Help! One platy is beating up the other Three!
 

I'm cycling a 20 gal. I'm about 2 1/2 weeks into it. I started with 1 female betta and a week later added 2 platies. A week later the betta started looking stressed so I took her out because I thought the cycle was getting to her. I bought 2 more platies because my first 2 looked like they were having the time of their lives and water conditions were still pretty good. That was about 3 days ago. As soon as I added the new platies, one of my old platies ( we will call him Sunny) decided to become the boss of the tank. He has been chasing all three other platies to the point where they hide all the time! I finally stuck Sunny in a breeder box about 2 days ago and he has yet to chill out! Meanwhile, calm has returned to the rest of the fish. Sunny's original buddy spends a lot of time up by the breeder box which I find endearing and yet worrisome. How do I bring peace to my tank? Any tips from experienced fish keepers?

What are the water parameters on your tank, what is the level of your ammonia, nitrites and nitrates? Also what is the sex of the other 3 platys? Please take the one platy out of the breeder box, breeder boxes are very stressful on fish, I don't even use them for my females, but place the female into a seperate tank of her own to drop her fry when wanting to raise them. Otherwise I leave them in the community tank. If you are going to keep different sexes together on livebearers it is best to keep them in at least a ratio of 2:1 females to males, and even 3 females is better.

Thank you for answering me! I understand its stressful on Sunny. I don't like it at all. But my other three fish are SO MUCH HAPPIER!! So I'm kinda stuck between a rock and a hard place on this one. My water parameters are hardly even worth noting. I have live plants and the tank is hardly even registering any ammonia yet. I seeded it with another filter and I have just barely started to see nitrates, but the nitrites have not shown up on the tests yet either. I did a lot of research before I started on the tank and the plants and the cycling, but apparently not enough on how to make platies get along. Any other suggestions?

I would suggest not letting him return to the community. I had to get rid of one of my male platies for the same reason.
Posted via Mobile Device