To begin, cycling refers to the process that establishes a biological system in your aquarium that will ultimately allow the aquatic animals to survive in the very water they pollute with their own waste products.  This is accomplished by a series of beneficial bacteria what work in different stages to break down this biological waste into several products that are less toxic, and ultimately manageable.

Once the turtles are introduced into their new environment they begin to deposit their waste products into the surrounding water. These waste products are the initial food source for the bacteria that will eventually become your biological filter.

As this food source becomes available, the various forms of bacteria begin to process these waste products, and through their establishment, form the biological filter system that will help your aquarium to remain clear and clean. During the initial cycling period it is common for the aquarium to show a whitish clouding due to the progression of these bacteria. This shows that the cycling process has begun, once the cycling is completed, the water will begin to clear.

These beneficial bacteria have certain requirements to establish themselves in your aquarium; oxygen, a physical surface for them to “colonize”, and of course, a consistent food source (which will be the turtles waste, uneaten food particles, and any dead materials within the water). It is important to make sure the bacteria have everything they need to help them through the cycling process. Since the food source is a given, let’s look at the other two requirements:

First, the bacteria need good oxygen levels in the aquarium water, this is provided primarily by water movement and water turbulation. Having your filter “spray” the filtered water back into the aquarium to agitate the water helps to increase the oxygen levels. A separate “bubbler” or airstone with a small aquarium air pump also works well.

Next are the actual surfaces where your bacteria will set up shop. These bacteria will colonize almost any surface within the aquarium that has adequate water movement and available oxygen. Many filtration units will have specifically designed areas within the filter designated for “bio-media” which is simply some material for the bacteria to grow on. To supplement the filter, a one inch layer of medium grade gravel throughout the aquarium bottom provides an excellent bed for bacterial conization and can complement the filters bio-media nicely. This gravel bed should only consist of a size gravel that will allow water to pass easily through it (1/4 inch pebble works nicely) providing water movement and oxygen to the bacteria. Fine sand is not suitable for this purpose and should be avoided. 

Now the bacteria have everything they need to begin their establishing of a working biological filter within your aquarium. Cycling time can vary for each setup, but generally you can count on 14-28 days before the water clarity begins to improve and the aquariums biological filter stabilizes. 

During this beginning start up time, it is best not to preform water changes, as adding new water will usually prolong the final stabilization. If you are interested in watching the process in a more in-depth way, you can purchase an aquarium test kit that will show you the individual cycling of the ammonia, nitrites, and nitrates, as the bacteria work their magic.

Once your aquarium fully cycles, there are normal maintenance procedures that you will perform to keep you biological filter healthy and working; vacuuming the gravel bed to remove any materials that may have settled there, and replacing 25% of the water should be performed monthly (along with your regular filter maintenance).

Just go ahead and think of your bacteria as part of your aquarium family, if you take good care of them, they’ll reward you with a clean, healthy aquarium environment for your turtles, and less work and stress for you.