I have 2 serpae tetra, and they seem really agressive. they have killed of 2 of my glowlight tetra already and heavily nipped at another. are they usually very agressive? i was led to believe they were ok as community fish
I will try and not to rant here. I had some Serpae tetras kept with Glowlights and a few different tetras and they attacked the others so much. So I got 6 of them, as I was told they would share agression within themselfs, but it made them worse, they hunted in packs. If I was you I would take them back to LFS they are not worth the hassle.
My neighbours son recently started a tropical tank and was advized that these were okay community fish and was told that straight after setting up he could put in 4 serpae tetras, and these were okay and all survived, and then a week later he was told it was okay to put 4 glowlight tetras and 4 rummynose tetras in with them, then serpae tetras have since killed off two of each. I've never kept them myself but judging by this and what I've read on this forum previously, they aren't very good community fish and can be aggressive / fin-nippy