A community of REALLY tiny fish - are these all compatible?

[✨Eurobeat✨]

I've been thinking it'd be fun to get a community tank, but only keep really really tiny species in it. Some species on the list are endlers, chili rasboras, pygmy cories, and otos(I really like these species because they're like tiny versions of other fish).

I'm wondering if I could also keep a group of sparkling gourami and/or a single orange australe killifish(Which isn't thaaaaat small so doesn't quite fit the theme as much, but I like them so I don't care).

A couple concerns is if the 2 would have aggression towards each other(Inwhichcase I'd just get one), aggression towards other tank mates, or if the killifish would try and eat anyone since killis I think have kinda big mouths. If chili rasboras would be to small and get eaten, I could also get some slightly larger but still small schoolers like ember tetras, neons, or green neons if they'd do ok.

 

[ClownLurch]

Microdevario Kubotai.
Though I don’t know your water parameters. If hardwater then Heterandria Formosa.

 

[PlasticGalaxy]

What size were you hoping for the tank to be? Keep in mind that the compatibility for species relies not only on the temperament of each fish, but water parameters as well.

As far as friendliness goes, the four species listed at the top of your post are generally quite peaceful and would theoretically get along well together. Keep in mind is that rasboras, pygmy corys and otos prefer softer water, whereas endlers prefer harder water. As well as this, there is a possibility of competition over food between the corys and otos since they're both bottom feeders. Just make sure to feed them well.

One thing I noticed with my gourami (pearl) when I had them was that they would occasionally lunge at my corys to threaten them, but rarely took any nips at them. All the same, this is enough to stress out smaller fish so I would watch out for that. Though with a bigger tank, this may not happen.

Unfortunately I don't have any knowledge or advice on killifish, so I can't offer anything there. Other than that, it depends mainly on the tank.

 

[✨Eurobeat✨]

What size were you hoping for the tank to be? Keep in mind that the compatibility for species relies not only on the temperament of each fish, but water parameters as well.

As far as friendliness goes, the four species listed at the top of your post are generally quite peaceful and would theoretically get along well together. Keep in mind is that rasboras, pygmy corys and otos prefer softer water, whereas endlers prefer harder water. As well as this, there is a possibility of competition over food between the corys and otos since they're both bottom feeders. Just make sure to feed them well.

One thing I noticed with my gourami (pearl) when I had them was that they would occasionally lunge at my corys to threaten them, but rarely took any nips at them. All the same, this is enough to stress out smaller fish so I would watch out for that. Though with a bigger tank, this may not happen.

Unfortunately I don't have any knowledge or advice on killifish, so I can't offer anything there. Other than that, it depends mainly on the tank.

Tank size I'm not quite sure, and yeah I probably don't need gouramis *and* killis. Also not concerned about the otos and cories competing for food as the otos mainly feed on algae and other plant-y stuff, while cories will primarily scavenge for more meaty stuff.

 

[Bruce Leyland-Jones]

Killifish are sweet, but not long lived.
I currently have a 10 gallon nano with chili rasbora, sparkling gourami and shrimp. No conflict so far, though I suspect my shrimp might not be too successful in the breeding department, thanks to the gourami, which are busy clicking at each other and getting jiggy with it already.

Besides chili rasbora, there's a whole host of tiny rasbora to be aware of. I recently acquired some axelrodi 'rasbora' and these look like small neon tetra, without the red. Obviously, within a decently-sized tank, you can have a reasonable shoal and then they should also school nicely for you.

 

[✨Eurobeat✨]

Killifish are sweet, but not long lived.
I currently have a 10 gallon nano with chili rasbora, sparkling gourami and shrimp. No conflict so far, though I suspect my shrimp might not be too successful in the breeding department, thanks to the gourami, which are busy clicking at each other and getting jiggy with it already.

Besides chili rasbora, there's a whole host of tiny rasbora to be aware of. I recently acquired some axelrodi 'rasbora' and these look like small neon tetra, without the red. Obviously, within a decently-sized tank, you can have a reasonable shoal and then they should also school nicely for you.

Yeah not super worried about the killifish being aggressive, more about it just eating the rasboras because they're tiny and could make a tasty snack. Also could the gourami have conflict with the killi because they're both top dwelling fish?

 

[Bruce Leyland-Jones]

Also could the gourami have conflict with the killi because they're both top dwelling fish?

Sparkling Gourami need a quiet tank in which to sparkle. Given the choice between Sparkling Gourami and Killi, I'd go for the former every time.

 

[Stan510]

You REALLY want peace in a nano fish tank. I can tell you the smaller the fish,the shorter the lifespan if things are good. If they are stressed by a bad tankmates or water quality is not up to par? Nano fish drop fast. Its like you might see one sick Monday evening..Tuesday it's gone. scavenger fish and snails make quick work of them.
Not much is said about nano fish lifespans and the fact they are not cheap..and it gets pricey when you want a group. Its like renting them for a few weeks. I did get well over 2 years from a green line Rasbora before she went under. The other two were about half as long lived.
Then,you have 40pound Pacu fish that can live 50 years in putrid aquarium water. Its why Monster keepers like them. Hardy.

 

[Colin_T]

What are the tank dimensions (length x width x height)?

What is the GH (general hardness), KH (carbonate hardness) and pH of your water supply?
This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

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Killifish aren't normally aggressive. If you want a small killifish, look for the clown killi (Epiplatys annulatis)

Sparkling gouramis won't cause problems to catfish unless the tank is really tiny and you have no plants in it. Even then they don't do much if anything except a bit of chasing.

 

[✨Eurobeat✨]

What are the tank dimensions (length x width x height)?

What is the GH (general hardness), KH (carbonate hardness) and pH of your water supply?
This information can usually be obtained from your water supply company's website or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm, dGH, or something else).

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Killifish aren't normally aggressive. If you want a small killifish, look for the clown killi (Epiplatys annulatis)

Sparkling gouramis won't cause problems to catfish unless the tank is really tiny and you have no plants in it. Even then they don't do much if anything except a bit of chasing.

The tank size it a hypothetical tank that does not exist at the moment, and why on earth would anyone take water to a pet store to test it when you can just buy a test kit? I'm guessing my city is on 2 different water sources as pH and hardness gradually go up and down throughout the year, both being pretty low in the summer and higher in the winter. I usually don't bother chasing water parameters and just try to get fish that will be ok in a wide range as long as it doesn't fluctuate too fast, which is vastly more important than what your ph and hardness actually is, and it doesn't fluctuate fast it fluctuates throughout the year.

Basically I didn't list water parameters and tank size because I can't give you a straightforward answer.

Also I wasn't worried about the gourami harassing the catfish, I was worried about it harassing the killifish because they're both top dwellers so might compete, but I'm thinking I might just skip the gourami, especially since it sounds like they can be a bit finicky to keep.