How to Make Tap Water Safe for Fish Without Conditioner

Tap water is more than just H2O. It often contains chlorine, chloramines, and various metals that can be harmful to fish. While conditioners are a quick fix, they’re not the only solution. You can prepare tap water for your aquarium naturally, and make it safe for fish without using conditioner.

Test the Tap Water

However, before you start treating your tap water using the steps explained below, it’s important to know what’s in it. You can pick up a water testing kit from your local pet store or order one online. Brands like API and Tetra offer reliable kits that measure everything from pH to the presence of chlorine and heavy metals.

Testing your tap water gives you a snapshot of its chemistry. This includes pH levels, hardness, and the presence of chlorine, chloramines, and heavy metals. This information informs how you treat your water, ensuring you’re addressing the specific needs of your aquarium.

How to Make Tap Water Safe for Fish Without Conditioner

1. Use a Water Pitcher

Kitchen water pitchers such as Brita or ZeroWater use activated carbon filters or ion exchange resins to remove chlorine, chloramines, and heavy metals from tap water, making it safe for fish.

Using a kitchen pitcher to make tap water safe for your aquarium is a straightforward process. Simply fill it with tap water and let the filtration process work its magic. Depending on the pitcher and filter you choose, it may take a few minutes to a few hours for the water to be fully filtered.

For chloramine removal, consider the ZeroWater 10 Cup Pitcher. It uses a five-stage filtration system that includes ion exchange resins, and it’s certified by NSF for both chlorine and chloramine reduction.

2. Letting the Tap Water Sit

One of the simplest ways to make tap water safe for fish without using conditioner is to let it sit for 24-48 hours before adding it to your tank. This allows the chlorine to dissipate naturally through evaporation. Chlorine levels in tap water can drop by up to 80% after 24 hours of sitting. And if you’re really patient, leaving the water for 48 hours can reduce chlorine levels by a whopping 90%.

However, this method doesn’t remove chloramines or heavy metals, so it’s not a complete solution.

• Place a small fan near the water surface to enhance evaporation. The increased air flow significantly speeds up the process.
• To speed up the process and increase efficiency, use an air pump and an air stone. The increased surface agitation accelerates chlorine evaporation and oxygenates the water, making it more fish-friendly.
• Test the water after 24 hours to ensure that all chlorine has been removed.

3. Boiling the Water

Boiling your tap water is an effective way to remove chlorine, chloramines, and heavy metals. Bring the water to a rolling boil for 10-15 minutes, then let it cool to room temperature before adding it to your tank. This method is foolproof, but it can be time-consuming and energy-intensive.

4. The Vitamin C Trick

You might be surprised to learn that good old vitamin C can also help remove chlorine from tap water. Vitamin C neutralizes chlorine and chloramine without harming your fish or beneficial bacteria in the aquarium.

Adding just 10 milligrams of vitamin C per liter of water can effectively remove up to 99% of chlorine.

To use this method, simply crush up a few vitamin C tablets (make sure they’re pure ascorbic acid, not the coated kind) and dissolve them in your tap water. Let the mixture sit for a few hours, and voilà – chlorine-free water for your fish!

Pro Tip: Don’t overdo it with the vitamin C, as too much can lower the pH of your water. Stick to the recommended dosage, and always test your water parameters before adding it to your aquarium.

5. Using Campden Tablets

If you’re a homebrewer or have access to homebrewing supplies, you might have a secret weapon in your arsenal: Campden tablets. These little tablets are typically used to remove chlorine from brewing water, but they can also work wonders for your aquarium. One Campden tablet can effectively remove chlorine from up to 20 gallons of water.

Pro Tip: Campden tablets can also help remove other harmful compounds like chloramines, making them an excellent all-around solution for water treatment.

6. Expose the Tap Water to Sunlight

For those dealing with chloramine, sunlight can be your ally. UV rays from the sun can break down chloramine into chlorine and ammonia, which can then evaporate or be removed through aeration and biological filtration. Here’s how to harness the power of sunlight:

• Expose water to direct sunlight. Fill a transparent container with tap water and place it in a sunny spot.
• Wait it out. This process can take several days, so it’s not the quickest solution but effective for those who plan ahead.

7. The Botanical Approach

Nature has provided us with some amazing water-purifying plants, and you can harness their power in your own home. Introducing the humble pothos (Epipremnum aureum) or peace lily (Spathiphyllum)!

These common houseplants have been shown to effectively remove chlorine and other contaminants from water. Simply place a few cuttings or the entire plant (roots and all) into a container of tap water and let it work its magic for 24-48 hours.

• Tip: Rotate your plant cuttings every few weeks to keep them fresh and effective.

Tap Water is Not Safe for Fish

A study by the “Environmental Science & Technology” journal found that UV exposure could significantly reduce chloramine levels in water over time. Remember, this method requires patience and might not be suitable for emergency water changes.

Domestic tap water is a processed product intended for consumption by humans. Its composition depends partly on the original source and partly on the treatments given to it by the water companies and certainly won’t be suitable for fish in its raw state.

Heavily populated cities are often connected to more than one supply. When demand increases, water companies may supplement local supplies with water from another area. This water may be of different chemical composition to the regular supply and the hardness and pH may vary. It is, therefore, necessary to check it with a suitable test kit periodically or enquire with your local water authority about its composition.

Fish possess a slimy protective coating to protect themselves against harmful bacteria and other pathogenic organisms. This coating however, does not protect the fish from the various chemical treatments that some water companies use to ensure that domestic tap water is safe for human consumption.

Exposure to raw tap water will result in most fish reacting by spreading their fins and breathing rapidly and in some cases, may induce a fatal shock. Some hardy fish can tolerate raw tap water but they are certainly destined for a shorter life span than those kept in the prepared water.

Tap water is usually treated to become slightly alkaline (pH 7.5 to 8.0) to reduce corrosion of main pipes. This is suitable for most fish but plants in particular fair better as the pH drops below 7.0. Total hardness varies depending on the collection area.

Water collected from areas where rocks contain limestone is generally hard and by contrast, water collected from areas that are high in organic material is often soft. See The Water Cycle for more details.

Tap water is also treated with chlorine to kill microorganisms. Chlorine is a disinfectant which disappears if left to stand or is aerated for 24 hours. It can also be removed by a commercial product such as Tetra Aqua Safe. These products generally contain sodium thiosulphate but many also have added protective colloids to reduce the stress on the fish caused by raw tap water.

Chlorine reacts with any ammonia in the water to form chloramines. More water companies are now using chloramine as a disinfectant because they take a longer time to disperse than chlorine alone but this unsuitable for the fish keeper.

Again commercial products are available to remove chloramines or they can be dispersed by aerating for up to 5 days or by using carbon filtration.

There is some good news however. Water companies are beginning a trend towards treating with ozone and chlorine dioxide which reduce the formation of the compounds that are undesirable to fish keepers.

Domestic water supplies may also contain other fish irritants such as a quantity of copper. While copper is often use as treatment for disease organisms such as Oodinium sp. fish become distressed by a copper level as low as 0.5 mg/l (0.5 ppm).

Copper may build up in water which has been standing in copper pipes or hot water cisterns, particularly in soft water areas.

As a precaution, I recommend running some waste before using tap water for your aquarium and I advise against using any hot tap water as it may have been held in a hot water cistern (usually made of copper) for some time.

Additionally, hot water cisterns collect a lot of debris particularly carbonates which are undesirable to soft water fish.

There are many commercial products that are available to prepare tap water so that it is safe for the aquarium. It is advisable though, to inquire with your water company to ensure that your chosen water preparation treatment will remove the necessary chemicals as not every treatment removes every contaminant.