Self-Sustaining Tank???

[aqua_chem]

In a self sustaining tank? You can't really, that's part of the problem. These nutrients get sequestered away in plants, effectively 'leaving' the system, so you will always eventually run out. It's no different than a planted aquarium in that you need to constantly dose fertilizers. The only think that I can think of is some sort of sustained release system that would last for long periods of time, but I don't know how would be able to supply all the minerals you need, eg iron. Maybe a higher end planted tank substrate?


For magnesium specifically.... maybe dolomite? Would also add base, but also calcium.

 

[Flear]

with the nutrient thing going round & round (the problem that plants use nutrients and don't release them)

i would prefer to have fish that eat the plants, then those nutrients can be reused in the system

 

[GodFan]

I have never run into a fish that actually eats plants. Especially not a small one. If you have algae then the flagfish apparantly eat that. Ottos would eat that too. Maybe a type of snail that eats live plants woukd be better. My plants all grow slow so I dont want them eaten.
I didnt want to go the green water route for aesthetic reasons but you could. Freshwater clams could be a nice additikn then. They filter the water column and would possibly add larva to the column for small fish to eat.
It sounds like you need to look into a small snail species to eat the plants. Then a population of assassin snails to eat the other snails. Problem is you will never be able to balance this because assassin snails would overrun your tank.

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[T1KARMANN]

What if you don't have any plants

 

[Flear]

if you don't have plants, live rock or a DSB to process nitrates.

flagfish love algae
they nibble on the roots of duckweed

i want to get watermeal and see if they eat that

i've heard suggested anacharis lots, i've gotta get that

i want to try things like parots feathers (only example i can remember off the top of my head) as it's leaves are thin, ... any plants with similar thin leaves in the hope that the flagfish will munch on them

but ya, algae, flagfish is the smallest fish i've heard of otto is known for eating algae, but it's appearently kinda particular about it.

much is mentioned about "algae eater", ... but you need to look farther as when you have a particular type of algae, you go get the recommended algae eater, and find out afterwords "yes it eats algae, but not the kind you eat" the siamese algae eater is recommended next to the flordia flagfish for it's algae eating capability, ... and i think the siamese algae eater will touch bba that the flagfish doesn't seem to care about unfortunatly

snails, snails that touch algae, nerite snails come highly recommended, for the most part snails aren't mentioned much for algae control (except for saltwater)

snails do get blamed for eating plants - actually look into potassium deficiency first, or any other nutrient deficiency before blaming your snails. for the most part if snails are eating your plants, they're already beyond done. snails are more into dead stuff.

larger fish are better known for eating plants, ... goldfish is the best known one, ... there's actually only a few things that goldfish won't touch.

 

[Flear]

T1karmann, ... if you don't have plants for what ??

 

[GodFan]

If you dont have plants a seof sustaining tank may not be possible. Live rocks and DSB may work for trates but will allow other nutrients to accumalate.
Crayfish will eat plants. Get you a self cloning crayfish. He will eat the plants and as he reproduces the babies can be food for some fish! Lol I dont know if they will leave any plants though...

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[aqua_chem]

That really more of a salt water methodology. I've never heard of a DSB working for denitrification in a freshwater tank, and liverock is completely a SW thing.

 

[GodFan]

That really more of a salt water methodology. I've never heard of a DSB working for denitrification in a freshwater tank, and liverock is completely a SW thing.

From what i have read DBS works for both. And live rock can exist in freshwate4 we just dont generally call it that

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[Flear]

What I'm trying to say is that an aquarium simulating an ecosystem is a definite possibility, if somewhat difficult to execute. A natural aquarium with a 'self contained' ecosystem is about as unnatural as you can get.

what do you mean ?
what are you saying the difference is ?

 

[Flear]

yes, DSB is any substrate of sufficient depth to support anoxic areas

live rock ... either from coral rock or from fine pored lava rock will work

using coral/aragonite will disolve in low pH setups (usually freshwater)

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for a DSB, the hard part is plants, ... plants will add oxygen to the substrate, turning your DSB into a literal definition, instead of posing any functional denitrification (or anything else done in the anoxic areas)

 

[Wy Renegade]

i'm reminded as i sit here (i forget this too often - because i'm using an air bubbler)
i'm not going to rule out the need for emersed plants,

CO2, a gas, ... gassed off, is no longer available to plants, ... removing carbon from the system

Ammonia, a gass, ... similar to CO2

there's ways around these (both)

azolla has a symbiotic cyanobacteria that can reintroduce nitrogen into forms the plants can use

emersed plants can get CO2 from the air and in turn move this into the tank

Any cyanobacteria will introduce nitrogen back into the system.

As I rule, I'm extremely critical of this concept. It's much more complicated than people take it to be, and I've only seen it executed well a few times.

Agreed

yes, DSB is any substrate of sufficient depth to support anoxic areas

live rock ... either from coral rock or from fine pored lava rock will work

using coral/aragonite will disolve in low pH setups (usually freshwater)

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for a DSB, the hard part is plants, ... plants will add oxygen to the substrate, turning your DSB into a literal definition, instead of posing any functional denitrification (or anything else done in the anoxic areas)

Also agree; nitrate releasing anaerobic bacteria are present in both fresh and saltwater systems - the principle is the same.

As for a small plant that may work for the flagfish to consume, have you looked into thread leaf java fern (not Needle leaf, Thread leaf).

You also may want to look into scuds. It is my understanding that once a population is established, they are pretty good at defoliating plants as well as consuming algae. In addition they provide food for fish - the problem appears to be maintaining the population over the long term.

 

[Flear]

i've heard of amphipods, i don't think i included a size range in my notes ;( have for other zooplankton

java fern (any type) is ... considered among the plants that nothing will touch unless extremely desperate, it's believed to have a bad taste for the fish and is so left alone

currently trying to solve an issue with DSBs and plant roots, ... i might have to skip rooted plants, may be easier to switch to entirely algae, ... but that doesn't provide much for providing blocks to line-of-sight for flagfish happyness and tends to ensure any zooplankton is always out in the open to be seen and eaten, instead of providing an ease of places to hide (because they're behind a leaf somewhere)

 

[Wy Renegade]

amphipods are generally small < 1/4 inch, but vary depending on species.

What about Riccia fluitans or hornwort? Both are floating plants and both have tiny "leaves" capable of not only being eaten, but also for sustain mulm and allowing places for microfauan to survive. Both I believe, but the hornwort for sure absorbs ammonia directly. The only issue I've seen/heard with both plants, is that they will fill/cover the entire surface area of the tank.

 

[Flear]

Riccia is frustrating
the fish aren't eating it :/
it's extremly brittle, trying to pull it out it breaks off, i've got bits and clumps all over in the tank
many people complain about duckweed, it's so much nicer.

although the largest floating clump of riccia i have i am trying to get java fern to grow on, ... would be interesting to have a floating island with something emersed growing out of it otherwise i hate the stuff

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i was initially considering azolla for it's symbiotic relationship with cyanobacteria
then finding out "Anabaena azollae" (the cyanobacteria) produces a neurotoxin.
-so not doing that ;(

hornwort as you suggested, also has a symbiotic relationship with a different kind of cyano. (Nostoc) so will look into that
if so, i'm definitly interested

as the nitrogen cycle includes ammonia, i am certain over any extended period of time this will be a nutrient that will be lost and in turn create a deficiency

... i may be looking at the wrong kind of hornwort as i look for "hornwort" farther on google

 

[Flear]

Ceratophyllum demersum is one i have had recommended, ... and plants similar shapes i am going to go with trial and error to find out what the flagfish will eat.

Edit:
reading farther on this, it also resorts to chemical warfare against phytoplankton, ... :/ not good, not good at all

 

[T1KARMANN]

Well I don't have plants and don't do anything so it is possible

 

[Flear]

self-sustaining (or at least without water changes) without plants ...

1) expect a ton of algae

either a deep sand bed, or live rock

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parrot fish ... not that it's part of their diet, but don't they munch on coral at times ?

for coral, ... i would recommend avoiding the DSB, going live rock and bare bottom tank

coral is really iffy about the idea of considering self-sustaining, ... there is no way i could imagine doing it as the coral itself will grow and need mineral suppliments.

my familiarity with reef tanks and nutrient levels, ... high nutrient levels upset the algae/coral relationship, ... one dies, then the other

without coral, or possibly with soft coral only it's an idea

 

[Wy Renegade]

What about anacharis or elodea? It supports a cyanobacteria population.

 

[Flear]

Elodea is a new one
i have had anacharis recommended lots