Can Guppy Fish Survive in Tap Water?

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The guppy fish breed is a tropical fish that is widely distributed in almost every place on the globe for indoor aquariums. Many people know this fish as the rainbow fish, or the million fish. You can find it in pretty much every animal shop that sells fishes and aquariums with accessories.

Since you arrived on this article, it’s possible you want to buy a number of guppies for yourself, or you already own them. How does tap water come into the picture in the case of guppies?

Most people use tap water for their fishes, when they change the water inside the tank. While the water is being changed, they put the fish in simple tap water.

Maybe this is the reason why you searched for this subject as well. In this article I will tell you if tap water is good for guppies, and if that’s the case, what should you do to be sure they can survive it.

Tap Water for Guppies

The first question that needs to be answered, is if guppies can survive at all in tap water. The short answer is yes, but only in certain circumstances. How this is possible to achieve, will be covered a little later in this article.

But for now, it’s important to keep in mind that tap water is usually dangerous for guppies. For why this is the case, I will tell you right now.

In most cases, tap water contains quite a big amount of chlorine. This substance is deadly for any guppy. It will kill them pretty quickly or slowly depending on how much of it there is in the water.

Chlorine is used as a disinfectant in tap water. It kills all the bacteria that is harmful to be consumed by humans. Because of this, most fish breeds, so guppies as well, will be affected by even small amounts of this substance.

Since this is the case, you shouldn’t put you guppies in tap water, even for a short period of time. Let’s say you want to change the water inside the aquarium. For the time being, you put the fish in some tap water, so they won’t die.

Well, guess what! Putting them in tap water in this example, even for a short period can affect your guppies very badly. They could even die in such a short period of time. I don’t think you want that.

So, how can you make sure they survive tap water? Let’s see!

Dechlorinate Tap Water

As you can see from this subtitle, you can dechlorinate the water before you put your guppies in it. How is this achieved?

A popular method that many people utilize regularly, is to use a dechlorinator device. Yes, this is actually a real thing that anyone can use to clean the water from chlorine. The best place to find such a device is Amazon.

I would recommend the Seachem Prime dechlorinator. You can find this product easily on Amazon by doing a quick search.

This product is basically a substance that if used, will clean the water from all the chlorine in it. You can get it in multiple different sizes. For start, the 1L package is all you need.

It works with both fresh and marine water. So, guppies won’t be affected in any way by this substance. And there is one additional perk that comes with it.

The Seachem Prime will not only rid the water from chlorine, but also from ammonia and nitrates that your fish are leaving behind. This means that you can use the product as a biological filter media as well. After all, a bio-media will clean the water from ammonia and nitrates that could harm your fish.

It’s a pretty good deal, considering that you get a product that does multiple things all at once.

But what if you don’t want to spend your money on this product? Luckily, there’s another method that’s used to dechlorinate tap water. However, this is not as quick as using the conditioner from above.

Even so, it’s quite efficient and will do the job like you’d expect. What is this about?

Just leave the tap water outside in a container for at least 24 hours. After at least this much time has passed, most of the chlorine will be gone from the water. It’s that simple. But to be sure there isn’t any more chlorine in it, just make that time a little longer.

This is actually the simplest way to get rid of chlorine in tap water. If you plan to put guppies in such water, don’t forget to dechlorinate it first.

There is one last aspect you really have to keep in mind when you put guppies in standard tap water: the temperature.

Tap Water Temperature

Since guppies are a tropical fish breed, they need a somewhat warm water to thrive in it. Mostly, an aquarium with water that’s at least 70 degrees Fahrenheit warm, should do it. But if you want to make them feel totally comfortable, 78 degrees is even better. You don’t need to go higher than that.

The problem arises when you don’t keep the aquarium in a warm place. If that’s the case, you must use a water heater, to make sure your guppies don’t get sick and die slowly.

If temperature is so important in the aquarium, you can’t ignore it in the case of tap water either.

When you put your guppies in dechlorinated tap water, make sure it’s the same temperature as the aquarium water before it. One or two degrees won’t make much of a difference, but be careful about warming it up to the right temperature.

If you don’t do this, your guppies will get sick in the tap water, and putting them back inside the aquarium, won’t make much of a difference.

To make things easier, you could keep them in a warm place, after the water was heated, just until you change the aquarium water.


Let’s recap quickly what be discussed in today’s article:

First, I told you that guppies are a popular fish breed that you can find in pretty much any animal shop. Because of that, it’s quite likely that you also own some of these in your personal aquarium, or maybe you plan to buy some.

Either way, it’s good to know how it’s best to deal with guppies when you plan to put them in tap water. The point is, that guppies can’t survive in standard tap water, only if you dechlorinate it first. The chlorine could sicken and even kill your guppies pretty quickly.

The product that I mentioned above in the article is quite efficient at cleaning the water from chlorine, but you can also use the second method I described above.

And don’t forget to maintain the water temperature at the same level, like the one in the aquarium.

If you do everything as described above, your guppies should be totally fine in tap water, while you change the aquarium water for them. But it’s best to put them back as soon as you can. After all, keeping them out of their normal environment isn’t something that’s good to be prolonged.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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