It is used to regulate the temperature of the water
Cuz it is used to the small tank
yes because there used to the tank and they become nocturnal
A filter...
I wouldn't recommend using an all-glass tank for reptiles. Any heat source, and thermostat you use, would have to work 'overtime' to maintain the temperature within the tank. this is because 90 percent of the heat generated would simply escape through the glass.
It will either have to get used to it or die.
It would depend on the size of the tank, and what comes with it.
How long does it take for a oscar to get used to a new tank
I would not advise it.
That all depends on how warm the area is where you wish to keep the tank. If the tank will need a heater/thermostat unit then that would be the main physical limiting factor. The unit must go completely under water. I would remind you however that the smaller the tank the harder it is to keep fish in it successfully. The basic rule for keeping fish is 1 gal (4.25ltrs) of water is needed for 1" (2.5cm) of fish.
Some commonly used fish pet supplies are aquarium salt, filters, and lighting. The most commonly used fish pet supplies are fish food and a fish tank.
The tank you have described is extremely small and should not be used to house any fish. 1 gallon is not enough space for a fish to swim around, and it will most likely have a very short life if kept in this tank
I have an Oscar Cichlid in the same tank as mine and I also used to have it with guppy's.