The use of Free Chlorine & Chloramines with Aquatic Turtles

For years there has been discussions regarding the use of chlorinated water in Aquatic Turtle aquariums. Some sides maintaining that the small amount of chlorine is absolutely safe for the turtles, while others claiming that chlorine is completely unsafe for any animal to be in contact with. There are even some reptile product manufacturers that market Chlorine/chloramine “conditioners” and suggest treating all incoming water. But is chlorine or its newer form chloramine, really that dangerous for Aquatic Turtles? Let’s take a look.

First of all, what exactly is the difference between chlorine or “free” chlorine and this newer transformation- chloramine sometimes referred to as “bound” chlorine? We could talk at length about chemical compositions and properties, probably even show some molecule diagrams reminiscent of our days in chemistry class, but in friendly turtle fashion here are the differences:

Chlorine, or free chlorine, has been the major disinfectant of choice for drinking water across most of the developed world since the 1930’s. In the United States 98% of all drinking water is now treated with some form of chlorine. Good reason for this too, as chlorine has been proven to be extremally efficient in knocking off harmful bacteria and assorted pathogens from drinking water. The World Health Organization credits chlorine with controlling infectious diseases worldwide, while in the U.S. chlorine is associated with virtually eliminating typhoid fever, dysentery, and cholera. The only drawback to free chlorine is its short life span, due to its relatively high rate of evaporation.

Chloramine, or bound chlorine, is the relatively new kid on the block, chemically speaking. Chloramines are formed when free chlorine becomes “bound” chemically with some form of ammonia. This happens in nature in limited situations, but chemical engineering has been successful at producing chloramine in much larger amounts. Chloramines are on the move now in many areas to replace free chlorine in the common use of water disinfecting. In 2002 it was reported that 20% of water companies in the U.S. had switched to the use of chloramine and into 2020 it is now recognized that almost 1 in 4 people receive water containing chloramines. Why? While chloramine is admittedly not as effective as free chlorine in killing bacteria, chloramine does have one big advantage over chlorine – it has a much longer life span before it breaks apart and dissipates. This giving it more contact time to work as a disinfectant in comparison with chlorine.

It appears clear that the use of chlorine in some form as a major purifier of drinking water is here to stay, so if you’re dealing with water provided by local State and City municipalities, you and your turtles are going to be dealing with some form of chlorine.

So, what effect do these chemicals have on our turtles?

First, let’s face it, we have no reservations heading to the kitchen faucet to fill up our dog or cat’s water bowl. Same with the hamster and rabbit bottles, and most all our outside pets drink water supplied by the garden hose. Of course, we drink tap water, our young children, and our elderly. Sometimes we take bottled water with us as we head out the door, but reports show that half the bottled water sold is treated with chlorine also. The World Health Organization maintains studies dating back to the early 1950’s, which show no substantial adverse effects with the use of chlorine and drinking water. There has been some talk of possibly harmful “biological byproducts” associated with chlorine, but nothing proven. It appears that for all practical purposes, consumption of standard drinking water disinfected with a chlorine form has proven safe, for humans and animals. So, we would think, for our turtles also.

So, if actual consumption of the treated water is of little concern, what about contact exposure? Our turtles certainly ingest their fair share of water, but they also are exposed to these water born chemicals as they swim. Just like a human swimmer in a swimming pool, our turtles are exposed to the effects of these chemical disinfectants on their eyes and outer nasal cavities. Could this be an issue?

Truth is it very well could be, but the fact is that free chlorine -in itself- does not irritate the eyes. The CDC reports that eye irritation from pool water is actually a reaction of the chlorine with water contaminants, including urine. But chlorine combining with urine (as a source of ammonia) can cause a natural formation of chloramine, which can very possibly irritate the turtle’s eyes and nasal cavities as it does to human swimmers. If you are already dealing with chloramines in your water to begin with, then the possibility of some amount of slight irritation could be a logical conclusion in regard to your turtles.

As we look at all the information available, we can draw a reasonably accurate conclusion that the consumption of chlorine treated water is unlikely to have any adverse effect on our Aquatic Turtles. However, in regard to irritation of eyes and outer nasal membranes through contact with chloramines, it would appear that some concern could be warranted. Going forward it will be interesting, as the changeover from free chlorine to the use of chloramines continues throughout the U.S. – to see if conditions arise that seriously affect our turtles. At this point, only time will tell.

Until the time comes when definitive answers are available, it is always a safe choice to use some form of untreated water for use in your turtle’s tank. Spring water, well water, collected rain runoff, or RO water can all be safe choices. If you are forced to use local tap water, contact your local provider and find out what form of chlorine is being used, then you can deal with the situation correctly.

For additional information on the Topic of Removing Chlorine and Chloramines from your turtle’s water, please see Turtle-Tech’s bog article

“How to Eliminate Chlorine & Chloramines with Aquatic Turtles”.