Oscar cichlid backing!!, urgent?

im probably going to buy a tiger oscar in the future(1 month or so..), and my 55-gallon-tank is almost finished cycling with my 2 goldfish that i have for 5 months now, i also have a 6" common pleco within the 55, but i only have the stand, hood/lights, and the filter, but no heater, can oscars live okay near a 20 GALLON TANK HEATER?, my uncle gave me his 100-watt-heater because he has 2 goldfish, and a pleco as well, and he cant own the heater on in his tank.

does the heating system work until it warms the whole tank?, i dont deliberate there is a problem by putting a 100w heater in 55 gallons, the reservoir is in the living room, and the thermometer reads most of the time 73F.
if u reflect this heater wont do the job, please tell me why because im somewhat confused nearly this.
alsooo, what is the lowest temperature an oscar can survive?

Answers:    well i sure hope you are not planning on putting the oscar surrounded by with the other fishes, or by by other fishes! as long as the heater is eating the cart to the proper temperature and keeping it there i don't see why not. if it does the commission right the who cares what the box says. i had an oscar for plentiful years in a 55 gallon tank with a 20 gallon electric fire from when i used to have sharks. it works just fine. oscar was roughly speaking the size of a feeder goldfish when i got him, and the size of a football when he died.
a 100 w heater should be sufficient. Just set it to the temp you want preferebly around 73. Also remember that oscars grow unbelievably rapidly and will likely reach 10 + inches by one year outdated. a 55 gallon tank will not be large enough for this fish for his unharmed life. Make sure you are read to commit to purchasing a larger tank. 75 gallons or larger to house this guy
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