Who Gives A Fish Forums

How often do you guys change water for your Discus? I've got a 75 gallon tank with 6 adults, running a Fluval FX6, and I'm doing 50% twice a week. They seem happy, but I'm wondering if I can cut it back to once a week without stressing them out.

I do 30% weekly on my 55 gallon, but my fish are still juveniles. They're growing fine, but I've heard adults can handle less frequent changes. Maybe try scaling back slowly and see how they react?

darksage wrote: ↑Thu Aug 07, 2025 4:21 pm How often do you guys change water for your Discus? I've got a 75 gallon tank with 6 adults, running a Fluval FX6, and I'm doing 50% twice a week. They seem happy, but I'm wondering if I can cut it back to once a week without stressing them out.

With a tank that size and a solid filter, you could probably drop to 50% weekly if your nitrates stay under 20 ppm. Test before and after changes for a few weeks to be safe. What's your substrate and feeding routine like? That'll affect waste buildup.

Mine are in a 90 gallon with sand substrate and driftwood. I change 40% weekly, but I've got a bunch of plants helping with nitrates. If your tank's bare-bottom, you might need to stick with more frequent changes.

tyrny wrote: ↑Thu Aug 07, 2025 4:55 pm I do 30% weekly on my 55 gallon, but my fish are still juveniles. They're growing fine, but I've heard adults can handle less frequent changes. Maybe try scaling back slowly and see how they react?

Yep, adults are more forgiving. I've got a 75 like OP, and I do 40% weekly with no issues. Key is consistency—if you're gonna cut back, keep the schedule tight. Also, what temp are you running? Warmer water means faster metabolism, so more waste.

Thanks for the input, everyone. I'll test nitrates more closely and maybe try scaling back to once a week. Temp's at 84°F, and I feed them frozen beef heart mix twice daily. Substrate is bare-bottom for easy cleaning.

darksage wrote: ↑Thu Aug 07, 2025 10:37 pm Thanks for the input, everyone. I'll test nitrates more closely and maybe try scaling back to once a week. Temp's at 84°F, and I feed them frozen beef heart mix twice daily. Substrate is bare-bottom for easy cleaning.

At that temp and feeding schedule, I'd keep an eye on ammonia spikes if you reduce changes. Beef heart's messy stuff. Maybe swap one feeding to pellets to cut waste? Just a thought.

Yeah, beef heart's gonna gunk things up fast. I switched to Hikari Discus Bio-Gold and my water's way clearer. Still toss in frozen bloodworms as a treat, but not daily.

If you're set on beef heart, try rinsing it before feeding. I soak mine in tank water for a sec to wash off excess gunk. Cuts down on the cloudiness.