Really? Well, like I said, my visitherm was the only one that broke, though I don't know it it was just from me moving stuff around (the heater is in the sump next to the skimmer, skimmer pump, tank drain, etc).
Oh, and I was mistaken, I actually replaced the busted visitherm with
"All Glass Aquarium Submersible Aquarium Heater" it says "NEW! Breakthrough Technology!" I think it was on sale when I discovered the busted visitherm in my tank (just before my flight home at Christmas!) It says "Made in Italy by Hydor" on the back of the box.
It seems to work OK. Like most heaters, even if I set it at 77, the temp setting is off a few degrees and required manual tweaking ... which takes quite some time considering how long it takes to heat that much water to some stable temp...and accounting for the lights being on or off!
Do you guys thing a SINGLE 300W heater is better? Or two 150s?
Cost aside, I was thinking that with two 150s, if one failed, you still had one working overtime to keep the water from going dead cold. And if one goes on the fritz and "gets stuck on" then the other's thermostat will shut itself off and you have a single 150W heater constantly on. (Assuming you have such a volume of water that a 300W would be the correct size). I'm sure the two heaters might make each other turn on and off, but if you spaced them far enough apart, that might not be such a huge deal.
Just a thought.
V