Who Gives A Fish Forums

Noticed my Discus laid eggs again, but they got fuzzy white stuff on them within a day. Water params are good, 0 ammonia, 0 nitrite, nitrate around 10 ppm. Temp's at 84°F, pH 6.8. Tank's a 75-gallon with sponge filters and driftwood. They're paired with Cardinal Tetras and Corydoras. Anyone know why this keeps happening? Fed them beef heart and brine shrimp mix twice daily.

Had the same issue last month. Tried adding methylene blue to the water, but it didn't cut it. My tank's a 55-gallon with sand substrate and Java Ferns. Temp's at 83°F. Maybe it's the parents not fanning the eggs enough? Mine seem kinda lazy.

Fungus usually hits if the eggs aren't fertile or the water's got organic buildup. You gotta siphon the tank bottom more often, especially with beef heart in the diet. My 90-gallon's bare-bottom with a canister filter, and I do 50% water changes every other day. Also, try lowering the pH to 6.5—Discus eggs hatch better in softer water.

Fade wrote: ↑Sat Aug 02, 2025 9:13 am Had the same issue last month. Tried adding methylene blue to the water, but it didn't cut it. My tank's a 55-gallon with sand substrate and Java Ferns. Temp's at 83°F. Maybe it's the parents not fanning the eggs enough? Mine seem kinda lazy.

Methylene blue's hit or miss. I've had better luck with hydrogen peroxide dips—1 ml per gallon for 10 minutes. Just gotta be careful with the dosage. My pair's in a 60-gallon with RO water, TDS around 100. Eggs hatch fine now.

Parents might be stressed. What's the lighting like? Too much brightness can freak them out. I run LED's at 30% for 8 hours in my 125-gallon. Also, check for stray currents—Discus hate strong flow near the eggs. Mine spawn on a flat slate tile away from the filter output.

Thanks for the tips, everyone. Gonna try the hydrogen peroxide dip and up the water changes. Lights are on a dimmer, but I'll double-check the flow. Appreciate it!

Egg fungus is often bacterial. Test for dissolved organics with a TDS meter. My 40-gallon breeder has a TDS of 80, and I add Indian Almond Leaves. Spawning cone's in a quiet corner. Eggs rarely fungus now.

My Discus never got eggs to hatch. Tank's 50-gallon with a HOB filter. Maybe I need a bigger tank. Water's at 82°F. They eat flakes and bloodworms.

Yo, my dude had this prob too. He cranked the heat to 86°F and bam, no more fuzz. Dunno if it's luck or what. His tank's a 65-gallon with a buncha plants. Feeds 'em frozen stuff mostly.

jolvy wrote: ↑Sat Aug 02, 2025 4:03 pm Egg fungus is often bacterial. Test for dissolved organics with a TDS meter. My 40-gallon breeder has a TDS of 80, and I add Indian Almond Leaves. Spawning cone's in a quiet corner. Eggs rarely fungus now.

Yep, TDS is key. Also, if the parents are young, they might not have the hang of it yet. My first pair took three tries before they got it right. Now they're champs in my 120-gallon with a sump.