Green neon tetras disappear in the night.

[a.stoner]

I recently bought 12 half inch or so green neon tetras. They swam around fine throughout the day.. but when I turn the lights out for the night and come back the next morning. Some of them disappeared. It’s been happening every night, same routine, now I’m down to just one left. I can’t seem to figure out if they are getting eaten in the night or who is doing the eating.
29gallon tank
10 guppies
6 black neon tetras
1 betta fish
2 glass painted fish
6 banded Kuhli loaches
2 dwarf syn. Petricola catfish
1 remaining green neon tetra
3 Amano shrimp.

 

[fishorama]

How big are your petricolas? If you had just gotten the green neons, they may have died for whatever reason & been eaten by almost any fish or shrimp...I don't suppose you quarantined them before adding them to your tank?

 

[a.stoner]

How big are your petricolas? If you had just gotten the green neons, they may have died for whatever reason & been eaten by almost any fish or shrimp...I don't suppose you quarantined them before adding them to your tank?

The petricolas are about an inch and a half. No bigger than 2 inches. There’s no traces of tetra bodies anywhere.

 

[dudley]

Is the tank completely covered with a lid with no gaps for fish to jump out?

 

[a.stoner]

Is the tank completely covered with a lid with no gaps for fish to jump out?

Yep, completely covered with a glass top.

 

[The GingerFishman]

You'd be surprised how quickly the shrimp and other fish can consume a dead fish. Have you checked your Ammonia, Nitrite and ph levels? Sometimes, if there's traces of ammonia, the new fish can't tolerate it because they're not acclimated to it, but your current fish would have slowly built up some level of tolerance to low levels of ammonia. Nothing in your tank fits the bill as a predatory fish. The petricolas are too small *but* if your fish succumb over night then they would quickly consume them along with the shrimp and you wouldn't see a scrap left over. That is my guess as to what is happening - for comparisons sake, I have Cardinals in a small tank with the same type of catfish and there's no issues. Take some water tests if you haven't already and see if the parameters come in ok

 

[ustabefast]

also, check your Nitrate level if you can.
Long term fish can acclimate to rising high Nitrates that may kill introduced fish.

 

[ustabefast]

Oh, also the Betta could be the culprit. Does he or she play nicely with the others?