Water chemistry is tricky for new yellow belly turtle owners to understand, and many of the same principles that keep a home aquarium running smoothly also help an aquatic turtle tank stay stable and healthy. The biggest principle that turtle owners need to know is the nitrogen cycle, which metabolizes toxic ammonia into a relatively harmless substance to maintain water clarity and prevent toxic buildup. There are a number of chemical additives and extra substrates that help maintain water quality, some of which can become part of the daily care routine or weekly maintenance.
The nitrogen cycle starts with a colony of beneficial bacteria that lives in the filter of the tank. A new tank lacks these bacteria, but anyone can jump-start their colony by purchasing a bacterial supplement available at any pet store. A new tank will be unstable and experience bad water quality more often, while older tanks have an established bacterial cycle and will remain more stable. For this reason, it is important to change the water in a new turtle tank more frequently.
Additionally, owners should have an ammonia detoxifier on hand to quickly treat toxic ammonia spikes, which will happen occasionally with new tanks. These spikes can also happen in older tanks, especially if the filter is thoroughly cleaned out, which will destroy the bacterial colony and cause the cycle to stop temporarily. Signs of ammonia poisoning include gasping for breath and redness around the eyes and nostrils from chemical burns.
Keeping a test kit on hand makes it easy to see whether the nitrogen cycle is healthy and stable. A stable tank should always read 0 ppm ammonia and 0 ppm nitrite. Nitrate should read between 5-50 ppm. This indicates that ammonia is being metabolized into nitrite, and nitrite is being metabolized into nitrate. Nitrate can only be removed through water changes, so after the tank reaches 50 ppm, a water change should be done to reduce the nitrate content.
Maintaining a healthy nitrogen cycle involves doing periodic water changes to reduce nitrate, testing the water to make sure the parameters are good, and occasionally adding a dose of bacterial supplement to keep the bacterial colony well populated. Having a good substrate for bacteria, such as ceramic filter media, also makes it easier to maintain good water quality. Finally, a regular care routine will ensure that the tank stays stable. Filter media should be rinsed regularly, but never completely replaced at one time. Replacement should be done gradually to allow time for the bacteria to replenish itself.
Instead of using one type of substrate, layering a number of substrates helps keep the water quality optimal. Ceramic substrate can help facilitate bacterial colonization, while filter floss can catch both fine and large debris. A layer of a chemical substrate such as carbon or zeolite can be added occasionally to treat temporary ammonia spikes or to remove medication from the water after treating a sick turtle. Having multiple substrates on hand is a good idea for these reasons, and will make it easier to maintain a healthy tank.
Maintaining water quality through the nitrogen cycle is extremely important, but turtle owners can use a number of additives to help stabilize water parameters. Not every product will be used on a regular basis, but a good deal of them are appropriate to add to the regular maintenance routine, and some of them are helpful to have on-hand in case of an emergency. Bacterial supplements are extremely important and should be added any time a large water change is performed, filter maintenance is done or a new turtle is introduced to the tank. This helps ensure that the nitrogen cycle is always taking care of toxic ammonia, which can kill turtles if it is not maintained. A stable yellow belly turtle tank should have no trouble with the nitrogen cycle or ammonia spikes, and dosing bacterial supplements periodically helps ensure that tanks remain stable.