heaters failing, mot one, not 2 but 3

[Myka]

Originally Posted by KevinK

so I both 3 marine land visi-therm heaters, 300W each to heat 100 gallon.

all fine, all 3 put at its max, and conected to my controller, that wil put all one at once at the set point of my controller (79 deg.)

I have several Visi-Therm heaters with no issues, these along with the Eheim-made Jagers have been really reliable for me for years. Not saying the heaters aren't faulty, but three heaters...? I don't think it is the heaters problem. I think maybe your controller has the issue and may be frying the heaters or simply not running them properly. Which controller are you using? Is it capable of running 900 watts of heaters? Is it capable of running multiple heaters? Some won't run that much power draw or run multiple heaters. When you checked if the heaters were warm did you try plugging them directly into a wall outlet?

On a different note, I think you are setting yourself up for disaster. First, what is the room temperature? Do you have more plumbing than usual (say plumbed to basement) or something like that? I'm wondering why you need 900 watts of heaters, that is exorbitantly huge for a 100 gallon system. I have a 150 watt heater on my 90 gallon tank that I just installed a couple days ago because the temp is dropping a bit too low at night this time of year (it hasn't had a heater on it since spring).

Secondly, when heaters fail they usually quit working, however it is also very common for thermostats to fail which often means the heater will be stuck ON. Depending on your room temperature, a single 300 watt heater on 100 gallons of water could very well do a great job of cooking your tank and all it inhabitants. I lost two full tanks to this over a decade ago, and have since learned to use multiple small heaters so that if one gets stuck on it won't be powerful enough to cook the tank.

Third, if your controller ever fails your three 300 watt heaters will surely cook the tank very quickly. I think you would be better off setting each heater to say 84 degrees (something your reef should be able to withstand). Then if the controller fails the tank will only heat to 84.

Redundancy is the best insurance we can get for our tanks!