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What's the best pH buffer for a Discus tank? My water's sitting at 7.8, and I need to bring it down to around 6.5. I've got a 75-gallon tank with six Discus, two German Blue Rams, and a bunch of Cardinal Tetras. Running a Fluval FX6, sand substrate, and driftwood. Tried peat moss but it's not cutting it. Any suggestions?

I've had great results with Seachem Acid Buffer. It's stable and won't crash your pH if you dose correctly. My 120-gallon is at 6.4, and I use it with RO water. Just make sure to test daily at first. Also, your driftwood should help over time, but it's slow.

flashy wrote: ↑Mon Jul 14, 2025 9:00 am I've had great results with Seachem Acid Buffer. It's stable and won't crash your pH if you dose correctly. My 120-gallon is at 6.4, and I use it with RO water. Just make sure to test daily at first. Also, your driftwood should help over time, but it's slow.

Yep, Acid Buffer's solid. I pair it with Alkaline Buffer to keep things steady. My tank's 55 gallons, pH 6.6, and I do 30% water changes twice a week. Discus are thriving.

I'm kinda new to Discus, but my LFS recommended API pH Down. It's working okay, but I'm nervous about overdoing it. Tank's 40 gallons, pH 7.0, and I've got three young Discus. How often do you guys adjust the buffer?

API pH Down is sketchy for long-term use. It can cause swings if you're not careful. RO water with a remineralizer like Seachem Equilibrium is safer. My 90-gallon stays at 6.5, and I only tweak the buffer after water changes.

Thanks for the advice, everyone. Gonna try the Acid Buffer and Alkaline Buffer combo. I'll report back in a week!

Don't forget to check your KH too. If it's too low, your pH will bounce all over. I keep mine at 3-4 dKH with a mix of crushed coral in the filter. 65-gallon tank, pH 6.8, and my Discus are chill.

I've been using peat pellets in my canister filter. It's a slower process, but my pH is a steady 6.7 in my 50-gallon. Takes patience, though.

Yo, just cut it with RO water straight up. No buffers needed if you mix it right. My tap's 8.0, but 50/50 RO gets me to 6.5. Easy peasy.

Buffers are a crutch. If you can't keep Discus in your tap water, maybe they're not for you. Just saying.