Frog in Water

A Complete Guide on Safe Water For Amphibians

Finding the best water for your amphibian can be a daunting task. With pH levels, minerals, and water hardness, it’s easy to feel uncertain whether or not you’re providing your pet amphibian with water it can live in. That’s what this guide is for. With a little knowledge about water and, of course, amphibians, you’ll be an expert in no-time.

It all boils down to a few factors. The first being toxins; things like chlorine, ammonia, and excessive heavy metals are harmful to amphibians. The pH levels (the measure of alkalinity and acidity) should be neutral. Finally, determine the best water hardness for the species you’re keeping and ensure the water is not void of naturally-occurring minerals.

But don’t let the previous paragraph oversimplify this topic. It’s important to understand how these different elements affect amphibians what you can do to provide the best water conditions.

Why Amphibians Need Clean Water

Before we uncover the optimum water quality for amphibians, we need to understand why it’s important in the first place. To answer this question, we need to take a closer look at amphibians.

This guide is mainly geared towards frogs and toads but it applies to most amphibians as well. Having said that, I understand not all amphibians are the same and optimal water conditions may vary depending on the species you’re caring for but this guide covers most amphibians, not just frogs!

Most amphibians not only breathe through lungs but they breathe through their skin as well. Amphibians have a thin, membranous skin containing a complex network of blood vessels where respiratory gases are diffused. To put it simply, they absorb oxygen in the water that comes in contact with their skin. As you might have guessed already, toxins in the water are absorbed too.

Things like chlorine, pesticides, heavy metals, and chloramine are detrimental to amphibians. Because of this, it’s important to provide them with clean, toxin-free water. Tap-water, depending on where you live, might contain chloramine and other chemicals. We will take a look at the common sources of water in the section below and determine which is best and how to condition water to make it suitable for amphibians.

The Qualities of Good Water for Amphibians

Now that we know why clean, toxin-free water is important, let’s take a look at what qualities in water are optimal for amphibians. Aside from removing harmful toxins, the pH levels and water hardness, or minerals, are the main contributing factors.

pH Levels

pH stands for “Potential of Hydrogen” and refers to the measure of alkalinity and acidity of water. These levels are measured on a scale of 1 – 14. Lower numbers mean the water is high in acidity while higher numbers mean the water is more alkaline or “basic”. Water with a pH of 7 is considered neutral, which is the preferred and recommended level for most amphibians.

This can fluctuate within 1 point up or down and, for the most part, will prove habitable for your pets. Some species prefer a pH around 6.5  but the general consensus amongst experienced keepers is this; A neutral pH level (between 6.5 – 7.5) is optimal for most amphibians.

The pH Scale

Adding a very small amount of baking soda will raise the water’s pH levels, making it more alkaline. Also, be aware that baking soda is high in sodium (salts) so, as you’re adjusting and testing the water’s pH levels, do so with small amounts of baking soda.

One teaspoon of baking soda in 10 gallons of water is a good starting point. Mix in the baking soda and allow some time before checking the water’s new pH levels. Do this process in a separate container, away from your amphibian. Once you have the desired pH, do a partial water change in your amphibian’s tank and recheck the levels. Amphibians do not like sudden, drastic changes in water so it’s important to do partial water changes rather than changing all of it at once.

Water Hardness

You’ve probably heard people mention “hard water” or “soft water” before. When someone refers to hard or soft water, they’re talking about the overall mineral content. The mineral most associated with hard water is calcium. Soft water has fewer minerals while hard water has more and its measured in degrees of hardness or “dGH”.

Very little research is available on the effects of water hardness on amphibians. A study conducted by M.T. Horne and W. A. Dunson in 1995 shed some light on the effects of pH, naturally-occurring metals, and water hardness for wood frogs and Jefferson salamander larvae. The objective: test the effects of those water conditions over a period of 7 days and 28 days. Hard water increased the wood frog’s survivability while soft water had a negative effect.

While these findings suggest hard water is better, that’s not exactly the case. This study was conducted with the reproduction of larval amphibians in mind. It also doesn’t specifically target water hardness. pH and naturally-occurring metals were variables as well. Regardless, water with no minerals has a negative effect on amphibians and it’s not something they naturally live in.

Perhaps the best method to determine the preferred water hardness of your amphibian is to find water-hardness maps. Research the species you’re keeping to find their native location and learn what types of water they live in. Is it soft water or water high in minerals?

Water Hardness in US


If you’re unable to find sufficient data for your amphibian, I suggest using slight water hardness between 2 – 3.5 grains per gallon. Amphibians tend to do well in soft water or “slightly hard water” around 2 dGH. The best method for testing water hardness is to get a digital water quality meter. They are cheap and, more the most part, accurate.

Do not to use water softeners that replace calcium and magnesium with sodium chloride! Hard water minerals, in small amounts, are good for amphibians and so are salts! But replacing calcium and magnesium with salt (sodium chloride) can lead to a dehydrated amphibian!

Common Water Sources

At this point, we know why toxin-free water is important and we have an understanding of optimal pH levels, salts and minerals, and water hardness. Now let’s look at different sources of water and determine whether or not they are suitable for amphibians.

No matter which source you get water from, it’s a good idea to test the water before placing your amphibian into it. This can be accomplished by using an aquarium water test kit. It’s an inexpensive way to test the water and ensure your pets are in a safe environment.

API is a trusted brand and their freshwater master test kit tests for ammonia, nitrates, and nitrites as well as measures the water’s pH levels. If, however, you need to test the water for a different chemical like ammonia, you will need to find a different test kit.

Tap Water

Whether or not your tap water is safe for amphibians largely depends on where in the world you live. Many cities monitor their water quality regularly but it’s important to remember that this water is intended for human usage. Chemicals like fluoride and chloramine are used to purify water and, in small doses, are considered safe for human consumption but they can be deadly for amphibians.

I suggest calling your city to find out everything that goes into their water supply. If no chemicals are added, you’re probably good to go. One chemical to watch out for is chloramine. Unlike chlorine, which dissipates over a short period of time, chloramine remains in the water for long periods of time.

Since chloramine is a combination of chlorine and ammonia, you have a few options in removing it from your tap-water. Amphibian-safe water conditioners claim to remove chloramine while boiling water for 20 minutes is said to remove it as well.

If your water just has chlorine in it, you don’t need a water conditioner at all. All you need to do is let the water sit out for 24 hours and the chlorine will evaporate.

Well Water

There is not a cut-and-dry answer for this one since the quality of well-water, much like tap water, depends on the area you live in. The only sure-fire way is to test your well-water and adjust the pH and water hardness as needed.

Distilled Water

Distilled water is essentially 100% water with zero impurities and no minerals. Having pure water is great in some cases but amphibians need water with trace minerals and a neutral pH level. Because of this, I do not recommend distilled water unless you reconstitute the water with minerals.

You can use calcium chloride and magnesium sulfate, as well as other commercial products, to add minerals back into the distilled water. This will increase the water hardness and in most cases, it will affect the pH levels too. As always, be sure and test the water before introducing your amphibian to it. Some people have even resorted to making their own mixture of minerals but because I have not tested these ‘recipes’ I will not suggest them here.

Bottled Water

Using bottled water is, for the most part, safe for amphibians. Toxins are removed through a series of filtration systems like “activated carbon filters” and “anion exchange water softening treatment”. Reverse osmosis is even listed as one of the methods used by many of the top name-brand companies. Once it’s cleaned, minerals like calcium and magnesium are added back into the water. These companies even claim their water is neutral in pH or slightly alkaline.

That all sounds great but, unfortunately, companies stretch the truth and flat-out lie in some cases. During my research on bottled water, I came across an interesting video which tests the pH levels of a handful of different bottled waters. The results aren’t terrible but they’re far from perfect. The video, while not pertaining to amphibians, is closely related and definitely worth watching.

The takeaway is this: bottled water is one of the best sources of water for amphibians. I do suggest, however, that you test the pH levels and adjust accordingly. This should go without saying but depending on how much water you need, this can get expensive. Aquatic frogs like the African clawed frog require a lot of water while other species only need a large bowl of water or partial water bottom.

Reverse Osmosis

I won’t pretend to know everything about reverse osmosis and how it works but the basics are this: Pressure is used to force water through a semi-permeable membrane (a barrier), leaving behind the contaminants. It’s not 100% successful at removing bacteria’s but it’s a better option than the activated carbon filters used in most household water filters (like brita, PUR, etc).

The water that comes out is very clean. Unfortunately, it’s too clean for amphibians because most of the minerals have been removed. Reverse Osmosis is a great option but you’re required to reconstitute the water by adding minerals back into it.

Like the activated carbon filters, reverse osmosis is a barrier filtration system. In fact, there are several filters in a reverse osmosis system. So, eventually, the quality of clean water decreases. Because of this, distilled water is regarded as a superior product.

Boiling Water

Boiling water is an age-old method used to purify water. When done properly, boiling water kills most pathogens and bacteria. It does not remove heavy metals like lead, fluoride, and arsenic. For this, you’ll need a barrier based filtration system like activated carbon or reverse osmosis.

In the last paragraph, I said “boiling water kills most pathogens and bacteria”, but, contrary to popular belief, water doesn’t need to be boiled to remove disease-causing organisms. Pasteurization kills most water-borne pathogens and only requires raising the water temperature to 160 degrees Fahrenheit. Maintaining this temperature for 30 minutes is a common method.

Unfortunately, as I mentioned earlier, pathogens aren’t the only thing amphibians need to worry about. Chemicals like chlorine and chloramine won’t disappear during the pasteurization process. Boiling water for a full 20 minutes is the most commonly suggested method for removing chlorine and chloramine and even that has mixed reviews.

Chloramines are derivates of ammonia and chlorine and they’re a bit more difficult to remove. I recommend buying an ammonia test kit if you’re considering boiling water tap-water containing chloramine. On a good note, boiling water does not remove minerals! And this should go without saying but give the water plenty of time to cool before using it!

Rain Water

Aside from the process of getting and storing rainwater, it’s usually a good source of water for amphibians. It all depends on how you obtain the rainwater. Try to avoid collecting rainwater runoff from sources treated with chemicals. Nowadays, farmers spray their crops with pesticides and other chemicals, so using a bucket to scoop rainwater from a puddle near farmland is a bad idea.

My suggestion is to construct a tarp or similar structure and use it to funnel rainwater in a bucket. You should also know that air pollution effects rainwater and because it’s a soft water, I suggest checking the pH before using it.

Pond, River & Lake Water

While there are likely thousands of amphibians living in ponds, rivers, lakes and other bodies of water in your local area, most keepers, including me, discourage using these sources for your captive amphibians. Mostly due to waterborne pathogens, parasites, and bacteria.

The native species may not be affected by parasites in this water but it might harm or kill your captive amphibian.

Water Conditioners for Amphibians

At this point, we’ve covered the most common sources of water and looked at a few methods for adjusting pH levels and minerals to the optimal levels for amphibians. Now let’s look at another great option for treating water.

A number of companies have developed amphibian-safe water conditions which remove chloramines, nitrites, chlorine, and ammonia. They also add electrolytes and helpful ions to hydrate your pets. These products are considered a “must-have” item for everyone keeping reptiles and amphibians.

Leading the way are ReptiSafe and AquaSafe. Both companies have stellar products and I cannot recommend one over the other, as they’re both incredible products. Pick one up online or at your local pet store and squirt some into your tap-water to instantly remove chloramines, chlorine and other harmful toxins. Don’t squeeze half the bottle into your water all willy-nilly; read the directions first and be precise when measuring the correct portions.


For captive amphibians, quality water is just as important as a proper diet, humidity, temperature and cage size. But don’t let water-quality stop you from buying your first frog, salamander or another amphibian you want. With a few cheap tools and the knowledge you’ve learned here, you’ll be providing your amphibians with water they can thrive in.

Remember, use toxin-free water, test the pH levels and adjust accordingly, and use water with natural minerals and your amphibian will do just fine!

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