Aggressive discus HELP!

[kyle994]

I currently have 6 discus in a 50G tank, 5 that range between 3.5-4.5" and the big dog at roughly 5.5". For the last month big yellow has been chasing 4 of the fish to the back of the tank but "he" has never shown any aggression to the 5th fish, I'm putting it down to the fact that they have paired up. I was looking to purchase a second smaller tank to house them both in to give the others a break so they can finally have the full use of it. I guess my question is does anyone know if this is typical behaviour of a couple and would putting them in a second tank keep the bond or could big yellow end up turning on his friend in a new environment?. T.I.A

[LizStreithorst]

Give them a tank of their own. Peace will be restored and you will get baby fish

[BradGreenberg]

I have a similar problem with 6 discus in 75 gal. tank. I purchased 2" discus from a breeder. Two became ill (parasites), one died and he other sick fish, after two weeks ill became stunted and is in another tank as it is now healthy but very small. The other four fish grew and are growing and are now between 3" and 4." I ordered two fish from a different, but apparently world-renowned breeder. One fish, a "medium" sized, 3.5" to 4" and a large, "4.5" to 5." The fish arrived and to my surprise, they both were very large in that they were much more thick and round than the 4 original fish. The large fish was huge being close to 6". (the breeder from which I purchased the two fish breeds incredible fish) After acclimating, the new "large" fish began severely harassing the new "medium" fish to the point that I became concerned for the health of the "medium" fish. The new "large fish" on occasion, would act aggressively towards the much smaller original fish as well.

The tank, had 3 natural plants and 2 large plastic plants and substantial open areas. I do not want to maintain several fish tanks (2 is enough). I observed the fish for a few hours and noticed that the new "large" fish would only become aggressive with the "medium" fish if it could see it. There were several open spaces in the tank which the "large" fish could see other fish and attack.

I purchased several more plastic plant and after the next water changing, strategically placed them in the tank limiting lines of sight and leaving spaces where the fish, particularly the larger one, could mark as their own. The "large" fish now tends to stay on the right side of the tank and the others on the left and center.

Feeding time remains a problem, but I try to spread the food out as much as possible. Hopefully, all the fish will grow to roughly the same size and I can take some of the plastic plants out. The tank, currently, is not crowded with the plastic plants, but there are enough to make aggression and territory disputes more difficult.

There is one last surprising issue, for a little diversity, there are ten neon tetras in the tank, all fully grown and less than an inch and extremely passive. Nevertheless, the discus fish, all at least ten times their size, tend to avoid them.