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Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 1:11 am
by Jumper
My Discus fry tank's pH keeps swinging from 6.8 to 7.4 after water changes. I'm using RO water with a remineralizer, 50% changes twice a week, and a sponge filter. Tank's at 84°F, no tankmates, just a bare bottom. Any tips to stabilize it without stressing the fry?
Re: Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 3:13 am
by Misty
RO water's tricky because it lacks buffering capacity. Try adding crushed coral or aragonite in a mesh bag near the filter. It'll dissolve slowly, keeping pH around 6.8–7.0. I've used this in my 20-gallon fry tank with a Tidal 35 filter, and it's been steady for months.
Re: Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 3:52 am
by Wildman
Misty wrote: ↑Fri Sep 19, 2025 3:13 am
RO water's tricky because it lacks buffering capacity. Try adding crushed coral or aragonite in a mesh bag near the filter. It'll dissolve slowly, keeping pH around 6.8–7.0. I've used this in my 20-gallon fry tank with a Tidal 35 filter, and it's been steady for months.
Yep, coral works. I toss a handful in my canister filter's media tray. Also, cut your water changes to 30% if the swings are bad. Fry hate instability.
Re: Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 8:45 am
by angelus
Slang aside, you gotta chill with the big water changes, mate. Tiny fry tanks are like a moody artist, sensitive to everything. Dial back to 25%, use Seachem Acid Buffer if you're fancy, and test daily. My 15-gallon's been golden since I slowed my roll.
Re: Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 9:56 am
by turret
Agree with reducing change volume. Also, ensure your remineralizer includes carbonates. I use Salty Shrimp GH/KH+ at 100 ppm KH, which buffers better than most. Tank's 29 gallons, planted with driftwood, and pH stays at 6.9. Fry are thriving.
Re: Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 12:14 pm
by Jumper
Thanks, all. Gonna try the coral and smaller changes. Appreciate the specifics!
Re: Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 1:04 pm
by BoldRom
If you're still seeing swings, check your tap's KH before mixing RO. My local water's KH is 2, so I blend 70% RO with 30% tap to keep things stable. Heater's an Eheim Jager, set to 86°F for fry growth.
Re: Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 1:04 pm
by BoldRom
If you're still seeing swings, check your tap's KH before mixing RO. My local water's KH is 2, so I blend 70% RO with 30% tap to keep things stable. Heater's an Eheim Jager, set to 86°F for fry growth.
Re: Discus fry tank water buffer tips
Posted: Fri Sep 19, 2025 1:46 pm
by Magpie
BoldRom wrote: ↑Fri Sep 19, 2025 1:04 pm
If you're still seeing swings, check your tap's KH before mixing RO. My local water's KH is 2, so I blend 70% RO with 30% tap to keep things stable. Heater's an Eheim Jager, set to 86°F for fry growth.
Solid advice. Also, skip the remineralizer if blending tap. My fry tank's a 40-gallon with sand substrate, and I just age the mix overnight with an airstone. pH stays put.
Re: Discus fry tank water buffer tips
Posted: Mon Sep 22, 2025 10:33 am
by swiftly
Weird vibe, but my fry did better when I stopped chasing numbers. As long as ammonia's zero and temp's steady, they'll adapt. I use a cheapo sponge filter, feed live baby brine, and ignore my test kit unless fish act off.