Pet Turtle : Water Purification

This is of utmost criticality. Turtles spend most of their lives in water. In their natural habitats the water gets replaced all the time, but this is not so in the captive habitats. Imagine their plight - swimming, eating, drinking and defecating in the same water!

Turtles generate a large amount of waste - this is because they are messy eaters and also excrete copiously. Turtle excreta comprises both visible solid (and semi-solid) and invisible liquid components. If the tank is not properly maintained (filtered & cleaned) this can cause the water to get filthy, increase ammonia levels and spawn rapid organic growth in the water. The end result - a turtle in dirty water, disease and death!

Water cleanliness can be primarily maintained through two means - regular withdrawal of tank water and replacement with clean water, and a good filtration system.

Water-Changing
The best way to keep the tank water clean is to change it everyday. But that can be quite a tedious and time-consuming activity. Therefore, a most people adopt a partial water-changing schedule along with a filtration system.

The water that you put in the turtle tank doesn't need any special treatment, as long as it is fit for consumption by human beings. Tap water is fine, but its better if you can use water filtered through an AquaGuard or similar device (considering the poor municipal water quality in a lot of Indian cities). If you are not filtering the water, we recommend standing the water overnight in a bucket to remove the chlorine. Chlorine removal tablets that are easily available can also be added, but these increase the water alkalinity and if possible should be avoided.

Some water-changing schedules we suggest (you can follow anyone based on your convenience). These are merely suggestive you can alter the water-changing schedule based on your tank requirements.
OPTION 1: Change 20% of the water every 2 days, replace full tank every 10-12 days
OPTION 2: Change 50% of the water every 5 days, replace full tank every 12-14 days
OPTION 3: Change 50% of the water every 7 days, replace full tank every 17-19 days

(Option 1 is recommended for small tanks, Option 2 is the most convenient for medium to large tanks, Option 3 should be followed only if you have invested in a high quality external filter!)

We recommend cleaning and disinfecting the tank, every time the full tank water is replaced or atleast once every 45 days. For more information on cleaning, click here. You can also add 1 level teaspoon of common salt for every 4-5 liters of water. This prevents the growth of 'bad' bacteria and prevents shell and skin diseases.

Some solutions that help disinfect/keep the water clean are readily available at most pet stores. These can be added as required.

Filtration System
This is the heart of your tank, so choose well and don't penny-pinch as this could have serious repercussions later on. The filtration required in a turtle tank is twice that of similar size fish tanks.

There are three types of filters generally available - Underground, Submersible and External. Most Indian pet stores don't stock the 'external' pumps as they are quite expensive compared to the other two. (At times being 5-10 times more expensive!) This is because most good quality pumps are imported into India.

Underground pumps are a strict "No-No" for turtle tanks, as they require a fine layer of gravel to work effectively, as it is advisable not to use that in a turtle tank. Most international literature recommends external pumps, and we don't doubt the superior filtration power they have, but feel that a cheaper and equally effective alternative could be 1 or 2 high capacity submersible pumps.

When deciding on the pump capacity, consider the amount of water (in liters) your tank contains. Compare that with the flow rate of the pump, which is usually mentioned as X lit/hr. These are ratings obtained under 'ideal' conditions, decrease by 75% to obtain the effective flow rate.

The pump you choose should be able to completely recycle the water in your tank in 1hr, with the 'effective' flow rate.

e.g.
Your tank capacity is 200 liters.
The pump you see mentions a flow rate of 400-lit/hr. The effective flow rate is therefore 100-lit/hr. i.e.; this pump can recycle 100 liters of water per hour.
So to completely recycle the water in your tank in 1 hr - you need 2 of these pumps or a single pump with a mentioned capacity of 800-lit/hr.

You need to keep you filter running on for atleast 10-14 hour daily. If possible you can time it to run for 2 hrs at a stretch, then stop for 2 hrs�and so on. You should always have the filter running after mealtime.

Filter Cleaning
All filters need to be cleaned regularly. The bigger the filter, the less often you will have to clean it, so if you can afford it, go for a bigger filter. Most submersible filters use foam as the filtering medium. We recommend you clean the foam every week, by rinsing it thoroughly under a strong jet of cool clean water. It is also advisable to rinse the filter components/casing.
Filter foam should not be subjected to strong detergents, or other cleaning ingredients, as it tends to absorb these. It could release these chemicals into the tank water later, polluting it.

Monitoring Water Quality
The water-changing schedules and filtration capacity selection process are suggestive - every tank has its unique water purification requirement that is dependent on a multitude of factors. Eventually (through experience) you will be able to observe the color and smell of water to diagnose when it requires changing. A strong stench or change in watercolor - requires immediate water replacement and a full tank cleaning.

While you spend a few months with your habitat observing water quality and climbing up that experience curve, we recommend you monitor water quality using a simple water-testing kit (for pH level). These are easily obtainable from your local pet store. Use it every 4 days for the first month, changing the water or modifying the filtration equipment to get the desired pH.

A pH level of 7 is neutral, anything more is alkaline and less is acidic. In a turtle tank the desirable pH level is between 5.5 to 7 (i.e., slightly acidic).

Fishes are natural monitors of water quality. And while a fish enthusiast might scrounge at the thought of fishes being used as testers - one cant escape the fact that their increased sensitivity to deterioration in water quality can provide 'visible' early warnings. So you may keep a few fish, and observe their fins, eyes and gills carefully for any changes. (But please don't get too attached to them, as they CAN end up as your turtles' snacks!)

For more on keeping fishes in turtle habitats, click here.