Heater died overnight in the grow-out tank, 24C by morning. How worried should I be?

Woke up to the discus grow-out at 24C instead of 29. Heater had just quit. Swapped it, tank is back up to 27 and climbing slowly. Everyone is eating a bit shy this morning. I'm skipping the big water change today so I don't stress them more. Anyone had a drop like this and did they get sick after?

💬 6

6 comments

B BrackishBabe Oct 15, 2026 · 2:27 PM

24C isn't a disaster for adult discus, it's the swing that hurts. bringing it up slowly like you are is right. i'd keep the lights low today and watch for clamped fins or stringy poop over the next week.

PP Planted Pete Oct 15, 2026 · 2:29 PM

also worth a thermometer on the opposite end of the tank next time. mine caught a dead heater once because the back read way off from the front.

F& Fin & Fry Hatchery Oct 15, 2026 · 2:41 PM

good call pete. i run a cheap probe thermometer at each end of my discus rack too. dan, if they're still shy tomorrow add a little extra feeding of something they love, thawed bloodworm usually gets them back on food.

DD Discus Dan Oct 15, 2026 · 2:45 PM

thanks both. will put a second thermometer on the far end tonight. they took a few pellets this afternoon so that's a good sign, still keeping the lights dim.

S ShrimpLord Oct 15, 2026 · 3:10 PM

dan if the dip was only 5C and they're picking at pellets already you're probably fine. i'd still hold off on any new fish or big food changes for a week or so.

MB Moss Boss Oct 15, 2026 · 8:02 PM

dan hope they're eating better today. a lot of heater failures like that pass with no issues if the recovery is slow.