes a chord).

Except for the domes for the emergent plants, they sound like an eyesore.  Could you have a cover glass for part of the tank, let the emergent's poke out, work out the 'standard' evaporation rate and ask your housemates to 'water the plants' for you? 

For the submersed plants I recommend ferns and swords, I have found (in a low light low co2 environment) when their is a lack of nutrients they just stop growing and start again when they appear again. They get a little GSA, but other than that as long as the tank is stable they are pretty much bullet proof  

I've also seen a few secondhand terrapin tanks on ebay


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## BigTom

Thanks for the feedback Matt.

The tank cover would only be in place when I was away, and as the tank will be in my room it isnt an eyesore for anyone except the fish. As long as the extra humidity doesnt knobble the emergent plants then it shouldn't be an issue.

Defintely want to have fish, even if its super-light stocking levels. Afraid I'm a fishkeeper first and gardener second!

I guess no reaosn not to have a filter really, although I don't see there being much need for one, and the lighting regime will be very much trial and error - if nothing else the MH should keep my chilly Edinburgh room warm in winter 

Hopefully should be able to get this rolling in early October (I'm away on fieldwork til then), would give me about a month to dry start before adding water and inverts.


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## a1Matt

The cover sounds like a good idea now    
I do not know about the extra humidity... I guess it may depend on the plant species chosen.
Maybe someone with experiental knowledge could jump in to comment on that.

If you go ahead with this, I look forward to hearing updates...


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## BigTom

Pretty set on this now, although if anyone has any further input it'd be appreciated.

Away soon on fieldwork til end of September, but hopefully will su a  journal thread after that.

BTW Matt, how are your chocs doing? They're one of the species I was considering for this project, but think it might add another layer of difficulty.


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## a1Matt

I keep them in blackwater conditions... I change the almond leaves in the filter out every couple of weeks, WC's weekly with pure RO. Maintaining a TDS of around 100 and keeping the plants healthy (or even just alive at times    ) is challenging.

Probably not a good choice for a tank left to it's own devices for long periods of time!

Thanks for asking about the ones in my tank 
The original batch I bought are doing fantastic.  I added another batch a couple of weeks ago, and it will take them a few weeks to settle in... a couple of them are struggling at the moment. Gory details in my journal.


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## dw1305

Hi all,
I'm away from home and have limited web access, but I think it is quite feasible. I'd have a filter, how about a hamburg matten filter? or just a big foam block and powerhead? I also think _Dario spp. or Trichopsis pumila _(if you have a heater) or any of the smaller Betta sp. would be ideal fish. I think you will need a cover for when you are away, and I think a lawn is too ambitious, dry start may be all right, but I'd probably go lower light and a moss carpet. I would stay away from Gobies because of their higher O2 requirement (I'd go for shrimps and snails). I kept Paradise Fish in the water tank in the glasshouse (open topped and full of Cyperus plants) for many years. They survived total neglect when I was away from work for 16 weeks following emergency surgery, but not a contractor turning the heating off when it was -12oC outside.

cheers Darrel


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## Fred Dulley

I've always wanted to do something like that. Go for it!


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## BigTom

Well, this is go!

Custom 36"W x 12"H x 36"D braceless tank ordered and due in 2 weeks, and I've got a preliminary plant list and scape planned out, and a 70W halide on the way (Â£20 off ebay).

Planning on using John Innes or similar as the substrate, but not sure what to cap it with. Need something cheap and 'soily' looking.

Still need to decide whether to put a filter in, I was planning on just adding a Koralia evolution for some nice broad flow, but perhaps a mattenfilter is a good idea. Any recommendations for a silent powerhead?


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## a1Matt

BigTom said:
			
		

> Well, this is go!



Great   



			
				BigTom said:
			
		

> Still need to decide whether to put a filter in, I was planning on just adding a Koralia evolution for some nice broad flow, but perhaps a mattenfilter is a good idea. Any recommendations for a silent powerhead?



How about a Koralia in combo with an air driven sponge filter (or 2 for redundancy when cleaning them)?
This is what i am considering for my next tank in the hopes that it gives a good combo of flow and filtration for a low wattage and small footprint in the tank


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## dw1305

Hi all,


> Planning on using John Innes or similar as the substrate, but not sure what to cap it with. Need something cheap and 'soily' looking.


I'd probably go for the Moler clay "Tesco lightweight cat litter" from "Robthecop"s thread <http://ukaps.org/forum/viewtopic.php?f=17&t=13018>  I think whatever you cap it with will end mixed with the soil over time.

I would probably mix the JI with some sand or other inert substance, otherwise I think you will have a really big ammonia spike initially and it will take a long time to settle down. I like a fairly lean mix, but I use 80 - 90% silica sand and 5 -10% leaf litter and loam based media. 





> air driven sponge filter (or 2 for redundancy when cleaning them)?


 I'd definitely go for 2 sponge filters. I'd probably combine the filtration and water movement roles, and use a maxijet & ppi10 sponge details here <http://ukaps.org/forum/viewtopic.php?f=38&t=8524&hilit=+maxijet>.

cherrs Darrel


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## BigTom

Tanks here 

3'x1'x3', loving the dimensions! Scaping it is going to be awesomely fun.

Sadly I'm away again in 2 weeks so might have to wait til I get back in December.


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## a1Matt

BigTom said:
			
		

> Tanks here



Woop!


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## ghostsword

Hi.. 

It is a great idea, and I am actually trying something very similar, with a 50cm by 30cm by 30cm acrylic tray. For the plants use Hygro's, humidity is not an issue for them, as long as they have wet roots, they are happy. Also Draecena, and Syngonium's, they grow well with just wet roots. 

For filter, you can use aquaball, from eheim, they are very good, and if you only come home once a month, clean it then.  

If you setup plants at the back with some mesh next to it, the shrimps, worms et all, can survive while still provide some food for the fish. 

Your flatmates could top up the water lost to evaporation every two days or so, and the tank would be ticking along just fine.


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## Mxx

Here is a similar thread which had some good feedback. http://www.plantedtank.net/forums/gener ... sible.html

Do you have a source for the small invertebrates you'll be adding, such as daphnia and cyclops? I'm looking for some myself for a slightly similar tried, and just tried growing a sample from my pond but all that came from that was some dodgy looking worms.


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## BigTom

Hi Mxx,

This tank has now been running for 9 months (you can see progress in the journal here - http://ukaps.org/forum/viewtopic.php?f= ... &start=130).

Currently supporting 4 otos, 7 _Bororas maculata_ and 6 _Parosphromenus sp. 'sintang'_.

I found that cylcops and various other inverts arrived all on their own, I've added a bunch of different daphni and ostracods from various sources (friends on forums, and there's a guy who operates a business called 'Daphnia Direct'). The most successful things seems to have been some little black ostracods, I have no idea where they came from, but they're all over the floating plants and wood. The baby cherry shrimp are also an important food source for the Paros, I believe.


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## dw1305

Hi all,


> The most successful things seems to have been some little black ostracods, I have no idea where they came from, but they're all over the floating plants and wood.


 Ostracods appear in the most unlikely places, I've had them re-appear in trays etc that haven't had water in them for several years. I believe that they can survive as a mixture of "dehydrated juveniles", "encysted adults" and as eggs. Your ones may be the famous _Eucypris virens_ <http://my.opera.com/Ukwildlife/blog/ostracod-eucypris-virens>, I often get them in the _Daphnia_ buckets.

Are you back in Edinburgh? if you are I'll try and send some more of the "unknown shrimps" next week, hopefully with a bit more success than last time.

Darrel


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## BigTom

I get back to Edinburgh on Tuesday Darrel, that would be great.

I might break out my super-macro kit sometime this month and try and get an inventory of the various critters.


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## Mxx

Hi Tom, I noticed your post on plantedtank.net, which is quite an active forum as well. One of the links provided in that thread had been one for this store http://www.aquaculturestore.com/fwinverts.html which have different invertebrate species available, including a Freshwater Plankton mix consisting of 6 different species of invertebrates. 

I'd been considering doing a similar 13 gallon tank/bowl, and had thought of ordering that mix in order to get an initial food source available to the fauna. Ebay has some large acrylic spheres available, for use as lights but which I expect I could retrofit for fish and add a small spotlight and heater to. 

I was considering doing it either of two ways - one vessel with small similar fish such as Endlers and Badis, as well as shrimp, in the hopes that Endlers would be able to in part subsist off the algae and that the Badis would help keep the Endlers and shrimp population in check. And I was also considering sealing the top instead and having just Hawaiian Volcano Shrimp or Cherry Shrimp, which would mainly subsist off the plant and algae growth I believe. In that way I wouldn't need to top off, and all that I'd need to do is add light or put it in a window. I expect the invertebrates and plants would necessarily achieve some sort of balance between oxygen and CO2 production and usage, potentially allowing each to thrive and providing more CO2 to the plants than they'd be able to obtain in an open vessel or tank. 

At the moment I have a trial with four 5 litre jars which I'm going to test out in various states, sealed and unsealed, high plant bioload and low, and topsoil substrate or not, to see how each fairs. But they're in my office which isn't heated particularly well, so I'm about to pick up a reptile heating mat to put underneath them for the winter. If I can get them to a stable state then I might try to add some shrimp to those as well. I think I'll need to include at least a nerite snail if I want the container to stay clean, but worry that they'll be competing then against the shrimp for available algae...

But please do let me know if I could perhaps share a sample of your invertebrate mix as well, so that I wouldn't need to buy that from the other side of the planet!


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## dw1305

Hi all,


> And I was also considering sealing the top instead and having just Hawaiian Volcano Shrimp or Cherry Shrimp, which would mainly subsist off the plant and algae growth I believe. In that way I wouldn't need to top off, and all that I'd need to do is add light or put it in a window. I expect the invertebrates and plants would necessarily achieve some sort of balance between oxygen and CO2 production and usage, potentially allowing each to thrive and providing more CO2 to the plants than they'd be able to obtain in an open vessel or tank.


I wouldn't recommend any sealed container, the Hawaiian Volcano shrimps (_Halocaridina rubra_) don't really live in the sealed "Ecospheres", they are just really tough and die slowly. In a normal 13 gallon tank you should be able to keep a population of  a small fish species and RCS as long as you have a lot of plants and some biofilm development, probably with moss being the most important. Small tanks are inherently unstable and more dificult to manage.

I'd probably go for _Dario dario_ or _Trichopsis pumila_, but Threadfin Rainbows, _Pseudepiplatys annulatus_, the small Anabantanoid species, _Corydoras pygmaeus_ etc. would do. I wouldn't go for Endlers as you won't be able to keep them in check.

cheers Darrel


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## Mxx

I'd read that about the Ecospheres, but that seems to be as a result of such a limited food/biomass supply which they set those up with initially. I expect they have to do it that way to keep algae from quickly covering every surface and becoming unsightly, so you'd have to control for that in a different manner. Perhaps with more food available, as well as the appropriate amounts of buffering compounds including some crushed coral/dolomite, they'd nevertheless be able to thrive. 

 A very hardy plant such as Java Moss is probably best, and I have some of that, as well as some Pellia, and just received some Christmas Moss and Flame Moss, which for the time being still however look like heck...

You don't think Dario dario wouldn't keep Endlers in check? Well scrap that ideal then, unless I was to limit it to males. 

This is the spherical 'bowl' I was considering trying this with eventually. http://www.ebay.com/itm/18-GLOBES-HALLO ... 2296wt_952


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## Garuf

Mxx said:
			
		

> I'd read that about the Ecospheres, but that seems to be as a result of such a limited food/biomass supply which they set those up with initially. I expect they have to do it that way to keep algae from quickly covering every surface and becoming unsightly, so you'd have to control for that in a different manner. Perhaps with more food available, as well as the appropriate amounts of buffering compounds including some crushed coral/dolomite, they'd nevertheless be able to thrive.
> 
> A very hardy plant such as Java Moss is probably best, and I have some of that, as well as some Pellia, and just received some Christmas Moss and Flame Moss, which for the time being still however look like heck...
> 
> You don't think Dario dario wouldn't keep Endlers in check? Well scrap that ideal then, unless I was to limit it to males.
> 
> This is the spherical 'bowl' I was considering trying this with eventually. http://www.ebay.com/itm/18-GLOBES-HALLO ... 2296wt_952


I'm sorry but you're fundamentally wrong, a closed system can _never_ thrive, infact a lot of research still disputes whether they're even possible to create because of a phenomena called entropy, it's a universal truth, simply put this means that matter will always decrease to it's smallest form and that available nutrients too, will also ever decrease, forget this notion of self sustainable or some perfect representation of an eco-system because all these notions are fundamentally floored because we do not live in a closed system and there's no notion that it will fall into balance, because simply put the world just doesn't work that way.


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## Mxx

Sigh... okay, so why and how? 

Your opinion is that this doesn't work, but I'm finding the reasoning rather dubious. A specific thermodynamic property is  a very different thing from a universal thing applicable to everything, and entropy in ecological terms refers just to the aspect that the amount of energy density in an area will tend to level. 

With all due respect, I must express my own opinion that your interpretation seems a simplistic over-generalization, and were it true then life would not exist anywhere. 

As for closed systems that thrive, go to Wikipedia and see Earth, or our solar system in case sunlight is necessary to include in your calculations. But I'm pretty sure I can get algae, bacteria, and perhaps some invertebrates to successfully live for a decent while in a jar, and maybe even some java moss while I'm at it. If there are specific parameters that you believe would become problematic in time then I'm happy to discuss those. 

Perhaps it's the case that some years down the line the entirety of some compound necessary to perpetuate the circle of life will have been bound into a form which such a small system can't itself reformulate, but I've yet to hear of anything to that effect, so perhaps it's best to have experiments test that out.


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## Garuf

Really to answer it requires much more in depth study, I can assure you the earth is not a closed system, it's refereed to as a closed system when one talks about transportations of water or so on but it's not a closed system, if it were a closed system life would be impossible to created let alone thrive, this is because we live in a permeable atmosphere and all supplies are finite right down to freshwater. 

The reason for me saying you cannot create a sealed "ecosphere" type environ is justified by entropy and the break down of matter ever decreasing, each generation of life will deplete the amount of nutrients contained and all you will create is a system where the suitability of conditions for live ever decrease until the hardiest critters can't survive any longer, each successive generation of life decreasing in numbers and vigour because the energy supply is totally depleted of it's usable compounds. Also decomposition isn't a complete cycle that can take place at a speed to release nutrients back for the next generation, it's a long and drawn out process, the net energy of which decreases because all living reactions produce heat which will deplete available nutrients and will not return, otherwise what would be created would be akin to a perpetual motion machine. The other matter to point out is that the atmosphere is extremely important in almost all earth systems even the seas, without a atmosphere carrying more nutrients into the system it ultimately fails.

If you were however to not seal the "jar" it's another story entirely and these non-sealed minimal input systems like those that Tom created are very successful and can survive for a much greater period but you must remember that they are not a closed system and a net gain will be vital to their longevity. 

For a much more in-depth study I can suggest the works of A. G. Tansley who discusses why our notions of order and system within ecology are mostly wrong.


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## Mxx

It seems we're going to conclude in disagreement on this topic. For while I believe I do see more where you're coming from now, I still think the comparison is in gross terms valid. And not to be argumentative, but I do happen to enjoy this topic as well as testing the philosophies of it. 

Your description of entropy unfolding in an ecosphere cut off from all external inputs and eventually running out of energy would be correct. However, the moment we put an ecosphere on a windowsill it would receive a substantial input of energy daily in the form of light, and the plants and algae would be transforming that into other forms of energy which continually replenish the system. Similarly, think of the earth as just a big planet sized jar, which keeps water and gases in, but lets light and heat both in and out. And so long as the sun doesn't burn out, both will continue to receive the necessary energy input to fuel life. 

I'd been in part inspired by Diana Walstad's book in this regard, which basically boils down to animal inputs and outputs = plant inputs and outputs. And life in our little 'jar' seems to have been perfecting that for about the last four billion years, with at least a reasonable level of success achieved finally in the last billion years, apart from one invasive species now - Homo sapiens - which are currently threatening to severely disrupt the system's stability. 

I'm unsure though what nutrients you suggest are being replenished via our atmosphere, and the decomposition of organic compounds is something which is happening continuously and supplying a constant recycled supply of those nutrients, regardless of how long it takes but at least for the nitrogen cycle doesn't happen to take very long. There are however certain other nutrients and compounds, such as potassium for one, which I'm not quite sure of how it works through the system and in what forms.

I'm more concerned with whether the life processes will tend to produce gases and increased pressure over time, turning my ecospheres literally into timebombs...


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## OllieNZ

To apply an engineering slant to the project, I think it all comes down to scale. Keeping a shrimp in such an environment would be like locking an elephant inside the biodome at the Eden Project and expecting the plants to reproduce at a rate that would keep the elephant well enough fed to live a long happy life. If you look at the earth the individual organisims are tiny compared to the system. I wouldnt expect to be able to keep anything you dont need a microscope to see alive for any length of time. The other issue is time, scale things down and they speed up. Look at a forest, leaves are dropped every year(or at a slow constant rate in an evergreen forest) and provide decaying matter to turn into nutrients for the system. You would need to keep a fast propagating and short lived plant to replicate this as the lifeforms present may not last long enough to wait 6mths for a leaf to die and fall off. 
I think for an ecosphere to work you may have to stick substrate and a plant in there and see what appears. Even then a form of alage would probably work better. 
Just my 2p
Regards
Ollie


> Your description of entropy unfolding in an ecosphere cut off from all external inputs and eventually running out of energy would be correct. However, the moment we put an ecosphere on a windowsill it would receive a substantial input of energy daily in the form of light, and the plants and algae would be transforming that into other forms of energy which continually replenish the system. Similarly, think of the earth as just a big planet sized jar, which keeps water and gases in, but lets light and heat both in and out. And so long as the sun doesn't burn out, both will continue to receive the necessary energy input to fuel life.


http://en.wikipedia.org/wiki/Isolated_system
http://en.wikipedia.org/wiki/Closed_system
The Ecosphere would be a closed sysem not an isolated system


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## a1Matt

Mxx said:
			
		

> But I'm pretty sure I can get algae, bacteria, and perhaps some invertebrates to successfully live for a decent while in a jar, and maybe even some java moss while I'm at it. If there are specific parameters that you believe would become problematic in time then I'm happy to discuss those.



I have done a lot of experimenting with open topped containers (never felt an urge to seal them up) over the last couple of years. 

The most extreme I have done is, an ikea vase with:3 dwarf shrimp, 1 litre of water, a piece of frogbit, and a clump of moss.
The shrimp lived about 1 year in the vase.  I suspected they died of old age as they were already adults when they went in.  
The moss slowly dwindled, the shrimp shrank in size after each molt, they started off healthy adult shrimp, and died looking like lethargic colourless juveniles.  

I felt cruel doing it, but wanted to see how far things could be pushed.  Once the shrimp started shrinking I had to put the vase out of direct sight to allay my guilt.  I do not know what sealing the vase would do, I guess I would expect similar results, as long as you choose critters that would not die of asphyxiation first.


On most other occasions, a productive balance has been sought and achieved. 

eg. Algae coated moss and a couple of ramshorns in a 5l tub, hide tub behind curtain, wait 3 months, clean moss and several more ramshorns out.  Snails can be swapped for shrimp, but lots of floating plants are needed to keep the water quality up. Do not add any substrate or hardscape or they will forage their instead.

eg. Keeping a rare moss alive with zero maintenance for a length of time, by adding water, and some daphnia and putting it in a heavily shaded spot.  Do add substrate\hardscape to provide more bacteria\biofilm.

and so on.

Experimenting with basic combos of shrimp\snails\moss\plants\wood\water\placement (amount of light)\inputs (amount of plant\animal food\light)\outputs (taking things out as they breed\grow) has taught me a lot about balancing out 'low maintenance no tech' systems.

I could keep going on, but am aware I am going off on a tangent so will stop there


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## OllieNZ

> I could keep going on, but am aware I am going off on a tangent so will stop there


Please do. Im really interested In what you've tried and how it worked out. If you feel it will throw the thread off track then please start a new one if you've got the time  . 
My wife would kill me if I left a load of experiments like that around the house not to mention what the kids would do if they found them   so I've got no chance of doing any myself. Im getting quite interested in the idea of a self sustaining tank and any experiences no matter how small can help the rest of us understand the system better.

Regards
Ollie


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## Mxx

Hi Matt, thanks for the input. Were your vessels receiving direct sunlight? I'd perhaps prefer to put mine in a north facing window to avoid direct light and so to not cook the thing, but almost all my windows face east/west. I wasn't sure quite how much light would be best though and maybe some direct sun would be beneficial. They're getting some sun right now 

With my 5 litre vessels I've put flourite substrate into two, flourite capped soil in one, and left the bottom of the other bare for the moment. I'm guessing the capped soil vessel would have sufficient nutrients to keep it going for quite a long time. Only the two flourite ones are going right now with a fair bit of moss in each. One is developing some green algae and the other has none. I'm particularly wondering which will fair better, the soil vessel which has a store of nutrients, or the bare vessel which has albeit quite a decent amount of java moss. 

With these I mostly just want to try and work out the kinks and how exactly I want to do that before I try it with a larger 8-13 gallon bowl/sphere, which might be large enough to appropriately feed and support dwarf shrimp if it contains sufficient nutrients at the outset. I'd certainly be happy to therefore hear your recommendations.

Wait a sec, this isn't my thread, but I'm afraid I may have been hijacking it... I suppose this is still somewhat relative to the original discussion though.


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## Brenmuk

If you are familiar with the idea of a pyramid of biomass it gives an insight into why long term small sealed jars are only able to support small numbers of animal life and probably only small microscopic animal life. The sealed jars would need to be of certain minimum sizes to support animals such as shrimp and snails long term and even larger to support fish - I think the idea is summed up nicely by OllieNZ idea of the elephant in the Eden project dome..   


I'm thinking aswell although I'm not sure about my facts but would Nitrogen eventually become limiting?  Nitrogen compounds would eventually end up as N2 gas. Fixing N2 requires specialist plants and bacteria (and requires alot of energy).  I would expect long term in a 1 lt jar starting with mosses, plants, shrimp and snails etc, that you would end up with just a few forms of algae including quite a bit of blue green algae (that can fix N2) and various bacterial films. I don't think long term there would be enough N to support higher plants.

Adding a soil layer with rooted plants could sustain a system a lot longer as it would provide a large reservoir of nutrients and a larger surface area for bacteria to colonise but i think the same problems still apply.

If you are interested in this kind of thing you might also be interested in large scale experiments like Biosphere2. 
There are also aspects of ecological redundancy ie the theory that larger more diverse ecosystems are more stable - something that a jar on a windowsill would suffer from is a lack of ecological redundancy see 
http://en.wikipedia.org/wiki/Ecosystem_services


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## Mxx

I appreciate that the 'eco-vessels' would need a proportional flora density to support fauna. As invertebrates seem to have a lower metabolism compared to say fish, I thought a small few might nevertheless be well fed in a reasonable sized vessel given enough nutrients to start with. 

I was also wondering whether shrimp might be better off in a vessel with plants such as moss, or with algae alone. It seems they can eat decaying but not live leaves of plants, and I was worried that if there isn't sufficient growth/decay of the moss/plants then they might be hungry, while the plants might suppress algae growth. So I could do a vessel with just algae and a shrimp or two to see if that'd work better. But I might need to leave in a magnetic algae scraper if that's the case, and if I didn't want snails competing with shrimp while they're keeping the vessel surface clean. 

I'd looked into the nitrogen issue recently as well. Agreed that blue green bacteria would perhaps do that, but that doesn't sound ideal of course. Azolla caroliniana is the nitrogen fixing floating plant I was thinking of using. There are six other species but that one seems to be the one most commonly available, with plenty of it cheap on Ebay. And with some Azolla contained and subsisting ,then that should complete the nitrogen cycle and enable it to continue in perpetuity? 

I'd always been fascinated by The Biosphere2 project, though something of that complexity is certainly a tricky thing to achieve a balance with.


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## a1Matt

Mxx said:
			
		

> Hi Matt, thanks for the input. Were your vessels receiving direct sunlight?



I've tried with all sorts of light.
Direct sunlight in summer meant you had to be a bit more savvy when balancing the system so as not to get algae.
At this time of year it is not so much of an issue though.
On the whole I put them in shaded spots, purely for aesthetics (I want them out of the way, I look like a nutter with pots everywhere!)




			
				Brenmuk said:
			
		

> something that a jar on a windowsill would suffer from is a lack of ecological redundancy see
> http://en.wikipedia.org/wiki/Ecosystem_services



I found this.
We all know that substrate contains bacteria, and hardscape can support biofilm, but in such small (<5l) unfiltered systems, these can be a make or break difference to health\success.


Shrimps do better with moss than without.
They do even better with moss and algae.
They prefer hair algae.

Snails will hoover up the slimy algae that grows in sheets over surfaces (I forget the proper term for it).  I find without snails after some time (months) you can not look through the glass.  Moss has a very low fert requirement so is my plant of choice.  Some mosses have a lower requirement than others (I'd avoid Fissidens and liverworts).  

Daphnia are good to stop green water developing.

My moss holding pots often have a couple of daphnia, one snail (added when absolutely tiny to avoid the possibility of breeding, so that when i use the moss elsewhere I can remove the single snail and be confident it is snail free), and if it is going to be there for some time, a single shrimp and some amazon frogbit. I can then feed the shrimp a pellet a week and his poop is moss fert, and the frogbit sufficient filtration.  (Or you can flip it around, feed the plants, and let the critters feed on them.)

There is a key difference with my setups, they are not sealed.  If I was doing a sealed one, I would probably add the biggest wedge of moss I could get my hands on and stuff it full of it.  I would make sure the moss had as many different algae on it as possible. I would add no more than one of snail and shrimp, as if they breed they will use up all the food. and then add a mix of different tiny things (daphnia, cyclops, etc). Some substrate, some hardscape - both from an established tank so that they bring something to the party.


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## Mxx

This initial thread was a bit old anyway, with the owner moving to a new journal. So I think I'll be a squatter here with this discussion unless told to bugger off! 

I actually tried such a one gallon eco-vessel for the first time in my junior high science class, but I didn't then have access to a decent variety of flora and fauna to seed it with after my hunt for Gammarus shrimp came up empty handed. And after unfortunately getting cooked pretty thoroughly on quite an exposed sunny window sill it of course became an algal mess devoid of fauna.

And I meant to try it again this time at the start of summer, but being busy didn't get around to it until just now. I'm picking up a reptile heating strip probably tomorrow which should hopefully keep things at a decent temperature through the winter in my not necessarily heated summerhouse/home office. And come to think of it, I could build a shelf there on either the south facing window, or for the north facing window to get indirect sunlight once the leaves fall off the trees. Right now they're on my desk receiving eastern light, but I'm not at all sure which aspect would be preferable. A bit of algae is okay, but I don't want too much. And I think I'll stick a small nerite snail in each to try and keep the vessel's surface manageable. At least for these eco-vessels to be hidden away in my office they hopefully won't make me look too much the part of the nutter I am...

So I'll aim for both moss and algae in each I guess. I realize that certainly in the absence of current, any substrate will tend to host denitrifying bacteria, thus producing nitrogen gas. Would I perhaps be better off trying to have the moss and algae convert the ammonia produced directly and not have a substrate, in case that minimizes the production of nitrogen gas? I'm going to try the Azolla in at least some of the vessels, but am concerned it will completely smother the surface quite quickly. 

I could however intervene if need be. The lids on the vessels would be mostly to prevent evaporation and any need for ever topping off, but if shrimp or snails overpopulated then I could always take the extras out of course. A major issue of course is what amount of fauna is necessary to provide sufficient CO2 for the flora. I have no idea whether one shrimp and snail plus the assorted microfauna would be enough to sustain a huge clump of java moss. That's not necessarily a problem though, as that would result in some of the moss fading away until the right balance is achieved. Too variable of light amounts from day to day could make that a little tricky though. And perhaps a small fauna population will result in decently high CO2 levels and therefore more rapid moss growth than would otherwise be possible. Speculation...

Does anyone have a brew of Daphnia/Cyclops they could share a little bottle of though? I've yet to hear back from one friend I know that had a batch going earlier.


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## dw1305

Hi all,
If you really want a semi sealed container, I'd go for a large glass bottle, the best would be an old fashioned green glass carboy that were formerly re-used for bottle gardens. Personally I don't think that you have any chance of succeeding with a sealed system, and even with a semi-sealed system I think it is "the bigger, the better". Even a small opening will allow the exchange of CO2/O2. 

I'd definitely have a thin layer of substrate and I'd be tempted to use the cat litter from this thread <http://www.ukaps.org/forum/viewtopic.php?f=17&t=8572&p=17952>, with a minimal amount of leaf mould added. I think you are right _Azolla_ will be much too vigorous, and as Cyanobacteria and Actinomycetes are free living, as well as being symbionts, I don't think you will need it. I can't think of an alternative "floater" with a slow enough growth rate.

I would stick to just moss as your submerged flora, this allows you to use low light levels, I think you will get Ostracods, Rotifers etc from the moss. I'm willing to donate some moss to the experiment. 

I'd try a fern as an emergent, Java Fern,  _Trichomanes_ spp. and _Bolbitis heteroclita_ all do well in bottle gardens. Another option would be an Aroid like _Anubias_.

I'm not sure that a Nerite is a suitable Snail for a small water volume, although I can't think of a suitable snail that won't proliferate. _Asellus_ might be better than a Decapod shrimp like RCS as well, but _Gammarus_ spp. are a non-starter due to their high oxygen demand.

cheers Darrel


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## Mxx

I'd never seen carboys before, despite searching Ebay extensively for large glass containers. It seems they're between 5 and 15 gallons. I saw a number of new ones online for about £30 for a 6 gallon container, and I'm not sure how many gallons the vintage style ones hold.  Thanks for the tip. 

I posted earlier that this was the container I was eventually thinking of using, http://www.ebay.com/itm/18-GLOBES-HALLO ... 2296wt_952, and those at least don't appear to have much distortion. 

My current 5L trial containers have lids, but they're not what I'd call waterproof. If they were then I'd prefer to flip them over. I'd thought of trying to glue them but am not yet sure of any glues that would work which I'd be happy putting on the lid of a container containing living organisms. Though I suppose I wouldn't want to flip my MTS vessel over...

I might try the Azolla, but it might come back out if it takes over excessively. And I was going to get some Java Ferns, so doing them as emergent might be a good idea. Not that I'm worried about these necessarily being pretty either. 

You'd be willing to send me some microfauna? That'd be great if so!


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## Mxx

Update, picked up some Azolla yesterday, which I got for free at World of Water where it was growing invasively in their outdoor troughs of pond plants. And it came with quite a load of Daphnia and other fast little guys, so it seems I don't need any seed stock after all, but thanks for the offer!


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