Discus tank plant fertilizer risks

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angelus
Posts: 20
Joined: Wed Oct 23, 2024 10:23 am

Discus tank plant fertilizer risks

Post by angelus »

I've been using Seachem Flourish in my 75-gallon Discus tank with Amazon swords and Java ferns, but I'm worried about the impact on my fish. The tank's been stable for months, 0 ammonia, 0 nitrite, 10 nitrate, pH 6.8, temp 84°F. Anyone else run into issues with ferts stressing them out? My group of six are adults, fed twice daily with frozen bloodworms and pellets.
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kayla
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Joined: Tue Jul 05, 2022 1:14 am

Re: Discus tank plant fertilizer risks

Post by kayla »

Seachem Flourish is generally safe, but Discus can be sensitive to trace elements like copper. I'd check the label for heavy metals. My 120-gallon planted tank has similar params, and I dose Flourish Trace instead, which is formulated to be gentler. How often are you dosing? Weekly water changes help prevent buildup.
Boldy
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Joined: Mon Jan 17, 2022 7:30 am

Re: Discus tank plant fertilizer risks

Post by Boldy »

Yep, gotta watch those ferts. Had a sketchy vibe when I tried API Leaf Zone in my setup, my fish started acting weird, like hiding more. Switched to DIY root tabs and cut it with the liquid stuff. Tank's chill now, 55-gallon with sand substrate, sponge filter, and a pair of breeding Discus.
boldo
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Joined: Sun Jul 17, 2022 10:04 am

Re: Discus tank plant fertilizer risks

Post by boldo »

Boldy wrote: Sat Aug 09, 2025 7:13 pm Yep, gotta watch those ferts. Had a sketchy vibe when I tried API Leaf Zone in my setup, my fish started acting weird, like hiding more. Switched to DIY root tabs and cut it with the liquid stuff. Tank's chill now, 55-gallon with sand substrate, sponge filter, and a pair of breeding Discus.
Root tabs are a solid move. I've had success with Osmocote Plus capsules buried under gravel in my 90-gallon. Less water column mess, and my Discus don't react. Key is keeping macros balanced, so I test phosphates weekly.
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kicks
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Re: Discus tank plant fertilizer risks

Post by kicks »

My crew's fine with Thrive C, but I only dose half the recommended amount. 65-gallon, CO2 injected, LED lights on 8 hours. You might wanna dial back the Flourish and see if they perk up. Also, how's your oxygenation? High temp plus ferts can sometimes mess with O2 levels.
angelus
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Joined: Wed Oct 23, 2024 10:23 am

Re: Discus tank plant fertilizer risks

Post by angelus »

Thanks for the tips, everyone. I'll try reducing the dose and maybe switch to root tabs. Gonna test copper levels too, just in case.
SlateFang
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Joined: Thu Oct 10, 2024 3:41 pm

Re: Discus tank plant fertilizer risks

Post by SlateFang »

Nope, never had probs with ferts, but my tank's low-tech, no CO2. Just a basic LED and weekly 30% changes. Discus are juvies, so maybe they're hardier? Dunno, but I stick to Easy Green, seems to work fine.
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kayla
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Re: Discus tank plant fertilizer risks

Post by kayla »

kicks wrote: Sat Aug 09, 2025 9:26 pm My crew's fine with Thrive C, but I only dose half the recommended amount. 65-gallon, CO2 injected, LED lights on 8 hours. You might wanna dial back the Flourish and see if they perk up. Also, how's your oxygenation? High temp plus ferts can sometimes mess with O2 levels.
Good point on oxygenation. I run an airstone at night in my high-tech tank. Angelus, if you're not already, consider a surface skimmer or increasing surface agitation.
Ridgerider
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Joined: Sat Oct 12, 2024 6:30 pm

Re: Discus tank plant fertilizer risks

Post by Ridgerider »

I don't use ferts. Just natural mulm from the sand and driftwood. Fish seem happy, 40-gallon with five Discus and some tetras. Less stuff in the water, less to worry about.
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silence
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Joined: Mon Jun 06, 2022 3:00 pm

Re: Discus tank plant fertilizer risks

Post by silence »

My tank crashed once from over-fertilizing. Lost two Discus. Now I only dose after testing, and only if plants show deficiencies. 50-gallon, canister filter, no CO2.
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