Re: $$ to run heater

> From: Miles Morrissey <mmorriss at sophia_smith.edu>
> Date: Wed, 12 Feb 1997 09:26:17 -0500 (EST)
> Subject: $$ to run heater
> I was wondering if anyone had a general rule of thumb about how many 
> hours per day a heater is on.  In order to calculate how much $$ I'm 
> spending to run various instruments in my aquarium I need to know how 
> long they're running.  This calculation is easy with lights and pumps 
> but I can only guess as to how long the heater runs.  Specifically, in 
> my 50G tank which I keep at 75 degrees in a 70 degree room, I'm guessing 
> that the heater is on 4 hours / day.  Does this sound conservative or 
> liberal?  Given the number of variables to consider I imagine this would 
> be a tough one to nail down but what are people's opinions?

This is impossible to say -- it depends on too many variables: temp 
difference between the  room temp and tank temp, size of the tank and 
wattage of the heater. Thus, the same heaterr may on be 12 hrs per 
day one day and 6 hrs the next day - unless you keep the room temp 

The best thing, imho, would be to find what wattege you need to keep 
the tank close to the desired temp with the heater on constantly. For 
example, I found that a 100W heater will be always on for my 175 litre 
tank to maintain 5-7 deg.C room-tank difference. 


Jan Fidrmuc

CentER for Economic Research
Tilburg University
P.O.Box 90153
5000 LE Tilburg, 
The Netherlands

Phone: +31-13-466-2678, +31-13-466-8221
Fax: +31-13-466-3066
Email: J.Fidrmuc at KUB_NL