You should look to getting a heater to properly treat the fish, otherwise it may not get better
A heater can raise the temperature of a fish tank if needed
The water temperature varies with the type of fish, but normally it should be about 75 degrees. Most aquarium heaters do a good job of keeping the temperature at this point. If your fish get sick you may want to raise the temperature to about 82 degrees.
dont be stupid, you cant grow fish in your backyard you have no sea!! silly :D
Fish and reptiles both regulate their body temperature behaviorally by going to areas where the temperature fits their biochemical needs, eg. sunning on rocks to raise temperature, etc. Some fish and reptiles also hibernate when temperatures get too cold.
The best thing you can do to make your Oscar more active is to raise the temperature of the heater you have.
Should be around 22 - 28*C
100 degrees Celsius
So you can make sure the fish has a suitable temperature
Betta fish should be kept in water 72-82'F(22-28'C).
When checking the temperature of meat, fish or poultry, upon delivery you should insert the probe or the stem of the thermometer into the thickest part of the food.
Feeder fish should be cared for in the same way you would care for any other freshwater fish if you choose to keep and raise them
Storing fish for any real length of time would require freezing.