Pet Forum / Aquaria / Marine Reef / November 2006

ALSO get a therometer, even though the heaters have a setting on top, make
sure when you set the heater at 74degrees that is actually 74 degrees. (
adjust accordingly)

Try 50W heater next time.
It will be enough for such a small tank!

If you are afraid 50W will not be enough
(like because you keep thermostat really low
in your fish room) than get 2 heaters, 50W each
instead of one 75W or 100W.

If one 50W fails stuck or open the second will
work OK and turns itself on/off as needed,
minimalizing temperature difference effects...

That's about twice what you need. Fenner recommends about 3 watts per gallon;
100 watts should be sufficient. When you have too large a heater, it comes on
frequently; smaller ones come on and stay on for a while ('cause they heat the
water more slowly). This more frequent cycling and more rapid heating of the
water stresses the fish and leads to thermostat failure with mechanical thermostats.

While we're on the topic of thermostats, I would go with an electronic
thermostat. I'm told that they're more reliable than mechanical and, when they
break, they usually fail in "off" mode. My old Supreme Heetmasters used to
require replacement of the mechanical thermostat every few years; I've had no
trouble from the Tronic brand replacements I bought over 10 years ago.

I'm also a firm believer in dividing the heating load. If you have two heaters
and only one fails, there's a much better chance that the tank will survive
until you notice the problem. With your tank, I would go with two 50 watt heaters.

George Patterson
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