The Perfect Axolotl Ecosystem

As I get closer and closer to moving my axolotls into their final tank, I can't stop planning how to set it up. I've always been interested in a riparium (aquarium-terrarium hybrid) setup and today I wonder what is preventing a setup with a perfect axolotl ecosystem. That is to say, all waste products are utilized by the next organism in the food chain.


Appropriate food waste from the kitchen would be emptied into a worm farm. This would provide nutrients for worms which would, in turn, be fed to the axolotls. Shouldn't be any problems so far. The axolotls produce ammonia waste which is converted into nitrates by the nitrifying bacteria in the filter. The nitrates are utilized by a mixture of aquatic and terrestrial plants and ultimately converted into gaseous byproducts that are returned to the atmosphere.

In such a system, there would be no need to purchase worms or axolotl food, since the worms are fed with the potato peels etc that you would otherwise through away. Similarly there would be no need for the water to be cleaned, as the plants would absorb all the waste that is toxic to the axolotls.
There are many examples of hydroponic aquariums that are perfectly stable with negligible water changes and since our axolotls eat worms, which we can farm on our own food waste, this system would be fantastically efficient!

Is this possible?

If not, where is the kink in the chain? Which byproduct would not be controlled by the organism that feeds off it?

Just to be clear, this thought does not arise from a desire to reduce maintenance, but a dream of an almost self sustaining ecosystem. I wouldn't plan to eliminate the need for a dedicated filter and water changes. The filter would remain as an efficient source of nitrifying bacteria, while water changes would still be done infrequently (less than monthly?) to remove contaminants that could not be used by the organisms within the ecosystem.

You want to have a worm farm in your axolotl tank ?
You can establish a minimum maintenance tank by having a low stocking density ,filling the tank with plants and using live food rather than pellets. A number of people use this set up and just top the tanks up to replace water lost through evaporation.

xxianxx said:

You want to have a worm farm in your axolotl tank ?
You can establish a minimum maintenance tank by having a low stocking density ,filling the tank with plants and using live food rather than pellets. A number of people use this set up and just top the tanks up to replace water lost through evaporation.

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Haha no the worm farm would of course be outside.
Any ideas on the stocking levels? My intentions were to have 3 axololts in a 180L tank, with a few aquatic plants and lots of terrestrial plants (with roots/substrate sapping water from the tank). Possibly a DIY internal algae scrubber too, hidden behind a 3D background.

Here is a link to the research Bill Wolverton did while at nasa regarding plant filtration of wastes and VOC's volatile organic compounds some very cool research that might shed light on plant choice and methods for implementation. Should be right up your alley. A book on worm farming that I have had for years explains how to do vermiculture indoors using veggie scraps from the house it is called the worm book here is a link. Sorry if the links don't work this is my first time posting a link. The old copy and paste should work though.

http://www.amazon.com/Worm-Book-Complete-Gardening-Composting/dp/0898159946/ref=sr_1_8?s=books&ie=UTF8&qid=1397107240&sr=1-8&keywords=vermiculture

[/B]http://spinoff.nasa.gov/Spinoff2007/ps_3.html

They didn't work

I post links by right clicking where you would usually enter the page, and than pressing "copy shortcut". And then when your ready to post it right click and press "paste". It might be different for different computers and such though.

Many of us have what you describe, except usually not for axolotls but for other caudates.
I have a worm culture, i use no filters, it´s all biological filtration through plants and bacteria and my tanks require so little maintenance it´s ridiculous.
This can definitely work for axolotls too, the only difference is that you need a large tank with a large volume of water, because they are large beasts that produce plenty of waste. I don´t see it working stably in the 10 gallons tanks that many people use for axolotls...

I had a tropical fish tank that ended up stable, more through happy accident than by design, since it got neglected while at my parent's house while I was in grad school. But I had guppies and algae eaters in there and the plants just grew like mad and no one every changed the water or maintained the filter or anything and it just kept going and going and going with occaisional top-ups.

I think this might be harder to do with an axolotl tank because the levels of lighting you would need to get really robust plant growth might stress the axolotls. Then again, if they have plenty of hides, they might be fine.

I think the problem with with sort of setup is that it is relatively easy for everything to fall apart if there is a hiccup in the system. Say the power goes out long enough for the plants to stop growing or even start decomposing - that would throw everything off. I personally would be worried about that sort of thing happening, even if there is a good chance of it working perfectly.

I also keep earthworms in a compost bin in my basement and feed them on food scraps, and use them as the primary food source for my axolotls. Just to take things full-circle, I often use waste water from the axolotls to water my houseplants, which seem to be thriving. If I got enough sun for a garden, I could use it to grow my own veggies, and feed the scraps back to the worms
(I actually do water changes on my tank frequently, but more because I like to siphon out all the poop and keep things looking pretty than because it actually needs it.)

Also, if you do set this up, I'm sure we'd all be interested to hear about it/see pictures

Adogowo said:

Here is a link to the research Bill Wolverton did while at nasa regarding plant filtration of wastes and VOC's volatile organic compounds some very cool research that might shed light on plant choice and methods for implementation. Should be right up your alley. A book on worm farming that I have had for years explains how to do vermiculture indoors using veggie scraps from the house it is called the worm book here is a link. Sorry if the links don't work this is my first time posting a link. The old copy and paste should work though.

The Worm Book: The Complete Guide to Gardening and Composting with Worms: Loren Nancarrow, Janet Hogan Taylor: 9780898159943: Amazon.com: Books

[/B]Plants Clean Air and Water for Indoor Environments

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Very interesting work indeed, although couldn't find much information applicable to a tank.

Azhael said:

Many of us have what you describe, except usually not for axolotls but for other caudates.
I have a worm culture, i use no filters, it´s all biological filtration through plants and bacteria and my tanks require so little maintenance it´s ridiculous.
This can definitely work for axolotls too, the only difference is that you need a large tank with a large volume of water, because they are large beasts that produce plenty of waste. I don´t see it working stably in the 10 gallons tanks that many people use for axolotls...

Click to expand...

I had no idea that a stable cycle could be established in the absence of a filter or powerheads, besides in ponds or XL aquariums. In these systems, what surfaces are utilized for bacterial growth, in place of filter media? I have always assumed that without dedicated media and flow, that the bacteria would need lots of appropriate surfaces to colonise the majority of the aquarium, and that any disturbance to this would mess up the ecosystem? Could you give any kind of estimate of the amount of water, 'media', and plants required to maintain a single axolotl?
As said, I would love to set up an ecosystem in my 55G that could cope with all waste such that axolotl poop becomes merely an aesthetic issue. Moreover, if this is perfectly possible, then I could replace the sand with river rocks that would better hide any muck that can just be left to break down naturally.

kjnorman said:

I had a tropical fish tank that ended up stable, more through happy accident than by design, since it got neglected while at my parent's house while I was in grad school. But I had guppies and algae eaters in there and the plants just grew like mad and no one every changed the water or maintained the filter or anything and it just kept going and going and going with occaisional top-ups.

I think this might be harder to do with an axolotl tank because the levels of lighting you would need to get really robust plant growth might stress the axolotls. Then again, if they have plenty of hides, they might be fine.

I think the problem with with sort of setup is that it is relatively easy for everything to fall apart if there is a hiccup in the system. Say the power goes out long enough for the plants to stop growing or even start decomposing - that would throw everything off. I personally would be worried about that sort of thing happening, even if there is a good chance of it working perfectly.

I also keep earthworms in a compost bin in my basement and feed them on food scraps, and use them as the primary food source for my axolotls. Just to take things full-circle, I often use waste water from the axolotls to water my houseplants, which seem to be thriving. If I got enough sun for a garden, I could use it to grow my own veggies, and feed the scraps back to the worms
(I actually do water changes on my tank frequently, but more because I like to siphon out all the poop and keep things looking pretty than because it actually needs it.)

Click to expand...

Thank you. I had expected this to be much more feasible in highly established mature systems. So in that system the filter was acting more as a powerhead than a dedicated source of nitrification?
The lighting does pose an issue. The tank will be in a North facing room so will receive no direct sunlight, perfect for axolotls but not of course for plants. I had come up with a few options, that I was going to read and ask about on planted tank forums but I'd love to get advice here if possible.

Low Light Plants - Ferns, Mosses etc. Plants that could survive without direct sunlight and in high moisture levels (for the terrestrials). I assume these have a proportionally low metabolism and so would not significantly deal with nitrates. Is this true? Could the ecosystem set up in a 55G tank with no direct light.

High Overhead Lighting - Grow lights would be mounted well above the aquarium so that the light and heat do not affect the axolotls. This would primarily serve terrestrial and surface plants. I would like to minimize the number of purely aquatic plants for aesthetics and to maximise space for the axolotls. I don't see why this wouldn't work but I'd have to find out how much lighting was needed and as you say, susceptible to power cuts.

Algae Scrubber - Potentially in addition to the above, I had the idea of a hollow 3D background that housed an algae scrubber spanning the entire back glass of the tank. This would be driven by a full length air curtain behind the 3D background, and lit by a grow light behind the tank. Would this work? I expected the amounts of algae to easily deal with nitrates but the lighting would be much closer to the tank and so risks heating the water,

Thoughts on the feasibility of each of these options?

I am entering the final months of my degree so will not have time to do this until July. When I do, I hope to make a thread to keep track and get advice on the build as I do it.

You can light the tank as much as you want if its fully planted, the plants block out the light so the axolotls would have plenty of shade. Why do you want to remove the algae ? It will remove the nitrates and wouldn't cause any problems to the axolotl. In a heavily planted tank you probably won't see too much algae anyway as the plants will keep the levels down.

xxianxx said:

You can light the tank as much as you want if its fully planted, the plants block out the light so the axolotls would have plenty of shade. Why do you want to remove the algae ? It will remove the nitrates and wouldn't cause any problems to the axolotl. In a heavily planted tank you probably won't see too much algae anyway as the plants will keep the levels down.

Click to expand...

I'm referring to the filtration method of Algae scrubbing, not the cleaning of the glass. Essentially you provide perfect conditions for algae growth in a dedicated place so that they remove nitrates but don't ruin the aesthetic.

I would have some plastic mesh across the entire back glass, hidden behind a hollow 3D background. An air curtain would provide water flow with water being drawn in throw holes at the bottom of the 3D background and flowing out of holes at the top. And then a single light behind the tank.

DIY Algae Scrubber

The surface for the bacterial biofilm is provided by the plants. Every submerged surface will eventually be colonized by the bacteria. In addition, the plants produce oxygen for the bacteria and they themselves act as biological filtration so in combination you do get a very effective, very stable system. No need for filters and their unwanted heat and currents.

I can´t really give you an stimate of tank size, plant load, etc since i don´t keep axolotls. But i can tell you that you want A LOT of plants...
Like Ian said you don´t have to worry about bright light if the surface is covered with dense mats of plants, the bottom of the tank will be quite dark and axolotl friendly.

Edit: Forgot to mention that the algae scrubber thingy is really unnecessary...If you have plants that reach the surface and have an aereal portion, they will have access to carbon dioxide without the use of aereation and those plants will consume nitrates. I REALLY like Hydrocotile leucocephala because it works perfectly for this, it creates thick dense mats that break the surface, it grows very fast so it is an effective biofilter, doesn´t require strong or special lights and creates a lot of shade. It´s just perfect...

Rodrigo, would you recommend floating plants too? If so, what species?

I don´t currently have any trully floating plants myself but any species that can adapt to caudate tank conditions would be fine. Some people use Pistia, Lemna, Azolla, Limnobium...
It is also possible to use terrestrial plants grown hydroponically with their roots in the water.

http://www.caudata.org/forum/f46-be...filters-substrate/96565-filters-axolotls.html

Check out the link above. I use plants and microbial action to "filter" my water, in addition to water changes. In a larger system, the need for water changes slcould be drastically reduced.

Cole

I'm using something similar - no filter, just natural pond water, lots of living plants, and regular partial water changes. Of course, we've only been doing this for a couple of weeks, so who knows how well it will work in the longer term.
Also, we have been feeding bloodworm pellets rather than live worms. This has not caused problems so far, as Boris the albino axie suctions up every last bloodworm from his feeding corner. We also remove any debris every day or two. (I have been reading about a Norpro glass turkey baster that is apparently excellent for this purpose.)

I'm sure you've already figured it out by now, but I'm building a 60gallon refugium for a 125gallon aquarium and the plan is to have axolotles (of which I currently have none) and then a sump/refugium that will house live feeders such as guppies and ghost shrimp underneath the aquarium. Also the fuge will have plants as well as the main tank. I think my aquarium concept might be a good idea for you. Also I couldn't find anywhere that advised against cO2... Does anyone know of it's okay to have either liquid or gas co2 in an axie tank?

Any form of CO2 will be ultimately dissolved in the water. You're idea sounds okay but you will need to keep restocking your refugium with shrimp and guppies. Ghost shrimp and guppies need temps warmer than what is acceptable for axolotls, especially if you want them breeding. You will still get pregnant guppies but below 70F the female will never give birth. With that being said you could still have plants to act as a waste sponge for your axolotls. If you really want fish to breed then go for white cloud minnows but they are no where near as prolific as guppies.