Is it possible to create a closed loop ecosystem in my tank?

[CaptainBarnicles]

I don't understand the point in this...as a fish keeper I enjoy everything that comes with it including tank maintenance ??‍ you wouldn't get a dog and expect it to walk itself would you?

 

[Colin_T]

you wouldn't get a dog and expect it to walk itself would you?

I have seen dogs walking themself. There was a guy that I used to see out walking with his dog. The dog had a lead on but had the lead's handle in its mouth. It was bloody hillarious. I have seen other dogs doing the same thing.

 

[CaptainBarnicles]

I have seen dogs walking themself. There was a guy that I used to see out walking with his dog. The dog had a lead on but had the lead's handle in its mouth. It was bloody hillarious. I have seen other dogs doing the same thing.

? I stand corrected

 

[EllRog]

? I stand corrected

Only corrected on the analogy. Your point was well made

 

[PheonixKingZ]

I don't understand the point in this...as a fish keeper I enjoy everything that comes with it including tank maintenance ??‍ you wouldn't get a dog and expect it to walk itself would you?

Some aquarists like their “no maintenance tank” because they literally have to do nothing. If fish live, they are happy. If fish die, they just buy new fish.

It’s grotesque, but lots of people do it...

 

[starzfish]

I don't understand the point in this...as a fish keeper I enjoy everything that comes with it including tank maintenance ??‍ you wouldn't get a dog and expect it to walk itself would you?

Just because a bunch of you guys recommend against it, I'm not gonna do it. I'm just gonna get a 5 gal with a betta and maybe a shrimp or 2.

 

[CaptainBarnicles]

Just because a bunch of you guys recommend against it, I'm not gonna do it. I'm just gonna get a 5 gal with a betta and maybe a shrimp or 2.

? awesome... Although the betta might eat the shrimp, so...

 

[starzfish]

lol the shrimp is like half the size of the betta and the LFS said the shrimp won't get eaten.

 

[CaptainBarnicles]

? Don't believe everything your LFS says, rather listen to people here on this forum who have been keeping fish for years and have lots of experience. LFS want your money and will tell you whatever for you to give it to them

 

[Essjay]

What species of shrimp?

I had a betta which killed and attempted to eat red cherry shrimps. I kept finding bits of shrimp on the bottom of the tank.

 

[Slaphppy7]

Fishkeeping IS NOT a "hands off" experience; that's what makes it fun.

Just IMO.

 

[ArmchairAquariest]

Conceptually: yes you can, but even when you get to the level of small fish you need a pretty big and complex tank. There are small closed "ecospheres" you can buy but they don't get beyond dwarf shrimp. The ecosystem is a pyramid and so as the "height" of said pyramid goes up, the "volume" goes up roughly proportional to the cube ("height" being level of organism on the food chain, and "volume" being total number of creatures and organisms of all types needed to maintain stability.") In about 5 to 10 gallons you can do dwarf shrimp and smalls snails like this if you are careful -- I have an unfiltered one running at the moment myself. By the time you are at small fish though you will probably need a very complex ecosystem and like 50 gallons.

As others have said above, nothing is truly maintance free. If nothing else you will probably have to prune some plants, fish out the occasional dead body, and do the occasional water-change. But you can get it to the point where the only thing you are "feeding" is a good light source, and every couple of months some plant fertilizer to compensate for the plants material that has been removed due to pruning, I have done that before. I got a 5 gallon shrimp and snail container, unfiltered, to the point of: no food besides light, water changes every 5 months (but occasional water top-offs in between if the water level is going down due to evaporation), and the tiniest pinch of fertz and calcium once a year.

If you want to do fish in your system then I would remove the dwarf shrimp from the setup I have and switch to amphipods and fish that will eat them. One problem I am not sure how to get around is that daphnia and rotifers are incredibly useful for maintaining water quality in a "closed" (or nearly so) ecosystem -- but fish eat them like popcorn and just wont stop. Even if they aren't hungry fish always seem to have room for "just one more daphnia." So I have never managed to establish and maintain healthy populations of daphnia and rotifers in tanks with fish, but I don't no how to build a closed(ish) system without them -- they do some heavy lifting on eating water-born bacteria, fungus, detritus, etc... and recycling those nutrients to the rest of they system. In theory some clams might be able to do that job instead, but clams are not low maintenance and are hard to put in a small ecosystem as I believe they need some large support critters to properly integrate into an ecosystem (like possibly crayfish among other things, though I don't know enough about closing the ecology around clams to say for certain.)

 

[WhistlingBadger]

You know, I think @starzfish is making a good decision not going with the closed system concept. Some of you made some pretty good, practical arguments against it. But I have to say (speaking as a forum member, not as a moderator--nobody has broken any rules here) that I don't like the "Hey, someone's doing something different; let's immediately start questioning his/her motives and asking what's the point?" way of thinking. Implying that this person is lazy, doesn't care about fish, or is less of a fish keeper is, in my humble opinion, unkind and out of line. There are lots of different ways and lots of different reasons that people keep fish. Your way is not the only way.

I personally can see the appeal of a project like this, as ultimately impractical as it is. I find natural ecosystems fascinating, and that is part of what draws me to fish keeping. To my way of thinking, a closed-system aquarium would be the perfect aquarium, because it would require such perfect balance to achieve, every organism doing its part without me hovering in the wings playing god. It would require a balance so perfect, as some of you have pointed out, that it probably isn't possible to make such a system work, long-term. Still. It's a fascinating idea.

One of my current tanks is the closest I've ever gotten: A five gallon tank with lots of plants, green water (so it isn't very enjoyable to watch), scuds, seed shrimp, pond snails, water fleas, black worms, copepods, and a single blue rasbora who is only in there because I can't see well enough to catch him, but who looks extremely well-fed when I get a glimpse of him. I put in a pinch of food about once or twice a week to keep the black worms happy, but I don't think that's even necessary. Only other inputs are light, heat, a tiny sponge filter just to move the water around, and weekly 10% water changes. I'll probably tear it down soon if the green doesn't clear up, because it isn't much fun to look at...but the green water is, of course, keeping the water fleas and copepods happy, and those keep everybody else happy.

I for one appreciate the OP, both for taking good advice, and for thinking out of the box (or the fish food can) in the first place.

 

[WhistlingBadger]

Starz, if you do decide to go ahead with this idea, I would advise a few principles to follow:
1. Read "ecology and the planted aquarium" by Walstad. Take notes. Then read it again.
2. Biodiversity = stability. The more kinds of plants and inverts you have, the better chance you'll have.
3. For your apex species, do your research. You want a species that is small, probably omnivorous, adaptable, and ok solo or in very small groups. Also check compatibility with your water supply's pH and hardness.
4. Set realistic goals for your system. A completely closed system? No way. Light and water changes, at the very least, will be required. Some sort of circulation and heat might be required too. But a mini-ecosystem where the fish rustle their own grub, and you don't have to feed them? Difficult, but doable.

 

[starzfish]

? Don't believe everything your LFS says, rather listen to people here on this forum who have been keeping fish for years and have lots of experience. LFS want your money and will tell you whatever for you to give it to them

Quite the contrary, when buying my 5 gal tank for my betta, he said I don't need a water heater and recommended me a 2.5 gal tank instead of 5 gal. After doing some research I went with a 5 gal cuz its still large enough and somewhat small enough to fit on my table. Might do some aquaponic later down the road for it tho.

Thanks everyone for your replies!