What about a severum? Yes they will probably get some of your neons, but a shoal as big as you’re getting, I imagine if you kept the severum fed, it would see going after the tiny neons as not worth the effort most of the time since picking off one out a large shoal is much harder than if you had 10 or 12 neons, and you could just replenish the neons periodically if it did grab a few
I ironically already had one (the 125 came with a bunch of mixed species cichlids, mostly large super aggressive types like red devils and green terrors) and rehomed it recently with the rest. Given that it was already an adult it was probably for the best anyway.
How about cupid cichlids, Biotodoma cupido? In my opinion, these are one of the most underrated SA cichlids around. They are gorgeous; pictures don't do them justice. They're sand sifters, and I think I'd actually consider keeping neons with these guys. I had five some years ago, two males and three females, and they didn't get overly aggressive even when the males were fighting over a female or territory. It was mostly just display and didn't even involve much jaw-locking. They didn't bother the glowlights or diamond tetras at all, and only bugged the cories when the cories got in their faces while they were sifting. That was just running the cories off and out off the way so the cupids could go back to their sifting. They didn't uproot the cabomba or the dwarf chain swords, they just sifted around them. They max out around 4" to 4-1/2". I've wanted to keep them again recently, and they're for sale a lot more often these days than they used to be. They're on my list to order once the weather warms up.
WYite
Look like slightly smaller, more colorful keyhole cichlids, interesting. Dunno if I could find any around where I live though (would like to try and buy locally just because the shipping tends to add such a hefty bump in price).
However, I have another issue to discuss. I was going to get my current fish in a 55 gallon down to two, but I had a long talk with my mother yesterday (she's getting very impatient about how long it's taking as she wants the 55 dismantled and sold ASAP to make room for furniture that was moved by the addition of the 125) and she lamented about how "I have responsibility" regarding the fish I already have.
To give a rundown, there's currently 4 clown loaches, 2 upside-down catfish, 1 Australian rainbowfish, 1 giant danio, 1 albino rainbow shark, and two bristlenose plecos.
The loaches are for sure getting rehomed as I've learned even a 125 won't be big enough for them in the long run and there's a more than decent chance they'll be too disruptive and dig out any plants I try to grow. And as mentioned before they've learned they can eat anything small tetra-sized. Ironically getting the 125 was originally with them in mind but the research I did after the fact showed it clearly wasn't meant to be, hence my new change in direction with what I want to do with it.
But the rest are what my mom's chastising about. The rainbowfish and danio are remnants of a mixed school and in their twilight years so I think they can stay and live out the rest of their days with me. They don't "fit the theme" but oh well (yes I am aware they need to be in schools but they're both so old that there wouldn't be much point).
The UDCs probably
could be rehomed, but they've had a major finrot problem in the past and never fully recovered (one effectively looks like a swimming slug) so idk if anyone would want to take fish in such sorry shape.
The rainbow shark I'm, iffy on. It's perfectly healthy but I'm concerned about its territoriality. It's been fine for most of the time, but there was one instance where I added an extra log hide so the fish could have more choices. Well, the clown loaches all crowded into the new one, which led to the shark going mad with power and completely taking over half the tank. Quickly removed the extra log so the loaches would go back to the old one and restore the social balance, but with that in mind it leaves me worried about what will happen if the shark moves into the new tank without the loaches to keep it in check, that it will become a tyrant and attack anything new I add to the tank.
The bristlenoses are for sure staying. One is much younger, about half grown and I believe female (next to no bristles) while the other is a adult albino male that came with the 125 and is currently bunking in the 55 as the bigger tank has been undergoing a complete revamping.