[Srg999]

I have questions can I mix 2 piranhas(approximately 6-7inch) with 4 piranhas (approximately 3-4inch) they are very aggressive than 6-7 inch piranhas and eat very fast , I have them in one tank with divider (3 weeks ago) should I wait more ?

 

[LdnErin]

In my experience yes you can mix them (provided the divider time gave a positive result). But before you do some there are several questions: First of all, (1) what's the size of the tank? a good space for all piranhas is vital for them to get along. (2) You mentioned the 3-4inch are more aggressive than the 6-7, does that mean against each other (within their group) or against the other group?

 

[Srg999]

Thanks for replying, My tank size 615 L and what I mean when I said aggressive they eat very fast within their group (live or frozen food), the bigger ones eat slowly

 

[Ægir]

6 in a tank that size will be fine, your problem will be territories like the plants and rocks. I would introduce the smaller ones with a divider or during a large water change / when you take things out or major decor rearrange.

 

[Srg999]

Everything is ok, I did major decor rearrange and they swimming together like one pack + they are very active now
Thanks all.

 

[LdnErin]

Awesome! Yeah they should be fine. Congrats!