Your turtle’s paludarium needs a strong external filter, ideally sized at double the tank’s water volume, left running day and night. This keeps the water pH-neutral, which your turtle needs, without constant water changes. Even with a powerful filter, change about a third of the water every month, since things like nitrates are never fully filtered out.

The water in which your turtle lives can become quite dirty. A paludarium can hold hundreds of litres of water and you don’t want to have to change this water too often. More importantly, a turtle needs pH-neutral water (pH 7) which is why a filter is an essential purchase for turtle owners.

Filters

It is vital that you provide your turtle’s enclosure with a strong external filter, possibly in addition to an internal filter. An external filter has multiple benefits:

• It generally has a larger capacity.
• It doesn’t take up any space in the paludarium.
• It needs to be cleaned much less often than an internal filter.
• It doesn’t create any sound within the paludarium, which helps your turtle(s) to relax.

By choosing a filter with a capacity which is double that of the volume of water used in the paludarium, you can be sure that the filter will do the job.

Leave the filter on day and night for optimal results – it will save you a lot of work and a lot of water.

However, if you prefer to use electrical appliances at night or if you find the filter to be noisy, buy a slightly larger and more powerful filter and leave it to work overnight with a timer.

We prefer JBL’s CristalProfi filter. It features a biodegrading mechanism, so it doesn’t need to be cleaned too often and can be used in paludariums which hold 200 to 700 litres of water.

The Sunsun Aquarium filter is a good alternative: it has a flow rate of 660 litres and also provides biological filtration.

Cleaning

The greater the filter’s capacity, the less often you will have to change the water. However, even with a large, strong filter, it’s best to change about a third of the water every month because some things are not filtered. Nitrates, for example, will always be in your water.

You can buy cleaning products like Exo Terra’s Turtle Clean to help to control odours and to break down any stubborn organic waste; this helps to improve filtration efficiency as well.

You should also clean your filter from time to time, given that it collects dirt, although the frequency and level of cleaning will depend on the type of filter you have. Biological filters like the aforementioned models will require much less cleaning, for example.