Whats the Difference between Fresh & Coldwater fish?

[excuzzzeme]

^Yeah. Most tropical fish like a temperature of 78* F, while most coldwater fish like a temperature of 70-72 degrees. (Room temperature without a chiller)

I think this is a pretty good explanation.

freshwater tropicals = 78º and up (heater advised)
Freshwater coldwater below 78º (room temperature - no heater required)

Some coldwater fish can withstand water temps in the high 30's.

 

[Notophthalmus]

Just a point- 'coldwater' means different things to different people. Many folks use it to describe all non-tropical fish, while others reserve it for fish such as trout and sculpin, which need below-room-temp water and generally cannot be kept in a home aquarium without a chiller.

 

[Slappy*McFish]

Generally when I think of coldwater fish, Koi and Goldfish come to mind...especially when it pertains to freshwater fish keeping.

Coldwater marine tanks do exist, as well.

 

[Coler]

Coldwater can be salt/freshwater.

Freshwater can be tropical/coldwater.

Saltwater cannot be freshwater.

Freshwater cannot be Saltwater.

Brackish....ummmm...that's for real wierdos who just can't make their minds up