Is this agressive behavior?

[CT_]

I added a guppy(orange) and the yellow one was very interested in the new guppy.  when I released it there was one or two nips then just a lot of posturing and headbutting but not biting so I turned the lights off and put a towel over the tank until morning to let them cool off.  Its been just under a day now and things seem better but they still seem standoffish.  Is this okay behavior or should I try and mitigate it?  I was thinking of putting the yellow fish in time-out for a day or two to reset its territorial claims, which i read can fix the problem, but isn't sure fire.  I don't have another tank so I was just going to float him in a basket with opaque walls.

 

 

[Brandy]

Guppies aren't territorial really, so I don't think it will work. Males just do this. With females they spend a bit more time trying to mate, but without they just bug each other. It won't get out of control, they are amusing themselves, like boys roughhousing to see who is toughest, it will just be a constant pecking order test, with no real hard feelings. If you add MORE of them, it is more distributed and will actually settle down, also you can always feed a tiny bit to refocus them on something they love even more--FOOD!

[OceanTruth]

I didn't see much aggression, to be honest. Males do chase each other a lot, but they don't do any damage. I've never noticed any serious bullying either.

The flow on your filter seems to be a bit high. Looks like they were getting pushed around by the current a bit.

[CT_]

Heh, yeah okay.  Guppies seem pretty energetic and its hard for me to tell whats just guppy machismo and whats real aggression asides from biting which is pretty obvious.

 

Yeah I had the water lower but then got worried about O2 and turned it up.  I've got a micro pump and air stone coming so maybe I'll just turn it back down and run the air stone too if for no other reason than alleviate my paranoia.