No. An Oscar needs a minimum of 75 gallons with an extra 20-30 gallons per each added Oscar. Oscars grow very large and are predatory. Please read up on them before you even think about getting one.
Jack Dempsey or Tiger Oscar
It depends on what size you have. You can have upto 1inch of fish for each U.S. gallon.
Depending on the size and age of your beardie. For a baby it can be housed in as small as a 10 gallon fish tank For an adult no less then a 40 gallon fish tank
Oscars are large and can be aggressive, their tank should provide at least 30 gallons of space per oscar, plus any space needed for any other fish. A minimum tank size of 40 gallons is recommended if you are keeping an Oscar. 10 gallon tanks are not for keeping large cichlids in. They are for keeping a few small tetras or other small fish. When it comes to Oscars and other similar fish, the minimum sized tank I would suggest is a 72" x 18" x 18" coupled up with a large power filter.
You could probably keep a school of a dozen Exodon Paradoxus in a 40 gallon, as long as they are kept well fed, with a riverine environment, and no other species of fish in the tank. Be prepared for a lot of work, but some enjoyable feeding sessions.
10 qts 1 gallon = 4 quarts 1 quart = 0.25 gallon
It never hurts to have a filter it will only improve your fish's chances of survival and decrease your need to clean.
I know that mine is a 40 gallon tank.
You can not grow fish to a tank. fish do not grow to the size of there tanks. if the tank is way to small they can die because there organs will keep growing but there skin will not grow. you could only have one in a 40 gallon tank. Good luck!!!! -- Most fish have indeterminate growth and that can be impacted by aquarium size, available food sources and other environmental variables. Keeping fish in an aquarium that is not suited for their size can stunt the growth of a fish. It can also overly stress a fish resulting in sickness and even death. As a general rule go by surface area to determine tank capacity. One inch of fish for each twelve square inches of surface area.
It never hurts to have a filter it will only improve your fish's chances of survival and decrease your need to clean.
As a very rough estimate, I would suggest 40 gallons!
I'm sorry but no turtle can live in a 2.5 gallon tank. You will need a least a 20 gallon tank and that is even iffy when they grow up I would say get a 30-40 gallon tank for one turtle.