worried

I'm afraid of the tank temp. The guy who sold me my tank said that the water needs to be between 70-80 degrees. Today the room temp got up to 78 (average daily temp for fall in Texas), but the tank got up to 84.4 degrees. I'm not sure why the +6 degree delta, but I need to figure it out. I don't want to have to run my A/C to control the tank temp.

I found that the temp didn't change much from when the lights were on, and when they were off. I know the pump creates some heat, but the pump tank is the same temp as the main tank, and i would think if the pump were my problem, the difference would be greater than 1 degree. The main tank as 23.2 more gallons to help dissipate the heat, right? If someone know what i'm talking about, or just has a working knowledge of fluid dynamics, I would love to understand this better.


If the ambient temp is 78 degrees, and the tank is indoors with the lights on, is +6 degrees going to be average? does that mean i'm going to have to turn on my A/C and keep it 74 or below?? I'm not sure i want to do that!?!