heating help

[rED O]

I was not sure where to post it so I will post it here


Boxing day, I was at big als in the morning to pick up two 300 watt heaters for my 500 gallon tank. I thought 600 watts would be fine. But since I bought them I never looked at them, but I did notice they were a little on the small size. On the box it says up to 75 gallons up to 75 gallons for a 300 watt heater? I thought 300 watts was 300 watts? up to 75 gallons? The brand is marineland.
http://www.aquatichouse.com/Pumps_files/heaters.asp
will I be fine or is this a crappy heater? I have always used ebo jager but they do not make a 300 watt.

any help?

 

[Cholly]

I don't have to heat anything that big. Yet. But at 4-5 watts per gallon, wouldn't you need at least 2,000 watts? Or does the requirement go down somewhat as you go up in size? At 600 watts, you're barely over 1 watt. I use 200 watt heaters in my 55's.