Water temp changes- does it hurt the fish

[gmoses]

So with winter finally hitting us I wanted to take down the temperature in some of my tanks from 81 to 76. I realize 81 is high i thought i had it set to 78 but recently when i did a water change i realized the temp was around 81. Any way i want to lower the heater to 76. Is there any problem with just lowering the heater and letting it fall 5 degrees on it own. Will the fish be harmed or will they have a behavioral change from such a quick change in temps? Will they be less active?

[Pete]

5f won't be a problem. Some people do water changes using water with a higher difference to trigger spawning.

[Dylz]

i would just turn it down to your desired temp. should take several hours for the temp to drop depending on the temp in the room. i dont foresee your fish being harmed at all. i dont even use heaters because my room stays 77-79 degrees.

[Longstocking]

Depends on the fish but in general... yes it will be okay.

[Ck986]

I think if it's a large swing that lasts for less than a day or two you should be fine. My main tank dropped from 78 to 62 last year due to a power outage that lasted almost two days. When the power went on the temp came back up in over 6 hours. All my fish were fine. Even my fry tanks survived with out any casualties.

[cracks]

I think if it's a large swing that lasts for less than a day or two you should be fine. My main tank dropped from 78 to 62 last year due to a power outage that lasted almost two days. When the power went on the temp came back up in over 6 hours. All my fish were fine. Even my fry tanks survived with out any casualties.

Same thing. Was out of power for 3 days. The temps dropped to about 52 and all came back up to 78 withing 8 hours. Only lost 3 fry. I was scared I was gonna lose all.

[mnjason]

i do 50% water change every week i have my tanks set 76-78 and add cooler water when filling them back up.in the summer i run straight cold water and 9 times out of 10 they spawn.but what works for me may not work for you or your fish