Discus tank bioload management

Chat about all things related to Discus, from purchasing to breeding and everything in between. One of the most beautiful species in the hobby
landfall
Posts: 5
Joined: Thu Oct 10, 2024 3:40 pm

Discus tank bioload management

Post by landfall »

Been struggling with my 75-gallon tank's bioload lately. Got 6 adult Discus, a school of 12 Cardinals, and 6 Corydoras. Running a Fluval FX6, weekly 50% water changes, but nitrates creep up to 40ppm by day 5. Anyone got tips to keep it stable without upping water changes?
Dkade
Posts: 5
Joined: Mon Nov 14, 2022 1:59 am

Re: Discus tank bioload management

Post by Dkade »

That's a heavy load for a 75. I'd cut feeding to once daily, skip a day weekly. Also, try adding more plants like Amazon swords or floaters. They'll help suck up nitrates. My tank's similar, and that combo keeps nitrates under 20ppm.
User avatar
Tonito
Posts: 6
Joined: Wed Jan 03, 2024 4:45 am

Re: Discus tank bioload management

Post by Tonito »

Agree with Dkade on plants. Also, check your filter media. If it's packed too tight, flow drops and nitrates spike. I run sponges plus Matrix in my FX6, spaced out. Nitrates stay below 30ppm with 8 Discus in a 90-gallon.
Dream
Posts: 5
Joined: Sat Aug 03, 2024 9:37 pm

Re: Discus tank bioload management

Post by Dream »

Tonito wrote: Sun May 25, 2025 12:12 am Agree with Dkade on plants. Also, check your filter media. If it's packed too tight, flow drops and nitrates spike. I run sponges plus Matrix in my FX6, spaced out. Nitrates stay below 30ppm with 8 Discus in a 90-gallon.
Second this. Media arrangement is key. Also, consider adding Purigen to your filter. It's a game-changer for nitrate control.
Olive
Posts: 9
Joined: Wed Jun 07, 2023 9:12 pm

Re: Discus tank bioload management

Post by Olive »

How often do you clean the FX6? Gunk buildup can turn it into a nitrate factory. I deep-clean mine monthly, rinse media in tank water. Also, what's your feeding routine? Overfeeding's usually the culprit with nitrate spikes.
landfall
Posts: 5
Joined: Thu Oct 10, 2024 3:40 pm

Re: Discus tank bioload management

Post by landfall »

Thanks, all. Gonna try the plant boost and Purigen. Didn't realize media spacing mattered—my sponges are jammed tight. Will adjust and report back.
metiteh
Posts: 6
Joined: Thu Oct 10, 2024 6:06 pm

Re: Discus tank bioload management

Post by metiteh »

If nitrates are still sketchy after tweaks, test your tap water. Mine's got 10ppm straight from the faucet. Had to switch to RO mix to solve my nitrate woes.
spance
Posts: 8
Joined: Wed Mar 23, 2022 11:27 pm

Re: Discus tank bioload management

Post by spance »

metiteh wrote: Sun May 25, 2025 4:50 am If nitrates are still sketchy after tweaks, test your tap water. Mine's got 10ppm straight from the faucet. Had to switch to RO mix to solve my nitrate woes.
Good call. Also, how old are your Discus? Juveniles poop way more than adults. My tank stabilized once mine hit 4 inches.
Fuegoz
Posts: 10
Joined: Thu Oct 10, 2024 3:42 pm

Re: Discus tank bioload management

Post by Fuegoz »

Yo, landfall, what's your substrate? Sand traps way more waste than bare bottom. I switched last year and nitrates dropped big time. Still got plants in pots though.
Lavida
Posts: 6
Joined: Thu Oct 10, 2024 3:33 pm

Re: Discus tank bioload management

Post by Lavida »

My tap's clean but nitrates still high. Gonna try them floaters like Dkade said. Heard water lettuce works good.
Post Reply