If you put a turtle in the fish tank some turtle care problems might appear:

- First of all a fish tank usually doesn't have a land are which is vital for the turtle.
- Fishes are tiny little pets that usually don't need a very high water level. But the turtles are bigger and have to swim easily. So the water level in a fish tank could be to low for a turtle.
- In the fish tank the filtration is usually inappropriate for a turtle so the water could get dirty very fast.
- If you put a turtle in a fish tank eventually he turtle will eat the fish.
- It's good for fishes to provide them with plenty of plants so they can swim around the or hide. But the turtles will surely eat all the plants in the tank.

The best way to keep fishes and turtles together is introducing the fishes in an environment specially setup for the turtle. By using this method you won't have any turtle care problems. So make a correct turtle tank setup and then and the fish. The turtles will eat the fish, but if you add at least 20 fishes they will probably survive for an year.

There are some advantages for having some fishes in the turtle tank:

- You'll never have to feed the fish. The usually eat left-over food so it won't be expensive to keep them.
- You can consider the fish in your turtle tank as some kind of water quality monitor. You can think that, if the fishes are healthy than the water in the turtle tank is quite acceptable.
- The fish in the turtle tank can become a good emergency food for your turtles.
- Most captive water turtles don't swim enough and don't get enough exercise. But with the fish in the tank they won't get bored anymore.

So it's not such a bad idea to keep a fish together with a turtle in a turtle water tank.