20 gallon high

I wouldn't say "better", both tetras can handle higher temps & are likely too big for betta snacks (as adults). I find both to be attractive :) I haven't kept giant bettas so I'm just guessing on that part.

I loved my kuhlis! I kept both striped & black. I prefer the striped for mellowness (less hyper) & prettiness. There are a few species of each; as always, try for all the same kind. My stripes (p. cuneovirgata) & blacks (p. oblonga) didn't interact at all except for a bit at feeding. No fighting but no mixing. I would say 8 is a good number for your tank.
 
I like the colors of rummynoses. Was debating them or silvertips.
I saw a listing for neon kuhli loaches, real name Sumatran Neon Loach (Pangio Bitaimac), they only get to 2.5-3” like the striped kuhlis. May get them, if I want 8 I have to order 10. Tank is over filtered so should be fine. The listing is only for 5 loaches.
 
I vastly prefer rummies to silvertips. I've only kept silvertips once & pretty as they are, they were quite aggressive to each other & to other similar sized species. I wondered if they are always that way of if mine may have been "hormoned".

I've kept rummies several times, never a problem except maybe ich once...

That's a new pangio species to me. They look a lot like what used to be p. doriae, maybe different or a new name for an old species? I don't think there are any "bad" pangios, just get a bunch & see ;) & then tell!
 
I came home to 3 out of 5 rummynose tetras and giant betta dead. They were alive and ate when i left for work. I check new fish daily and none showed signs of illness. I know rummynoses can be iffy and I don’t have the greatest success with them. I did a water test and it was perfect.
ph 7.8
Nitrite 0ppm
Ammonia 0ppm
Nitrate 10ppm

heater and filter are working properly and shrimp are thriving so not sure what happened.
 
Id opt for the dwarf gourami, cardinals, and kuhlis
 
Oh gee, I'm sorry. I would wait to add new fish until you're sure there's no spreading illness going on. That was so fast, I hate mystery deaths...

I know you considered moving the clown plec but wait for tank health before you do.

I wouldn't get apistos or rams, too many low level fish. I wish dwarf gouramis were healthier these days but I vote no. Maybe honey gouramis or a betta. So, are you giving up on rummies for this tank?
 
I’ll stick to the betta then. I’m going to wait a week or two before adding anything else to the tank. Going to bring up the heat as well and add some meds for the pleco.
It was just sudden, had similar happen when my heater surged and killed most of my 40 gallon but the heater is fine in the 20.

kuhlis maybe to active for a 2’ tank and I really like the pygmy corydoras.
 
I been checking the pleco and shrimp and they seem to be doing well. I did a water change and moved things around. Probably change up the stocking but still thinking. Testing the water shows no ammonia or nitrite just nitrate around 10ppm.
 
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