Mixing juveniles and adult fish?

[Morainy]

Hi Everyone,

Last week, I got 50 very tiny red phantom tetras from a pet store. Fifty is a lot of fish for this size tank (36 gallon bowfront) but the fish are so small that I had to put a sponge over the Aquaclear's intake tube because one of the fish was sucked up it before my eyes.

The little horde of phantom tetras school together fabulously, the best I've ever seen in fish. They seem to be having a great time swooping around the tank.

The same store now seems to have extra large red phantom tetras. I am wondering what would happen if I added 5 or 6 adult phantom tetras to this group? They'd be bigger (I'm guessing over an inch long) and they'd likely be a bright red, while all the juveniles are still clear silver.

I know that the adult tetras wouldn't hurt the little ones because they're too big to eat. But, would their presence disrupt the schooling behaviour? Would they school together? Would it look odd to have the big red ones schooling with a group of teeny silver ones?

I've never had so many of one kind of fish before, so this is new for me in terms of fish psychology, lol.

The tank is planted, has an Aquaclear 70 and a Fluval 205 running. When the juvenile fish grow, I will get a bigger tank but right now, they really are midgets. Even as adults, phantom tetras are only 1.5 inches

[jobber604]

Exciting to hear about a shoal of tetras .
If you want to buy the bigger ones, they'll school together still. I've introduced different sized cardinals and they behaved the same. They're the same species and it'll provide for a safer environment in numbers.

I would give the tiny ones about a week. You'll be surprised how fast tiny tetras grow when you feed them daily.

Any videos to share? haha

[onefishtwofish]

the babies may still see the bigger ones as preditors and just hide. I think thier carefree attitude will change. The little fish don't know they won't fit in the big guys mouth.
just my opinion.

[Morainy]

Thanks, jobber604 and onefishtwofish!

Sorry, no video, jobber! That's a good idea, though I'm not very artistic with my tanks (cords clearly visible)...

[jobber604]

Cords or no cords, a school of 50 tetras is an amazing spectacle. Once they grow big, the colour of fish will look so nice.

It'll be nice to raise these little guys from tiny tetras through to adulthood. lucky you.

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[Morainy]

Thank you, Jobber604~! I'm pretty excited.