why discus swim near surface?

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tigercub
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Joined: Fri Apr 01, 2022 2:17 am

why discus swim near surface?

Post by tigercub »

Noticed my discus hanging out near the top of the tank a lot lately. Water params are good, 0 ammonia, 0 nitrite, nitrate around 10 ppm. Tank's a 75 gallon with sand substrate, driftwood, and some Java ferns. Temp's steady at 84°F, running a Fluval FX4. They're eating fine but just seem to chill up there. Anyone else seen this?
Wind
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Joined: Wed Oct 23, 2024 5:25 pm

Re: why discus swim near surface?

Post by Wind »

Could be a few things. First, check if they're gasping. If they're gulping at the surface, it might be low oxygen. Try increasing surface agitation with an airstone or adjusting your filter output. Also, what's your feeding routine? Overfeeding can mess with water quality even if params look good. I'd do a 30% water change just to be safe.
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jiffix
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Re: why discus swim near surface?

Post by jiffix »

Yo, my discus did this too when I had a sketchy heater. Temp swings freaked 'em out. Double-check your heater's working right, maybe grab a backup thermometer. Also, how old are they? Juveniles sometimes act weird just 'cause they're still figuring things out.
Swiftsea
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Re: why discus swim near surface?

Post by Swiftsea »

jiffix wrote: Thu Jun 05, 2025 12:20 pm Yo, my discus did this too when I had a sketchy heater. Temp swings freaked 'em out. Double-check your heater's working right, maybe grab a backup thermometer. Also, how old are they? Juveniles sometimes act weird just 'cause they're still figuring things out.
Good point on the heater. Tigercub, what's your photoperiod? Too much light can stress them, especially if they're new to the tank. I'd cut it back to 8 hours max if you're running longer.
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Dawn
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Re: why discus swim near surface?

Post by Dawn »

Mine did this when I first added them! Took about a week to settle. Are they new? If so, give 'em time. Also, what tankmates you got? Nippy fish can make discus nervous. My crew chilled out once I moved the tetras to another tank.
buzzit
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Re: why discus swim near surface?

Post by buzzit »

Seconding the oxygen thing. I had this issue in my 90 gallon until I added a second sponge filter. Now they swim mid-level like they're supposed to. Also, what's your pH? Discus can get weird if it's too high or fluctuating.
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tigercub
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Re: why discus swim near surface?

Post by tigercub »

Thanks for the tips, everyone. Gonna test the heater and grab an airstone today. They're about 6 months old, and yeah, I've got some rummynose tetras in there. Maybe that's the issue. Appreciate the help!
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jellybelly
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Re: why discus swim near surface?

Post by jellybelly »

Had the same problem last month. Turned out my canister filter was clogged. Flow was down to a trickle, so oxygen dropped. Cleaned it out and they were back to normal in a day. Might be worth checking your FX4.
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ameRio
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Re: why discus swim near surface?

Post by ameRio »

Y'all sleeping on the simplest answer. Sometimes they just like it up there! My big blue diamond hangs at the top every afternoon like clockwork. No issues, just vibes. But yeah, rule out the serious stuff first.
dawny
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Re: why discus swim near surface?

Post by dawny »

ameRio wrote: Thu Jun 05, 2025 7:14 pm Y'all sleeping on the simplest answer. Sometimes they just like it up there! My big blue diamond hangs at the top every afternoon like clockwork. No issues, just vibes. But yeah, rule out the serious stuff first.
True, but better safe than sorry. Tigercub, you running CO2? Even low levels can push fish to the surface if it's not dialed in right.
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