Tank is definitely NOT cycled after only a single dose of Ammonia. Doesn't matter if it was seeded or not it will not be done that quick.
Follow the fish less cycling process. It will likely take several weeks even if you have seeded the tank. Yesterday I wrote up a simplified set of instructions on how to fishless cycle. You might find it useful
So the main sticky for Fishless cycling is great but it suffers a little from information overload and that makes it hard for some to follow the instructions. I thought I would have a go at a "condensed" version. This is in no way meant to replace the original instructions but just act as a...
www.fishforums.net
I've dosed ammonia 3 times now. I guess my original post didn't make that very clear. I'm going to test today to see if the 1 ppm of ammonia I added yesterday is gone yet. My guess is that it is gone. I'm going to dose 2ppm tonight and check again tomorrow night. I know its a pretty fast cycle but if these tests are good, the tank is cycled.
If they are collected from freshwater areas, than go ahead. But size doesn’t matter for tank size. Compreciseps Dwarf Pike Cichlids grows to just under 6 inches, yet the minimum footprint is a 55g. Aggression can add on gallons. I do not suggest bumblebee gobies. Call the aquaria store and ask them if you want proof.
I think a Compressiceps pair/harem are fine in a 40 gal breeder, maybe even a 30 gal breeder? Anyway, I doubt my LFS would dissuade me from getting bumblebee gobies.
"I'm worried about keeping Corydoras in a tank without a cover because I think they're more likely to jump than some species."
I have never heard of a single instance in which corys have jumped from a tank.
Moot subject, this tank is too small for them, anyway
As Myraan and Byron already mentioned, Corydoras are air gulpers. They often dart to the surface with gusty to take a gulp. They can absolutely leave the tank this way.
Putting aside for the moment that your tiny tank is probably un-cycled, as evidenced by your readings of both ammonia AND nitrite, the next important info that you don't appear to have considered at all, is your water's pH and hardness. These are the most important factors to consider when looking at fish, as any fish you choose MUST be able to thrive, (not just survive), in that water.
The second most important factor is tank space, as already suggested, by previous respondents.
You do not have the space for any corydoras. You might be able to accommodate Pygmy Corydoras, but not in the numbers required to keep them happy.
Of all your own suggestions, I see only the chili rasbora being a realistic possibility.
All that said, I'm curious as to your other sources of info, especially when they have led you to believe that corys and chili rasbora are serious jumpers.
My understanding is that corys are air gulpers and liable to jump when they take a gulp, especially since dwarf corys swim higher in the water column than most corys (at least Corydoras pygmaeus does). They won't fit in the tank anyway. I guess I just assumed Chili Rasboras are more likely to jump than, say, Pea Puffers or Dario dario because they're cyprinds (high activity, mid to upper water column dwellers). I'm not really that interested in keeping Chili Rasboras anyway.
The tank processed 1ppm of ammonia and 1ppm of nitrite in 24 hrs. I'm learning this might not be enough, but the tank is really close. I'm going to does 2 ppm tonight and check again tomorrow.
IMO the importance of pH and hardness are wildly overblown in most cases, especially pH. Hardness matters a little more especially if the hardness is an extreme value. A lot of aquarium fish are either captive-bred, in which case they are often comfortable in a wider range of water conditions than their wild counterparts and this is rarely considered. Wild fish are often tolerant of a wider range of water conditions than is often suggested online (see this great article (
https://www.seriouslyfish.com/whaddaya-mean-too-hot/)). Of course this isn't always true and some species of fish are really particular.
In general, people often take water value on online websites as absolutes, when they should really be taken with a grain of salt. Consider the SeriouslyFish entry for
Brachygobius xanthomelas because that's already been brought up. The habitat is described as blackwater peat swamp, negligible hardness and very acid water. The suggested water conditions are pH of 7.0-8.5 and hardness of 143-357 ppm. Clearly this is wrong. In fact, if you look at all the Brachygobius sp. pages you'll see that they're mostly identical copies of eachother. Whoever wrote the Brachygobius xanthomelas page, copy and pasted information from other Brachygobius sp. pages and failed to properly edit the whole thing. If you just read the water conditions section you would get an entirely incorrect idea of the ideal water parameters for this fish.
There are reports of Corydoras leaping out of the tank during total darkness, so it does happen. Loaches are even more likely to do this. Point is, being "substrate" fish doesn't mean they won't/can't. I would never keep these fish in open top tanks unless there is a lot of airspace.
As for stocking, what are the water parameters? These are GH (general or total hardness) and pH primarily (KH and temperature are the others) and with a very small tank the fish will likely be nano and many of these are wild caught so parameters matter even more.
Another caution on the soil...if by this you mean some type of actual soil, be aware that the organics in the soil will break down slowly, and that means lots of ammonia (as well as CO2) for usually several months, depending upon the soil. Most soil substrate aquarists are now recommending a dry start and no fish to six months so this all settles down.
pH is 6.8-7.0, GH is 4 deg, KH is 2 deg.
I have aquasoil (UNS controsoil to be specific). It doesn't take quite as long to break in as dirt.
