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How much water do y'all change weekly for adult Discus in a 75 gallon? I've been doing 50%, but my buddy says that's overkill. Tank's got sand substrate, driftwood, and a Fluval FX4. Params are stable, 0 ammonia, 0 nitrite, 10 nitrate.

50% ain't overkill if your nitrates creep up. Mine's a 90 gallon with 12 adults, and I do 60% twice a week. Key is matching changes to bioload. What's your stocking like? Also, what temp you running?

guyah wrote: ↑Mon Jun 16, 2025 1:36 pm 50% ain't overkill if your nitrates creep up. Mine's a 90 gallon with 12 adults, and I do 60% twice a week. Key is matching changes to bioload. What's your stocking like? Also, what temp you running?

Agreed. I do 50% weekly on my 75 with 8 Discus, but bump to 70% if nitrates hit 15. Temp at 84°F, and they're thriving. Overfiltering helps, but nothing beats fresh water.

Your buddy's sketchy advice might work for tetras, not Discus. They're messy eaters, especially if you're feeding beef heart. Stick with 50% unless your tap's got weird vibes (chloramines, etc.). Test before/after changes to dial it in.

I do 30% weekly in my 55 gallon, but only got 4 juveniles. Should I up it? Running a canister filter, planted tank with CO2. Nitrates stay under 20.

abbeytone wrote: ↑Mon Jun 16, 2025 4:54 pm I do 30% weekly in my 55 gallon, but only got 4 juveniles. Should I up it? Running a canister filter, planted tank with CO2. Nitrates stay under 20.

Nah, you're good for now. Juveniles need cleaner water though, so maybe 40% once they hit 4 inches. Watch for stunting.

My tap's got high phosphates, so I cut changes to 25% but add Purigen. Works okay, but Discus colors pop more after bigger changes. Tradeoffs, man.

Y'all overthink it. Just change water when it looks dirty. My Discus are fine, and I barely test. Tank's been running 2 years, no crashes.

Appreciate the input, folks. Gonna stick with 50% and monitor growth. Forgot to mention I feed twice daily, mix of flakes and frozen brine. Maybe that's why my nitrates climb.

virus wrote: ↑Mon Jun 16, 2025 6:28 pm Y'all overthink it. Just change water when it looks dirty. My Discus are fine, and I barely test. Tank's been running 2 years, no crashes.

That's playing with fire. Discus hide stress till they're on death's door. Test weekly, or don't keep 'em.