Some people have concerns with chlorine in tap water, but there have been no reported problems with crested geckos. Certain other reptiles may be more sensitive – and amphibians and fish are definitely sensitive to tap water. If your tap water is safe (you can check quality reports online for most municipal areas), then there’s no real problem with using plain old tap water. However, if you live in an area with contaminated tap or well water, or if you have a variety of animals like fish and amphibians to care for, you should learn about chlorinated water and how to deal with it.
How is Chlorinated Water Harmful?
For most animals, chlorinated water is not a concern. Humans may find the taste unpleasant, and the water can still contain sediments and dissolved solids that could cause other issues of water quality. Always use water sources approved for human use. For example some outdoor pipes, spigots and garden hoses are not labeled for drinking water. They can impart lead and other harmful elements to an otherwise safe water source!
One concern for reptile keepers with glass or clear plastic enclosures is that the minerals in tap water cause hard water deposits. This impairs viewing and can interfere with adhesion of arboreal geckos, like cresteds.
Chlorine and chloramine are chemicals used to treat tap water to make it safe for human consumption; it is assumed that it is therefor safe for other non-aquatic vertebrates. Animals that don’t live in water ingest water orally, and the chemicals are broken down while it works its way through the digestive system, before reaching the bloodstream. These chemicals are used because they kill microorganisms that can make you – and possibly your pets – sick.
Chlorine and chloramine, a combination of chlorine and ammonia, are highly toxic to fish because it causes gill necrosis. Chlorine and chloramine may do the same thing to lungs if they were constantly exposed the way fish gills are to water containing the treatment. However, it’s just the nature of the aquatic environment and the way gills work. Similarly, amphibians like frogs, toads and salamanders have semi-permeable skin that lets a variety of chemicals access the bloodstream directly. The only direct harm to reptiles would be if they routinely soak in water and take in the chemicals via the cloaca, which may then enter the bloodstream without being digested.
So if you have chlorinated water, and don’t want to use it – what can you do about it? You can dechlorinate your water or you can use a different source. To make water safe for fish or amphibians, you need to either remove the contaminants from tap water or use a different source of water.