Thus, the larger the volume of water, the less frequently it needs to be changed. Obviously, stocking density will dramatically affect this. The more turtles in the cage, the more frequently the water must be changed even with very large volumes. Feeding frequency also affects water quality. The more often one feeds, the more often one cleans.
Some foods foul the water quickly.
If the turtles are fed in their enclosure, the water should be changed within 12 hours of feeding. The water can be kept cleaner by feeding in a separate container. Initially, some turtles are reluctant to feed in the separate container but can be acclimated to this over time. When doing a full water change, it is important to scrub and rinse the cage well to remove residual bacterial growth on all sides. Abrupt changes in water temperature can kill turtles so make sure the water temperature after cleaning is similar to what it was prior to cleaning.