In my 39g planted tank I've had a couple of schools my tank has been up and running a little over a year. Now I have four Rummynose, six Neons, three Diamond Tetras (I know they're best kept in bigger groups, but they've been in the tank the longest as they were my first and recently I tried to introduce another Diamond into their school and didn't want anything to do with him and I figured since they weren't aggresive to anyone and all seemed healthy and happy I'd just let them be and I took the fourth back) and a big Blue Gourami (she's been with them for about 6 months, it was a risk putting her in there but I've NEVER had an aggression problem and she loves playing in my bubbles witht the tetras)
My fish generally stay toward the bottom of the tank and play in the caves and driftwood I have, so I wanted fish that'll swim at the top, (I have a tall tank) so I decided on Zebra Danios. I had them in the past when I had tanks and remembered they were good little fish. With the introduction of the zebras (I got four) I noticed that the day after I introduced them, my schools had broken up..aside from the Diamonds who are still attached at the hip. But I would see a Rummy a Neon and a Zebra, playing in the bubbles and it seemed like the Zebras brought the Rummynoses to the top of the tank to swim.
I just wanted to double check that this shouldn't pose a problem of any sort? Because if it will I can take the zebras back, who might I add are fearless. One of them grabbed the other end of a bloodworm and took it from my Gourami, she didn't mind, however, she just grabbed another but she is four times it's size.
Your help is much appreciated, I just thought it strange because all the Neons I've owned in the past loved their tight knit groups.