One 50 Watt Heater or Two 25 Watt Heaters?

[no_fin_nipping]

I'd go with the single heater. In a large tank, like a 125 gallon, I could see the benefit of 2 heaters for better heat distribution... If you are concerned about heat distribution, the next question is how is your circulation. If you have adequate circulation, there's no need for two heaters.
Personally, I have one heater per tank, and 4 tanks range from 20 long to 37 gallons. I have an old hang on the back 50 watt as a "spare". I keep my house cold in the winter. 65 for morning showers. 60 during the day and evening. 58 when we sleep. My 37 has a 200 watt, which is working hard to maintain 73 in the winter. I doubt the 50 could maintain 68 in that tank a month from now when the house is really cold.
I have two Rena Cal Excel and one Visi-Therm Stealth and one Visi-Therm Stealth. All have been running fine for over 2 years. When I used to use hang on the back filters, I had some that lasted 10-12 years. Then they started going bad 5 years ago. Their replacements were hang on the back style. Most got stuck "on" within 2-3 years.
They simple don't make them like they used to. I'm hoping my current heaters go a few more years, they cost 2-3x what the previous heaters did.

 

[NinjaPirate]

Nfn does bring up one interesting point, and one that I forgot some people may have to consider. The 5W/G rule with heaters are only good for pushing the tank temp so far above the ambient room temp. So if you live in a cold area and leave your room temperature cold/very cold, you may need a larger heater to maintain a tropical temp. Generally, if the ambient room temp is in the 65F+ range, the 5W/G will work for you. but if you're needing to increase the tank temp by ~15F or more, you may want a larger heater so that it doesn't have to work as hard.

 

[ewurm]

It's always better to split the wattage and buy two, in case one fails. And buy more wattage than you need.

 

[maryalice81403]

Thanks!

Sounds like a pretty even split between the votes for 1 or 2 heaters. Some great information though, especially about the need for more watts for a colder room. I'll keep that in mind. Thanks for responding!