What to put in a four gallon aquarium?

I have a four to five gallon fish tank that I’m turning into a nature aquarium!

There are rocks and pebbles at the bottom and a stick or two. So far the only living thing is some Common Duckweed and maybe some algee. If more algee grows than I would like to add some tadpoles (and release them once they grow up).

What should I add next? I love both plants and insects! Would prefer not to have to give them a lot of work or buy anything. And it would be nice if they are native to Idaho so if the population gets to big than I can dump some into a local pond.

It is near a window where it gets medium light, but not direct sunlight. The temperature should typically range between 60-70 F*, though it might sometimes get down to the 50s when we’re on vacation. I have a screen that can go over the top.

Looking for ideas and aquarium-keeping tips!

Badis and Dario my favorite things to go in smaller tanks. Tons of personality, behavior not unlike cichlids, most species are found in a wide range of habitats. The only real caveat is that they’ll pretty much only accept live or frozen foods, but they’re absolute pigs and VERY readily accept food such as frozen bloodworms for badis, and cyclops/frozen baby brine for smaller dario species. Currently I own Badis badis and Badis ruber myself and would like to get Badis kyar or Dario sp. "Black Tiger in the future

Betta fish are great, and tera / crayfish work

As you specifically ask for local fauna and flora, maybe this topic might be vey interesting for you?

I don’t have a good recommendation here, but I would caution against releasing animals kept in captivity into ponds, especially if the aquarium has organisms from multiple sources.

For instance in the case of amphibians, transfer of organisms between ponds can also transfer bacterial and viral diseases which have devastated some amphibian populations, as well as parasites. Scientists working with amphibians generally disinfect all equipment and field gear with bleach when moving between water sources. Organisms in captivity can get new pathogens from foods, etc.


Not really
Most small characin species are a bit too active for me to comfortably put them in a standard 5g, 10g is usually good, though.
Bettas however, are an ENTIRE can of worms. Long story short: they are insanely unhealthy, insanely line bred/inbred, often die of a whole number of organ failure or tumors or etc even when given good conditions, no sort of “good breeders” can help with these, its a problem with domestic bettas in their entirety. It just generally doesnt sit right with me to knowingly buy and support further breeding of such messed up animals. However, a small group of Trichopsis (they’re social, but not shoalers, and do best in groups of 5-6+) and some wild Betta species (splendens complex and coccina are among the easiest to find) are suitable anabantoids for a 5g.
As for Crayfish: Cambarellus species? Yeah, they’re quite small and full of personality, great little guys for small tanks.


Setting up a plant tank is one thing. However, maintaining its appearance and condition at the appropriate level for a long time is a completely different matter. To achieve your goal, you need to regularly prune the plants, change the water and have a well-balanced fertilization, as well as the right level of lighting and CO2. As the plants get older, you may even have to replace some of them with others, as they will not look like you originally imagined.


You know why Bettas can survive in those tiny glass globes? They are obligate air-breathers, meaning that they have to surface for air, just like amphibians. Most fish in those tiny Betta globes would die on day one from suffocation after they used up all the dissolved oxygen.

I wouldn’t recommend dumping them into a different pond than the one they came out of. Apart from the pathogens that @cthawley mentioned, there is also the mixing of local gene pools.

I would also caution you to understand if there are regulations about collecting in Idaho. Fishes and herps are often protected to a higher level than invertebrates.

Dissolved oxygen really isnt an issue in a 5g lol, the species of the smaller Betta species complexes are just small fish that dont move much so they do fine long term in a smaller footprint
Betta sp. and other Anabantoids are also not obligate air breathers, the only fish that are, to my knowledge, are Arapaima. Having the ability to breath air is just, a fairly common adaptation to living in slow moving, low oxygen freshwater environments

@cthawley and @jasonhernandez74 I did not know transferring organisms between ponds could cause problems! In that case, I’ll only take and release from one pond. Thanks so much for the heads up!

I’m not looking for pretty, just a learning experience. I will put in effort to maintain the tank to the benefit of the plants and creatures inside! Thank you!

You can try lots of plants, and some smaller animals. Damselfly nymphs, water beetles, bloodworm, tadpoles. Even smaller fish like the US Gambusia!

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I did find some tadpoles, and love just sitting there and watching them swim and eat! Thanks for the suggestions, I’ll be on the lookout for those creatures. I’m working on IDing more water plants at the pond to bring into the tank.

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