Originally Posted by calfishguy
I myself won't call 80° an extreme difference from 78 but that's just me. I also checked three websites and two of my books and I believe 78 is fine for rams. Just to confirm something though do you know if there are references for the info in the fish profiles.
Rams prefer 76-78 but will do absolutely fine in 80 degree water granted you accurately acclimate them to the temperature. You should not expect to see any decrease in life span by keeping them at that temperature.
Profiles are based on "general" fish information, and do not accurately describe every fish. You should use these as a general rule of thumb when picking out new fish, but it's perfectly fine to change the parameters.
I have mixed parameters for a lot of fish and have had no issues doing so. Granted I would never severely alter their parameters, but small changes should have no ill effect. If you were keeping a cool water fish (IE 72 recommended and you kept them at 80) then you would see a decrease in their life span.
Hope this helps.