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What's the ideal water depth for a breeding tank? I've got a 40-gallon setup with a pair of Discus, sand substrate, and a sponge filter. They're about 4 inches long, and I'm aiming to encourage spawning. Heard conflicting advice on whether shallow or deep water works better.

I keep mine at around 12 inches. Seems to work fine with my setup, which is similar to yours. Sand bottom, sponge filter, and a few Java ferns. They spawned last month without issues.

12 inches is a good starting point, but it depends on the fish's comfort. My pair prefers slightly deeper water, about 15 inches. They're in a 55-gallon with driftwood and floating plants. Maybe try adjusting gradually and see how they react?

Limey wrote: ↑Sun Aug 17, 2025 10:19 am 12 inches is a good starting point, but it depends on the fish's comfort. My pair prefers slightly deeper water, about 15 inches. They're in a 55-gallon with driftwood and floating plants. Maybe try adjusting gradually and see how they react?

Yep, gotta watch their behavior. Mine freaked out when I went too shallow, so I bumped it back up. Now they're chill at 14 inches with a bare bottom tank and a canister filter.

I've had success with 10-12 inches in a 30-gallon. Used a mix of sand and slate, plus a couple of Anubias. The key is keeping the water super clean, like daily 10% changes. They're picky about that when breeding.

Depth isn't the only factor. Water quality and temperature matter just as much. I keep mine at 84°F, pH around 6.5, and the depth at 13 inches. They've spawned three times this year in a 40-gallon with a HOB filter.

Thanks for the tips, everyone. I'll try lowering the water to 12 inches and see how they respond. Appreciate the help!

giggle wrote: ↑Sun Aug 17, 2025 2:20 pm Thanks for the tips, everyone. I'll try lowering the water to 12 inches and see how they respond. Appreciate the help!

No problem! Let us know how it goes. Sometimes it's just trial and error with these guys.

Yeah, Discus can be finicky. Mine took a few tries before they got it right. Now they're laying eggs every other week. Just keep the water pristine and don't mess with 'em too much.

Agreed. Less interference is better once they start showing breeding behavior. Mine don't like it when I hover too much.