:unsure: Hey I'm wondering why the different wattage in a range of heaters. Do you need a certain size for a certain size tank??

My guess is you can't use a 50w in a 500g tank is it still ok to use a 300w in a 30g tank, I would guess so, anyway just for the sake of curiousity :huh:

it depends greatly on the outside temp of the tank and the temp you want to hold. if you live in a cold climate and are trying to maintain a high temp then you may want to run between 3 and 5 watts per gallon. if you live in a hotter climate then you could probably get away with 2-3 watts a gallon. and instead of running one big heater, split the wattage between 2 smaller heaters. that way if one breaks you still have some source of heat until the faulty one can be replaced. also if one goes crazy and stays on it is not capable of overheating your tank all by itself.:)

Good point cich, I myself only buy 300watt heaters because sooner or later they end up in my tanks :D