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, sand substrate, and a Fluval FX6. Been doing 30% twice a week but they still seem stressed after changes. Temp's at 84F, pH 6.8, 0 ammonia, 0 nitrite, 10 nitrate. Wondering if I'm overdoing it or missing something.

Are you matching temp and pH exactly? My 55-gallon with sponge filters and blackwater extract needs 30% weekly, but I drip-acclimate the new water over an hour. Discus are less jumpy when the new water's identical to the old.

Bless y'all for the tips! My poor babies in their 65-gallon with LED lights and almond leaves were sulking after changes. Gonna try Lardy's 15% every 3 days and slow-drip like Blossp said. Fingers crossed they perk up.

Timing matters too. I change water in my 120-gallon at night when the Discus are calmer. Bare bottom, Tidal 110 filter, and aged tap water. 25% weekly, but I add StressGuard afterward. Zero stress marks since I switched.

Tonito wrote: ↑Wed Jul 16, 2025 9:47 am Timing matters too. I change water in my 120-gallon at night when the Discus are calmer. Bare bottom, Tidal 110 filter, and aged tap water. 25% weekly, but I add StressGuard afterward. Zero stress marks since I switched.

Smart move. I've noticed mine in a 75-gallon with RO water and Java ferns react better to evening changes. Also, double-check your dechlorinator dose—overdoing it can weird them out.

Y'all making this too complicated. My 50-gallon with hob filter and no plants gets 50% weekly, straight from the tap with Prime. Discus don't care as long as the food's good. Beef heart twice a day, and they're beefy themselves.

Rider's got guts, but I wouldn't risk tap swings. My 180-gallon with sump and UV sterilizer gets 40% weekly, but I pre-mix in a brute can for 24 hours. Discus are spawning monthly, so something's working. Maybe try a holding tank for new water?

Thanks for all the ideas! Gonna test smaller changes and drip methods. Appreciate the help.