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I've got a 75-gallon planted tank with six Discus, and I'm thinking about adding some Mollies. The Discus are about 4 inches, and the tank's been stable for months, 0 ammonia, 0 nitrite, 10 nitrate. Temp's at 84°F, pH 6.8. Anyone tried this combo before? Worried about the Mollies messing with the Discus' vibe.

Mollies prefer harder water and lower temps than Discus. Your setup's perfect for Discus, but Mollies might struggle long-term. I'd skip it unless you're ready to tweak params. Also, Mollies can be nippy, and Discus hate that stress.

mole wrote: ↑Fri Jul 04, 2025 12:34 pm Mollies prefer harder water and lower temps than Discus. Your setup's perfect for Discus, but Mollies might struggle long-term. I'd skip it unless you're ready to tweak params. Also, Mollies can be nippy, and Discus hate that stress.

Yep, Mollies need 78–82°F and higher pH. Your Discus won't thrive if you adjust for Mollies. Not worth the hassle, mate.

I kept Mollies with Discus years ago. The Mollies bred like crazy and crowded the tank. Had to rehome them after a few months. Stick to calm tankmates like Cardinals or Rams.

Thanks for the input, everyone. Sounds like it's a no-go. I'll look into Rams instead.

Good call! Rams are chill and love the same water. My Blue Rams hang out with my Discus all day, zero drama. Just make sure you've got plenty of hiding spots.

bowsar wrote: ↑Fri Jul 04, 2025 4:46 pm Good call! Rams are chill and love the same water. My Blue Rams hang out with my Discus all day, zero drama. Just make sure you've got plenty of hiding spots.

Second this. My Discus and Rams share a 90-gallon with driftwood and Java Fern. They're like besties, no kidding.

Mollies are sketchy with Discus. Had a buddy try it, and the Mollies kept stealing food. Discus are slow eaters, so they got outcompeted. Stick to peaceful dither fish.

If you're dead set on Mollies, maybe a species-only tank? But yeah, mixing them with Discus is asking for trouble. Different worlds, man.

My LFS told me Mollies and Discus could work, but reading this thread, I'm glad I didn't listen. Thanks for saving me the headache, y'all.