Next, what kind of fish you decide to keep is another important criteria to consider. Turtles are sometimes notorious of eating just about anything that fits into their mouth. Other than healthy fish pellets, waste vegetable, or even crickets, part of their diet also includes fish. If you intend to ensure that your pet fish will get along well with your turtle, you should be careful in your selection to choose a compatible companion. Small sized fish like platy, guppy and neon tetra are definitely out of question and so does goldfish because they generate too much waste to the water and together with the turtle, heavily pollutes the water beyond control. My choice of a perfect fish and turtle combination would be selection of giant gourami, certain types of catfish and those cichlids which are not overly aggressive like the kribensis. Also to avoid are oscar fish because instead of your turtle eating the fish, they will end up getting injured from the provocative bite of your oscar.
Apart from what has been mentioned earlier, a turtle fish tank should also have a complete filtration system that can handle huge amount of waste generation. My recommendation is to get an external power filter and since you have a fairly huge size of fish, there won’t be much of a problem after all. If this requirement is not fulfilled, soon enough you will find that they water will turn murky and smelly due to heavy waste discharge. If possible, part of the tank accessories should also include an aeration system generated by air pump so that your turtle can enjoy an oxygen rich environment.
Turtles are also known to be a type of reptile that requires dry land for resting and shelter. Therefore your fish tank that you intend to keep your turtle should have a portion filled with sand or having a huge pile of large rocks that is higher than the water level. This way, your turtle will have a place to rest on especially when it gets tired of swimming. Either way, you could also consider getting the type of turtle ramp which is actually a plain plastic board that has a suction cup so that it can attach to the aquarium wall surface. Most people do not realize of this requirement and it’s a big mistake to let their young turtle swimming continuously with their fish, only to find a dead turtle after a few weeks with the death caused by exhaustion. I hope the information here will serve as a good guide for those wannabe who intend to setup a turtle living in a fish tank.