I love my ViaAqua 200W Titanium heater, I too have a 55 gallon tank. keeps the sensor away from the heater for what seems like a very accurate reading and it stands out a little less on the black background then the glass heaters I've used.
55 Gallon tank heater placement question : Aquariums - Reddit
You should consider the cost of keeping a large aquarium running 24/7. You will need a heater and a filter running every single day of the year. Because Oscars are tropical fish the aquarium water must be kept warm at all times. A 55-gallon aquarium is going to require a minimum of 200 W of heating that must be switched on all the time (imagine leaving the house lights on 24/7 in two or three rooms of your house). Filters won't use as much power, but they will still need to be kept running at all times. Many of us have water meters and therefore pay for what you use. The bigger the tank, the bigger the water change each week. Then you've got your food on top of all this, plus any medication that may be needed. The biggest mistake you can make is thinking that an aquarium doesn't cost anything to run. Big aquariums can not only increase your electric bill each year but also the water bill at the same time.
Cichlid-Forum • 250w heater in 55 gallon tank
I had 2 glass finnex heaters shatter in 2013, then the other 2 glass Finnex heaters died in 2014 (all 4 bought Between November 2012 through January 2013), so I swapped to Eheim Jagers as each of those Finnex heaters died. The last of those Ehiem Jagers were replaced in December 2015, because 2 died in the off position & 1 stuck in the on position. The one that stuck in the on position cooked an entire 54 gallon tank of 2-3 year old fish that were worth a minimum of $400 when bought as babies, so I happily pulled the last functioning Ehiem Jager out of the tank, cut the cord & trashed it. It might have worked for years, & was in a 55 gallon guppy tank, so no huge loss if it failed, but why risk it? I am currently running Hydor inline heaters on 2 tanks & Aqueon Pro heaters on 4 tanks (no glass to potentially break).
I had a 200 watt heater in my 55 gallon tank