|zombiefish610 ||10-16-2009 07:16 PM |
Hope this helps.
Heaters are rated by how many watts of electricity they consume. "Watt" is right for your tank? Well, a useful rule of thumb is to allow about 5 watts per gallon of water in an average room where the desired temperature of the tank is about equal to or less than 10 degrees warmer than the room. If you are attempting to run an aquarium at, say, 80 degrees while room temperatures dip to 50 or 55 degrees, then it might be better to increase that recommendation to 10 watts of heater per gallon of water. (Frankly, I have found the 5 watts per gallon rule to be extremely conservative. It would only be in an extreme situation where a larger heater would be required.) It is always a good idea to have a heater that is rated as adequate or slightly more than adequate, as compared to a marginally rated heater. A marginally rated heater may have to run constantly to barely maintain the desired temperature, and would have no reserve capacity should the room chill down a little lower than expected (such as when that furnace decides to fail on a cold winter morning). A heater with adequate capacity and a little reserve capacity will not have to cycle nearly as often to maintain the desired temperature, and will thus enjoy a longer service life. It will also be able to handle that rare and always unexpected demand for more heating capacity should room heat fail.
Some people recommend dividing the wattage between two heaters. For example, if you were running a 20 gallon tank and, using the 5 watts per gallon recommendation, decided you needed a 100 watt heater, some would recommend that you run two 50 watt heaters rather than a single 100 watt heater. They reason that in case one heater fails, the other would be able to pick up at least part of the slack and not let tank temperatures plunge too drastically before you could catch the error and you could secure a replacement heater. (People living in very cold climates should ALWAYS keep a spare heater or two on hand, just to handle potentially disastrous emergencies such as this.
A spare heater on the closet shelf is very cheap insurance if your tank full of expensive fish should suddenly be endangered by heater failure on some cold winter Sunday morning, when you might not be able to secure a replacement right away.) By dividing the heaters into two heaters, the reasoning continues, it also helps prevent the heart-breaking experience of a heater thermostat sticking in the "on" position, and thus cooking your fish. If you are in this hobby long enough, sooner or later you will either meet someone who has had that experience, or (heaven forbid) you might go through it yourself. Dividing the wattage between two heaters seems to make sense.