Who Gives A Fish Forums

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.