what size heater for my tank?

[cockroach]

my own measurement i use is 1 watt per litre. so i would say 200 is fine. but more is always better as the heater will work less if its stronger

 

[vfc]

I have a single 200W Stealth on my 150G. Temp is very stable. I did a 50% water change last night with slightly colder water. Tank temp dipped to 77.5 I checked the temp this morning at 7AM, it's back to 79.

 

[vfc]

I disagree with this statement; "more is always better as the heater will work less if its stronger".

Electronic devices most often fail when first turned on rather than while they are running. Think about when a light bulb fails. It almost always fails when you first turn it on.

Same is true for a heater. A low wattage heater that is on most of the day will last longer than a high wattage one that constantly cycles on and off. Higher wattage means higher electric current flow; which is hard on bi-metal contacts or solid state switches.

 

[Bud8Fan]

I disagree with this statement; "more is always better as the heater will work less if its stronger".

Electronic devices most often fail when first turned on rather than while they are running. Think about when a light bulb fails. It almost always fails when you first turn it on.

Same is true for a heater. A low wattage heater that is on most of the day will last longer than a high wattage one that constantly cycles on and off. Higher wattage means higher electric current flow; which is hard on bi-metal contacts or solid state switches.

I agree. Well said vfc.

I've posted this before but use this handy calculator to find your optimum wattage based on tank size, room temp, water temp and glass or acrylic. Acrylic will require much less wattage as it insulates better.

http://boonedocks.net/fishtank/ftweb.php