Nano riverine stocking suggestions

I have a UNS 45S (17.7 x 11 x 7.1 in) which I've 'scaped as a stream with sand, rounded stones, and twigs. I plan on planting the tank with crypts in the Ultum soil (black soil in the photos). It will be unheated and filtered with a Eheim Classic 150 canister filter. The inflow and outflow of the filter will be placed on opposite sides of the tank to facilitate a (hopefully) moderate but consistent manifold. I'll have to play with the filter outflow type to get the desired flow rate. The tank will be uncovered; I know this is risky, I'd like to stock in a way to avoid jumpers. I know there is always some risk of finding a dried up fish on the floor when you have an uncovered tank, but I don't want to stock a fish known for jumping.

The size of this tank is quite unusual. While the tank is small (6 gallons unfilled, probably 4-5 when filled), the footprint is comparable to a larger tank. Combined the overspec'd filter I would think I can push the stocking rules some. However, I'm still having trouble finding fish that work in the tank. It seems most nano fish come from stagnant waters. Here's a list of possible stock I've put together,

Honeycomb (Oil) Catfish (Centromochlus perugiae)
Akysis sp.
Gold Ring Danio (Brachydanio tinwini)
Microdevario kubotai
Vietnamese White Cloud (Tanichthys micagemmae)

I'm inherently worried about the B. tinwini, M. kubotai, and T. micagemmae jumping simply because they are pretty active and not bottom dwellers. Are any of these fish known jumpers? I'm also worried about the C. perugiae as they feed right at the surface in the evening, and they are nocturnal. I like the Akysis sp. a lot, but they also nocturnal and I worried I'll never see them. Does anyone have experience with these catfish? Are they really timid?

Finally, it occurred to me today that a riverine goby might work in the tank. Something like a small Stiphodon species or maybe something else that I haven't heard of (especially something that is sustainably raised/collected unlike Stiphodon). These would be ideal in that they are bottom dwellers, but they're not nocturnal. They can also be quite showy and are pretty interesting IMO. What do you think?

Finally, are there any other riverine fish I should consider that I haven't thought of yet?

Here are some photos of the hardscape,

Look into hillstream loaches
Id do a group of those

Really interesting looking tank and project. What is your water like? Hardness can often lead you in the right direction of what to keep.

if you are worried about jumpers have you considered a glass lid -ADA do some nice clips to rest a piece of glass on and you can get a piece of glass cut to suit. Or you could get one if the big crypts lie crisp

nice find on the oil cat - good info for the hard water gang on this forum. when you mentioned them I assumed soft water but they are documented as being very adaptable all the way up to 20 degrees!

Wills

I thought Hillstream Loaches were a no-no in a tank this small.

Water params are,

GH: ~70 ppm
KH: ~50 ppm
pH: 7.6-7.8

I just realized the Oil cats are out if I keep the tank unheated. It seems these come from relatively warm waters, 24 deg C and up. I actually have a mini heater, and I might add it if I decide I really want the Oil cats.

Because of the tanks diminutive height and current location, I'm planning on viewing this tank top-down most of the time. A lid, even a glass lid, will be an obstruction. I might consider glass or clear plastic that clips to the side of the tank and acts like a 1 - 2 inch fence around the rim of the tank.

Have you seen the Red Sea Jump Guards? Its like a netted frame you construct for your tank. I have one for mine but not set it up yet as I dont have any fish.

Wills

I think if you did species only, the hillstream loaches would be doable

I just found out that Microdevario kubotai and Akysis vespa come from the same areas along the Myanmar and Thailand border, for example the Ataran and Suriya River basins. The kubotai are tiny, 0.75in, and the vespa are pretty diminutive too, <1.5in, I think I could fit small colonies of both in one tank.

Based on some other researching, this area hosts some nice plants too, Cryptocoryne crispatula var. balansae and var. crispatula, C. albida, and Pogostemon helferi.

I believe I could do a strict biotope that would look really nice!

Microdevario kubotai would adore that tank. And they love flow.
Problem is the lidless issue. I wouldnt trust them not to jump

Ive got them in my 20 long. Excellent little fish.

The lid thing is an issue.

The problem is that the whole point of buying this UNS tank, and doing this scape is so I can view it clearly from above. I grew up in the Pacific Northwest and I was originally inspired to get into fishkeeping by local water features. This whole tank is a homage to the (cold) rainforest streams I grew up around. Thus, it's extremely important to the whole concept that I can look down in on the sand and rounded rocks like it's an actual stream.

I do like the Red Sea Jump Guards, and maybe I can remove the lid from time to time to view the tank. As an unusual alternative, I could build a short 'fence' around the rim of the tank that would make it harder for jumpers to clear the tank rim. I'll probably try building the 'fence'. If that fails, I'll either go lidless or, use the red sea jump guard.

Also, Cryptocoryne crispatula "balansae" grow so tall they will form significant surface cover in the tank if choose to include them in the scape.

Could even do a custom cut of clear glass so you can still view through it.

But bear in mind kubotais need a heater too, depending what your room temperatures are.

NCaquatics said:

Could even do a custom cut of clear glass so you can still view through it.

But bear in mind kubotais need a heater too, depending what your room temperatures are.

Click to expand...

I don't think I need to heat the tank. M. kubotai come from exactly the same river basins as A. vespa. According to Seriously Fish, kubotai are fine in 20-27 C and A. vespa are fine in 16-23 C. Considering these two fish are from identical habitats in the same river basins, I would take both of these temperature ranges with a huge grain of salt. I wouldn't be surprised if both fish could live in 16-27 C water just fine. Where I live, an indoor, unheated tank will be >20 C most of the year especially when you factor in lights and filter bumping up the temp. Occasional dips below 20C really shouldn't be a problem for the kubotai.

Then you should be fine

Happy day...I too love the UNS tanks and have 2 so far. I was wondering how this build turned out. I am interested in building a river tank that features stiphodon and am collecting ideas now.

Heterandria Formosa would be ideal, North American native as well, but you’re water looks slightly too soft. If it could be hardened? Though they do like plants too hide in...a few caves perhaps if you’re plant averse? I’ve 8-10 going into a species 10G sometime this week.
Its difficult this perfect set up lark isn’t it?
Best of luck whatever you choose.