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I've been doing weekly 50% water changes on my 75-gallon Discus tank, but they've been acting stressed lately. Water params are good, 0 ammonia, 0 nitrite, 5 nitrate. Temp is steady at 84°F with a Fluval heater. Could I be messing something up during changes?

Cloudy wrote: ↑Tue Aug 19, 2025 8:35 am I've been doing weekly 50% water changes on my 75-gallon Discus tank, but they've been acting stressed lately. Water params are good, 0 ammonia, 0 nitrite, 5 nitrate. Temp is steady at 84°F with a Fluval heater. Could I be messing something up during changes?

How's your water change routine? If you're pouring too fast or not matching temp/pH closely, that'll freak them out. I use a Python to refill slowly over 20 mins, and I always pre-treat with Seachem Prime.

Yo, same issue here. My guys dart around like crazy after changes. I've got a bare bottom tank with sponge filters, so it's not like there's much to mess with. Maybe it's the tap water? I don't test for chloramines, just chlorine.

Chloramines are a big deal if your municipality uses them. They don't off-gas like chlorine. Also, check your TDS—if it's swinging more than 50 ppm between changes, that's rough on them. I aim for 150–200 ppm with RO water and remineralizer.

Lol, my Discus used to give me the side-eye after changes. Turns out I was being lazy with temp matching. Now I use a digital thermometer to check both buckets, and they're way more chill. Also, try dimming the lights during changes—sketchy vibes freak them out.

Sprig wrote: ↑Tue Aug 19, 2025 12:26 pm Chloramines are a big deal if your municipality uses them. They don't off-gas like chlorine. Also, check your TDS—if it's swinging more than 50 ppm between changes, that's rough on them. I aim for 150–200 ppm with RO water and remineralizer.

Exactly. TDS swings are brutal. I log mine before/after changes. Also, Cloudy, what's your substrate? Deep sand can trap gunk that gets stirred up during changes.

Are you vacuuming the substrate aggressively? I've seen folks rip up biofilm and crash their cycle mid-change. Stick to light surface cleaning unless you've got detritus buildup.

This thread's a lifesaver. I've been rushing changes in my 55-gallon, and my Discus hide for hours after. Gonna try the slow refill and temp match thing. Thanks, y'all.

Dory wrote: ↑Tue Aug 19, 2025 10:17 am

Cloudy wrote: ↑Tue Aug 19, 2025 8:35 am I've been doing weekly 50% water changes on my 75-gallon Discus tank, but they've been acting stressed lately. Water params are good, 0 ammonia, 0 nitrite, 5 nitrate. Temp is steady at 84°F with a Fluval heater. Could I be messing something up during changes?

How's your water change routine? If you're pouring too fast or not matching temp/pH closely, that'll freak them out. I use a Python to refill slowly over 20 mins, and I always pre-treat with Seachem Prime.

Thanks! I'll grab a Python and slow it down. Didn't realize speed mattered that much.

bruh, my tap's pH is 8.2 but my tank sits at 6.8. i cut it with RO now, no more freakouts. also, prime's a must, no cap.