Are Silver-tips usually aggressive?

[GwaiMui]

Hi there

Hoping someone can help with this.

I have a 60 litre tank with two Opaline Gourami's, two Albino Red-Fin Sharks, three Glowlights, and five Neons. I introduced the Silver-tips to the tank about a month and a half ago. At first, everyone was happy, they all got along, however, the last few weeks they've started chasing all the other tetra's. I've kept Silver-tips in the past and never had any trouble with them, they've always been really peaceful and go about their business not bothering anyone else in the tank. However, with these three new ones it's totally different.
Usually my tetra's are out and about, but since the Silver-tips have started bullying they all hide behind the plants and only come out to feed.

After a few days of this I couldn't stand seeing my other tetra's lurking in the shadows, so I moved the three Silver-tips over to my other (smaller) tank on their own. Since they've been there the other tetra's have gone back to their old selves and seem to be happy again.
However, the Silver-tips have been showing some really strange behaviour, now they're in the other tank, there's only one of them who chases the other two around, he won't leave them alone, the other two just hide all the time now.
The worst thing is, the two who are being bullied act as though they're dead, this morning two of them were stuck against my filter, I thought they'd died, but when I went to fish them out they swam off?? Right now, one of them is sitting nose down in the branches of one of my plants, looks dead, but nope, the second the bully comes over, he's off again.
They've been doing this for a few weeks, one is perfectly fine (the bully) but the other two just don't want to know.
Last week I felt so sorry for the two who were being bullied I switched them back over to the original tank, but as soon as they got in there they had a new lease of life and started attacking my other tetra's again! I can't win!
The Silver-tips are back in the smaller tank together, one's continuing to bully the others who are back to playing dead again.

I really don't know what to do as I don't want to keep them locked up from the other fish as they look so unhappy, but I don't want my other fish to be constantly bullied and spend the rest of their lives in the plants.

Any help with this would be greatly appreciated.

Many thanks, Emma.

 

[Lateral Line]

There are a few issues here.

Silver Tips are not real terrors, but are quite a punchy little tetra and will tend to be dominant over other similaly sized tetras.

Second, when moving tetras and many small fish to new quarters, there will be a period of adjustment where the pecking order of the new fish is sorted out, amongst themselves and amongst them and their new tank mates. This usuall lasts a few days to a week. Rarely does it do any serious damage. Once the superiority of the new alphas is determined, the subordinate members of the new group, and of the community return to normal.

With most of these small shoaling fish, you are best off with a larger group. A small group, (3 fish is barely a group), doesn't have the buffering capacity of a large group and often a dominant fish will chase and peck a subordinate to death. With a larger group, this behaviour is "dilluted" amongst the group. I would always advocate keeping at least 6 Neons/Glowlights/Silver Tips.