What would you suggest?

[puffarama]

I have a 30 gallon tank that used to contain six dwarf puffers. The biggest dominant male claimed the tank and one of the girls as his own. He killed one male and I removed the other male. Now one of the girls has bit one of the other girls (there were four in the tank, one male, girlfriend and two other girls) and she is in a hospital tank. Here is my dilemma, 30 gallons is too big for three fish. Should I give away the spawning couple because it would be right to keep them together and spawning. Should I give away the dominant male. Would I be able to add small puffers (small as in the size pet stores sell them) to the three that remain in the tank? I do not want to get out of puffers but I would like everyone to be housed appropriately. Suggestions? I am keeping the one that got bit in a 5 gallon for longterm because I don't want her to get hurt again.

[Dadof4]

Try breaking up sight lines with heavy vegetation.

[pufferpuggirl]

I have 8 dwarf puffers all living together and I never have any deaths (and I've had way more than that before), so I think you need to put more plants in, and as Dadof4 says, break up the lines of sight. Most of the time they will develop a pecking order and everything will be okay. Like I said, I've never had any deaths and usually they all get along very well together, but then the tank I have mine in is very complex, so maybe that's the key.

[puffarama]

the tank is heavily planted ... there is only a very small area of about five inches by five inches in the front centre that you can see the substrate, otherwise it is heavily planted ... and the plants have been growing well for a year so it is quite bushy and they definitely can not see across the tank in any way ... the dwarf puffers are all mature ... this is a video of my tank and it was taken 6 months or so ago and the plants are even fuller now, especially in the back left corner, do i need more plants than this ???

http://www.youtube.com/watch?v=rjcSL2xfPpE

[pufferpuggirl]

puffarama - I think your tank looks nice, nicely planted in fact. Maybe you could add some hiding places -- I use half coconut shells, small ornaments that they can go inside, home-made caves -- anywhere they can retreat to and feel like they have their own territory.
I honestly don't know why you're having so much aggression because I'm sure that I must have a few males in my tank as I don't bother trying to sex them, I just add puffers when I want to.

[Myaj]

Well, you can always try re-arranging the decor a bit. But if your breeding bunch is too aggressive to other dwarf puffers, you might want to just stick to them and then maybe add some other smaller, fast moving fish that they can get along with (are they harassing your otos at all?) Maybe some small rainbowfish or something like serpae tetras or rasboras...?