What would be in your unfiltered aquarium?

[Kirsten]

I wish I could find the post that inspired me. Some clever nerm had set up a beautiful 10g (I think) full of plants and moss for their desk, no heater, no filter, just a good light on a timer and a small school of white cloud minnows. And it was mwah, perfect.

I keep thinking about the challenges of a low-tech, but still low-maintenance tank and how fun it would be to set up, smaller or larger, community or display. How would you set up your ideal low-tech tank?

[FrozenFins]

I have been wanting a tank like this not because its less matnience. But because in the fish wild habitats there are no filters providing oxygen or humans coming in with their gravel vacs doing waterchanges but instead there is plants removing nitrates, and providng oxygen and so much more. And then there is the sun providing evaporation, and then rain to top off the river. 

My low-tech - low matnience tank would consist of...

55 Gallon 

Plants: Big  lush Jungle of  Valsinaria, Amazon Frogbit, Cryp wendetii, dwarf sagiteria 

Fish: Angelfish, Corydoras, Kuhli Loaches, Cardinal Tetras, Smaller sized pleco

it either that or...

10 Gallon

Plants: Moss, Amazon Frogbit, Dwarf Sagiteria, Hornwort

Fish: Breeding Colony of guppies or platys, and cherry shrimp.

Can't decide which one. Probably both.

[Colu]

In an filtered tank you would be best with labyrinth fish such as gourami or betta or corydoras as they can breathe  atmospheric air

[Kirsten]

29 minutes ago, Colu said:

In an filtered tank you would be best with labyrinth fish such as gourami or betta or corydoras as they can breathe  atmospheric air

True! But in that case I'd at least need heaters since gourami are quite more tropical than my home. Hmm.

I've heard that enough plants should theoretically be able to oxygenate the water enough for other fish. But that's a pretty big risk!

[Spewing_nonsense_]

So honestly I'd probably do like a 10 gallon or 20 long and have primarily a whole bunch of slow growers, anubias, crypts, moss, as well as some frogbit on top. Altho I'd probably have one or two faster growers, I'm not entirely sure what tho. Then I'd probably let it grow and get all these zooplankton going and make this huge ecosystem get going, with plenty of snails too. Then after it has a few months for all the different species to get to sizable populations I'd probably add a scarlet badis or two and like 6 kuhli loaches plus some clown killifish.

 

[Spewing_nonsense_]

5 minutes ago, Kirsten said:

True! But in that case I'd at least need heaters since gourami are quite more tropical than my home. Hmm.

I've heard that enough plants should theoretically be able to oxygenate the water enough for other fish. But that's a pretty big risk!

I mean, as long as you dont have like a huge colony of guppies you should be fine, it all depends on the size of your tank, surface area for passive oxygenation, and how many fish you got

[Colu]

Macropodus opercularis   Paradise fish can breathe atmospheric air and can be keeped  in unheated aquarium

Edited January 21, 2021 by Colu

[Daniel]

The majority of my aquariums run without any filters. A couple of my favorites are:

The 1930s aquarium (no lights, no filter, no heater):

My livingroom aquarium has a heater (because of discus) but no filtration:

Both tanks are very low maintenance.

[Kirsten]

Beautiful! Omg. I'm shocked at how beautiful the Discus tank is, despite (any? many?) living plants. Minimalist and majestic!

[Daniel]

1 minute ago, Kirsten said:

Beautiful! Omg. I'm shocked at how beautiful the Discus tank is, despite (any? many?) living plants. Minimalist and majestic!

Some water sprite and some very pretty looking green hair algae. In the previous incarnation I had gone overboard with plants. So after I got bored and changed up the tank I went hardscape only. I was skeptical at first that I would like it, but it turned out it looked okay. You never know until you try..

The overplanted version also had no filter.

[Koi Fish]

1 hour ago, Daniel said:

The majority of my aquariums run without any filters. A couple of my favorites are:

The 1930s aquarium (no lights, no filter, no heater):

My livingroom aquarium has a heater (because of discus) but no filtration:

Both tanks are very low maintenance.

Hi Daniel,

How often do you do water changes on your livingroom tank? I’m thinking of taking out my one sponge filter in my 40 gallon tank. Its a sand substrate moderately planted. Do you worry about nitrates & debris build up with no filter?

cheers
 

[Streetwise]

As Daniel alludes, with enough plants, your inhabitants will be fine. 

I could keep all of my Nano fish, and Neo Shrimp tanks without filters. I like sponge filters for moving water, and collecting things in foam, including beneficial bacteria.

I mostly top-off, and rarely change water. I don't plan on cleaning my sponge filters. They are part of the scavenger buffet.

Edited January 22, 2021 by Streetwise

[Daniel]

45 minutes ago, Koi Fish said:

Hi Daniel,

How often do you do water changes on your livingroom tank? I’m thinking of taking out my one sponge filter in my 40 gallon tank. Its a sand substrate moderately planted. Do you worry about nitrates & debris build up with no filter?

cheers
 

I echo what @Streetwise says above. I don't worry about nitrites and nitrates because the plants will consumes those as soon as they are produced. But, you'll notice that in both tanks I keep the stocking load low. Having a filter allow you to crowd more fish into your aquarium, but with a low stocking level and plants, you will do just fine without one.

If you go without a filter, strongly consider an airstone to help increase oxygen levels and also help circulate the water in the tank.

[JettsPapa]

3 hours ago, Daniel said:

Some water sprite and some very pretty looking green hair algae. In the previous incarnation I had gone overboard with plants. So after I got bored and changed up the tank I went hardscape only. I was skeptical at first that I would like it, but it turned out it looked okay. You never know until you try..

The overplanted version also had no filter.

"Overplanted"?  I'm sorry, but I don't understand what that means.

[shkote]

I have an unheated, unfiltered very low maintenance 5 gallon dirted tank at work with a light on a timer. It has 4 male Endlers. I only do top offs on this one. 

[Koi Fish]

Thanks @Daniel & @Streetwise good information.

[MAC]

I keep a dirted 10 gallon with a carpet of dwarf hair grass that is unfiltered. It has ramshorn snails and malaysian trumpet snails and I use it as an intermediate grow out for baby killifish. 

My dwarf frog tank is also pretty much filter less. It has a sponge filter and airline but only a few bubbles a minute come out. Light stocking and lots of plants seems to work. 

 

 

 

Edited January 22, 2021 by MAC

[Will Billy]

You know, ive thought about this a lot, but havent had a chance to respond to it yet. It would be a low tech tank, but i would still have a small sponge filter for the trifecta of water movement, filtration, and oxygenation. I have often contemplated taking a 20 gallon long, and taking the plunge into a dirt substrate. I think i would do a carpeting plant across the entire bottom. Maybe something like monte carlo, or S repens. Just a field of green, with a few spots broken up with some dark slate rock and some bits of drift wood. Glue some water column plants like java moss to the slate and some anubias to the driftwood. And top it off with some simple floaters like giant duckweed or red root floaters. Keep the stocking simple with bladder snails, some cherry shrimp, pygmy corys, and oto cats for cleaners, and some neons and harlequin rasboras for my pretties, with a dwarf gourami for my centerpiece. I think (and i may be deluding myself here) if i were to properly maintain the soil, and detritus i could  primarily depend on the plants for filtration, with the 1 small sponge filter helping with my bacteria, oxygen / CO2, and water movement. Being honest though im quite nervous to try a dirt substrate tank. 

[HenryC]

I think you would have to have an extreme amount of fast-growing, stem plants. I had a 40 g tank that had choke full of ambulia and hygrophilas, and moderately sttocked. One time my canister filter failed, the tank remained without filter for a little more than a week, just heater and airstone without any problem or any losses. I'd suggest making a giant stem plant wall at the back to soak up excess nutrients if you wanna go unfiltered!

All I did was squirt easy green weekly after a water change, and planted root tabs just once.

That version of my 40g was the most stable one I've had over 2 years. Super low nitrates even after 2+ weeks of no water change, crystal clear water, and near zero algae.


When I rescaped it and removed all the ambulia and hygrophilas, the problems started. High nitrates, and algae started to overrun everything. I learned my lesson. Now I am starting to slowly go back to a stable system with tons of vals and duckweed:



So my tip would be: Plant suyper heavy with a fast growing stem plant that you like! I suggest 3 that I'v'e had extreme success with:
Hygrophila Corymbosa
Ambulia
Elodea (brazilian waterweed)

Edited January 31, 2021 by HenryC

[Koi]

I run most of my tanks unheated but I shared this picture in another post. This is the most barebones kind of setup I have besides the bucket of plants I harvest snails from outside. It runs with just the air stone and light but I don't really need air for this system but since I have an air pump lying around why not use it? 

[H.K.Luterman]

I'd really love a 20 long, stuffed full of fluffy stem plants (I'd like another go at growing cabomba), and a million neo shrimp and snails. I'd just have to convince my hubby that yes, I do need a 7th tank. X3