Heating a Tank vs outside tank temperature

[president89]

Hi, I moved into my new house, and what I used to heat my tanks with don't seem to hold the temperature at 80. I used to use 75 Jager heaters linked into a ranco thermostat. It seems that my Jagers can't keep my 15g tank up to 80 degrees. I busted out a 200w titanium heater and that did the job. The Jager heaters are definitely getting hot, and they are turning on as they should. The temperature in the room is between 60-65 degrees. Is there a formula to apply here to figure out wattage? I even used 2 75 Jagers and it wasn't raising the temperature. Maybe I wasn't patient enough?

 

[keithhays]

I have used this one before: http://boonedocks.net/fishtank/ftweb.php
5 watts a gallon is usually good though.

 

[keithhays]

btw, 60 degrees in a room seems a bit chilly, is it in the garage?

 

[president89]

btw, 60 degrees in a room seems a bit chilly, is it in the garage?

It's my basement. It's not quite 60, but i drop my heat in my whole house to 60 during the day when I'm not here. So the basement is the slowest part to heat up( it is heated).