Tropical fish (freshwater) question?
September 8th, 2010 | 
Author: I know most tropical freshwater fish prefer water from I believe 72 to 82 degrees farenheit. But is there a certain temp they do better at? What should my aquarium be at for the majority of these fish?
Posted in Tropical Fish Answers | Tags: aquarium, farenheit, freshwater fish, Tropical freshwater fish
There are certain fish, like Discus and cardinal tetras, that flourish at the higher ends – in the 80′s. Others, some catfish, livebearers, etc., are better at the mid-low 70′s.
It really depends on your individual fish. Staying in the 75-78 range is typically easiest. The warmer the water, the faster their metabolism and more they’ll eat. The cooler, the more lethargic and inactive they become.
A neat trick: in cases of ich illness, slowly increase the temp to about 85. That’ll speed up the metabolism and life cycle of the parasite.
Optimum temperature varies from fish to fish, but for a general community tank people usually set it to around 78f. Just check the minimum and maximum temperature recommended for each fish, as if the water is too warm for them for any length of time it can reduce lifespan considerably.
I keep my community tank at 78 degrees F. I’ll warm it up to 80 or 82 if I’m treating a disease.
72 seems too cold for anything other than goldfish.
Because fish come from all sorts of different places they do prefer different temps. Some "tropcial" fish can live quite happily down at 68F, other must be kept up over 80F.
So you need to look up the fish that you want to keep, see what their temperature range is, and set up the tank so it’s in the middle of those ranges.
77F is a good average temp for the common aquarium fish. But if your were going to keep Zebra danios, White Cloud Minnows and Hillstream loaches you could set the temp down around 70F. But Discus prefer the temp up around 85F. So obviously trying to keep those species together is not a good idea.
77F is the top temp for some species, but the lower limit for others, thats what makes if a good average for the common fish.
Ian