Can Goldfish Live in Tap Water?

Most goldfish keepers know that their aquatic pet needs fresh, clean water to survive. They, however, are divided on whether tap water is good for goldfish. In fact, goldfish are extremely hardy, which has led some people to believe they can live perfectly well in tap water. But is that true? Can goldfish live in tap water?

Untreated tap water contains chemicals that could be harmful to your goldfish.  Ideally, you should avoid adding water directly from the tap. In fact, some harmful additives and toxic substances in tap water can pose a grave risk to the survival of your aquatic pet. However, it is perfectly fine to use properly treated tap water.

If you are planning to keep goldfish in your aquarium for the first time, you may have some questions about their ideal living conditions, water environment, and whether tap water suits them. This article aims to answer all your questions.

Can keeping your goldfish in tap water kill them?

Typically, tap water contains chlorine and chloramines. In fact, these are added to kill the bacteria in the supply water. Unfortunately, these are toxic enough to kill your goldfish as well. Chlorine not only causes surface burns, but absorbs into the fish’s bloodstream and can even kill them. While the amount of chlorine in tap water varies across regions, even low concentrations can damage their respiratory organ called gill. Chloramine, on the other hand, consists of high amounts of ammonia, a substance that can quickly poison the fish.

Do other chemicals like nitrates in tap water affect goldfish?

Chloramines aren’t the only kind of danger you should be wary of. In fact, tap water in some areas could also contain nitrate, a bi-product of ammonia. Even fish waste contains nitrates. So, it is important to keep nitrate levels of the aquarium water in check. Otherwise, it can cause nitrate poisoning. In fact, high levels of nitrate can even kill your goldfish. Likewise, high levels of phosphate and iron may give rise to algae growth, which is again detrimental to fish health.

Is tap water harmful to the ‘good’ bacteria in your goldfish tank?

Not all bacteria are bad or harmful for goldfish. In fact, some ‘good’ bacteria help break down ammonia in goldfish’s waste to nitrites and nitrates. However, chemicals in tap water can kill all the bacteria, including the ‘good’ ones. As a result, ammonia can build up in the tank and cause serious harm to your goldfish.

How to treat tap water for chlorine?

There are many ways to remove chlorine from tap water. For instance, you can add Sodium thiosulfate to the water. It is easily available at pet stores. Usually, only a drop or two would be enough to neutralize chlorine in a gallon of tap water.

You can also use another technique called de-gassing. So, all you need is to leave the water in a tank or bucket with an air stone or filter. Within 48 hours, the chlorine will escape to the atmosphere on its own. However, this method is not very effective in removing chloramines in the water.

What are some signs that poor tap water quality is affecting my goldfish?

If you notice your goldfish are swimming in an erratic manner or staying close to the surface, this could be a sign that poor water quality is affecting their health. In fact, poor tap water quality can cause chlorine poisoning in the water. Typically, chlorine poisoning causes red patches over their body.

Ideally, you should use a dissolved oxygen meter (DO meter) to regularly check the dissolved oxygen level of your tank water. For high dissolved oxygen levels, however, consider reducing the temperature of the water.

What are some ways to test tap water?

Once you know that the tank’s water is not fit for your goldfish, testing can help pinpoint what it is that needs treating. Are high ammonia levels to blame? Or is the water too alkaline? Or, maybe your de-chlorinator is not effective enough.

You can conduct certain water tests at home, using test kits. For instance, if you suspect high ammonia levels, use an ammonia kit to perform an ammonia test. You’ll also find pH, nitrite, and nitrate water test kits at local pet stores.

How to make tap water safe for goldfish

You must treat your tap water before using it for your goldfish tank. Thereafter, you should conduct timely partial water changes in order to keep nitrates and algae growth in check. In fact, regular water replacement helps remove any harmful substances, toxic gases and heavy metals from the tank water. In addition, it helps to increase the amount of oxygen in the water. So, the general rule is you should replace one-fifth of the water in your goldfish tank with fresh water on a weekly basis. Ideally, you should use a siphon for the job. Here are a few other ways to keep the toxic substances in control.

Treat tank water with a water conditioner

Typically, you should treat your tap water with a water conditioner before adding it to the aquarium. However, you can also add a few drops of water conditioner directly to the tank water. In addition, consider adding tonic salts to the water, especially when your goldfish is sick. In fact, even a little amount of salt in the water can improve their gill function and heal injuries.

Introduce live plants

Goldfish often forage around in the aquarium for live plants. More importantly, live plants help neutralize the nitrates tap water and make the tank environment safe for your fish.

Can I use corals or marine rocks in my goldfish aquarium?

Corals and rocks can cause chemical changes in the water. For instance, shells or rocks can add calcium to the water. In addition, they can alter the pH level of the water. So, it is not recommended to use corals, rocks or shells in your goldfish tank.

What pH level is ideal for goldfish?

Usually, goldfish do not adapt very well to sudden pH changes. In general, the pH level of water helps determine how acidic the water is. Since goldfish are freshwater fish, they are comfortable with a water pH level of 6 to 7. If your goldfish is suffering from a lack of appetite or seems to be agitated, it is time to conduct a pH test. So, if the pH level is low, consider adding buffering products to the water. On the other hand, add RO-purified water when you need to lower the pH level.  

Is boiled water safe for goldfish?

Typically, boiled water is considered safe for drinking. Hence, many people assume that boiled tap water is safe for goldfish too. However, boiling does not help remove chloramines in the water. So, adding an effective de-chlorinator is essential to get rid of the chloramines from tank water.

Can bottled water be used for a goldfish tank?

While you can use bottled water, you should make sure that the water is not demineralized, distilled, ionized or flavored. In fact, you should use natural spring water bottled at the source. Even RO-filtered water is not fit for goldfish tanks as it doesn’t contain the essential minerals for your goldfish.

To what extent are heavy metals in tap water harmful for my goldfish?

You might aerate the tank water to remove its chlorine, but another problem persists. Usually, tap water contains heavy metals like cadmium, copper, lead and zinc, thanks to industrial mining. Unlike chemical compounds that may break down eventually, these contaminants are rather hard to remove from water bodies. They can affect the nervous system and respiration of your fish. However, heavy metals aren’t always bad for the health of your goldfish. In fact, goldfish need some amount of heavy metals. However, high amounts of heavy metals could be detrimental to their health. One solution to this problem could be using water filtered through reverse osmosis.

What kinds of filtration are available to treat tap water for my goldfish tank?

After you’re done removing chlorine from the tap water, you should conduct a few different types of filtration to make the water safe for your goldfish.

Carbon filtration

This process filters out the metal contaminants in water. Typically, you need to use activated carbon filters to carry out this type of filtration. Also, these filters help remove dirt, oil and other debris in tap water. 

Deionization and reverse osmosis

Reverse osmosis removes the impurities of the water. On the other hand, deionization helps get rid of the charged particles in tap water. 

While filtration is necessary to keep the water clean, excessive filtration can leave your tank water short of the necessary salts and minerals. So, it is necessary to replace your tank water at regular intervals.