I like visitherm stealth, they automatically turn off when taken out of water and they are shatter resistant, they dont take away from your tank either (they're all black). I have 2x250watt heaters on my 65gallon tank, I don't remember what wattage per gallon is used,I think it was like 5watts at least for the heater per gallon. I don't really know, it doesn't seem efficient to use 4 heaters on a large tank, just trying to bump the post. I have used ebo-jager too.