Depending on the breed, they can destroy even the hardiest of aquarium designs. Mine is one of those. Most of the filters that are sold by pet stores, are not adequate for a turtle. Unless you want to clean the tank weekly, which can be a pain, you need a better filter system. I went for a powerful outdoor pond filter that can handle 1000 gallons. because it's so powerful, it keeps the tank super clean and I only have to do a filter clean every three months or so. It also creates a great water flow that the turtle likes and any fish in the tank like to play in.