New tetra not eating

[nicki84]

I have a ten gallon with several shrimp and a snail. I also have had two black tetra for about 6 months. (Started with four but lost two to dropsy recently)
After getting my tank back to healthy, I added another full grown black tetra who seems to be acclimating well and schooling with the other two blacks. I also added three baby neons to the tank and they’re the ones I’m concerned about. When I feed the tetras, the neons don’t eat. I can’t just wait because the blacks eat it all up too quickly. I did use my net to isolate the three neons and tried feeding just in the net, but it was almost like they didn’t even recognize that food was present. I only added them yesterday so I’m guessing they’re just stressed a bit from the new environment, but with other hungry tetra in the tank I’m worried they’ll never be brave enough to get food before the blacks eat it all. What can I do to make sure the neons eat?

 

[Andy Sager]

For starters, a 10 gallon tank is too small for full size Black Tetras and the intimidation the smaller neons probably felt is most likely why they didn't eat. To help them out, you should have isolated the black tetras and let the neons eat first in their environment instead of the net, which is a strange environment to them.
I suggest you rehome the black tetras and stick with other small species of Tetras like Glo-lites or Ember Tetras or other micro rasbora species.

 

[Aiken Drum]

This comes down to stress in an aquarium. You have several factors causing stress.

• New fish moving into a new environment. It's not uncommon for new fish to take a few days to get comfortable in their new home before they start feeding.
• The fish you are keeping are social fish and they need to be kept in groups to feel comfortable. 3 fish is better than 2, 6 fish is better than 3, 10 fish is better than 6. But really the magic number for social fish that is commonly arrived at is 6 fish of the same species for them not to be stressed.
• A 10g aquarium isn't big enough for black tetras. I presume you mean either black skirt or black phantom tetras? They are both similar species, and both species would be better in double the aquarium size. I keep black phantoms, I'd probably be happy keeping them in 15 gallons if it were a single species tank, but 20 gallons would be my minimum for keeping them with other fish.

These factors will combine to make your aquarium a stressful environment for your fish. Stressed fish will act unpredictability. They might get aggressive towards each other. They might not eat. They might hide.

They might just make the best of the situation and get on with things. But that's not what you are seeing. Remove the stress in the aquarium.

If you want to keep these 2 species together they need a bigger home. 20 gallons would be big enough for each species to find its own space. You could also keep them in sufficiently sized groups. Say 6 black tetras and 10 neons.

If you are set on keeping the 10 gallon, the neons suit this size aquarium more than the black tetras. Rehome the black tetras either to a new aquarium of 15 gallons minimum or back to the store. Or maybe you can find another hobbyist who could take them.