Who Gives A Fish Forums

I've got a group of 5 Discus in a 75-gallon tank, and one of them is constantly chasing the others. Water params are good, 0 ammonia, 0 nitrite, 10 nitrate, pH 6.8. Temp is steady at 84°F with a Fluval heater. They're fed twice a day with a mix of frozen bloodworms and Hikari pellets. Anyone else dealt with this? It's stressing me out.

Yep, seen this before. It's usually a dominance thing. Try adding more hiding spots with driftwood or plants. I used Java fern and it helped chill the vibe. Also, maybe bump up feeding to 3 times a day so they're less hangry.

Had the same issue with my group. One dude was a straight-up bully. I moved him to a quarantine tank for a week, and when I put him back, he chilled out. Weird, but it worked. Tank's got sand substrate and a canister filter, if that matters.

Aw, poor fishies. I'd try rearranging the tank decor to shake things up. Sometimes a new layout resets the pecking order. My Discus are in a 55-gallon with a sponge filter, and they're doing great now. Good luck!

Dominance behavior is common in small groups. Ideally, you'd have at least 6 to spread aggression. Your water params sound solid, but make sure your filtration is robust. A 75-gallon should handle a bit more bioload if you decide to add another.

Thanks for the advice, everyone. I'll try adding more plants and maybe another Discus. Appreciate the help.

Yo, same thing happened to me. My bully fish was a jerk until I added some dither fish like tetras. Now he's too busy showing off to chase the others. Tank's got a black background and LED lights, which might help too.

talon wrote: ↑Mon May 05, 2025 9:56 pm Had the same issue with my group. One dude was a straight-up bully. I moved him to a quarantine tank for a week, and when I put him back, he chilled out. Weird, but it worked. Tank's got sand substrate and a canister filter, if that matters.

That's interesting. I've heard temporary separation can work. My tank's got a similar setup, but I haven't needed to try it yet.

Lol, fish drama. My Discus were like that until I switched to a bigger tank. Now they've got space to avoid each other. 125-gallon with a sump, and they're way happier. Maybe your bully just needs more room to flex.

Mine did this too. I cut the lights for a few days and they calmed down. Tank's got a sponge filter and bare bottom, so maybe less stress overall.