How To Make Tap Water Safe For Fish Without Conditioner {Does Conditioner Kill Fish?}

One of the essential living parameters for fishes is the water condition of the tank. Do you want to know how to make tap water safe for fish without conditioner?

The water condition of an aquarium can go a long way in determining how healthy your fish will be and how well they will thrive.

In this article, we’ll ditch the conditioner and find better alternatives. Are you with me?

How To Make Tap Water Safe For Fish Without Conditioner

Several methods are used as an alternative for conditioners in treating the water used for aquariums. You can make tap water safe for fish without conditioners by making use of alternative means such as:

  • reverse osmosis system
  • electromagnetic water treatment
  • template-assisted crystallization
  • leave tap water to sit for about 26-28 hours before aerating it.

These alternative method of water treatment can prevent your fish from being exposed to harmful chemicals aside from making the water suitable for them.

Although some of these methods are quite technical, they are relatively safe. It might also be a little more expensive, but it’s worth it after all. Allow me to explain in detail below.

Make Tap Water Safe For Fish Without Conditioner

Can Fish Live Without Water Conditioner?

Yes. People often say conditioner is vital to make tap water safe for fish because it helps in treating the water.

It can also soften the water to keep it ideal for fish to thrive. However, there are much more to keeping a fish alive in the aquarium than just adding conditioner to tap water.

Although aquarium owners should not use tap water without any treatment, you can employ alternative means of water treatment. It would help if you also made the water germ-free to protect your fish.

Can Too Much Water Conditioner Kill Fish?

Yes. Some conditioners used to contain chemicals that are harmful to the survival of fish in the tank. To be precise, most chlorine-based disinfectants are detrimental to fish.

They are capable of damaging the gills and skin surface of the fish, which is as bad as the untreated tap water itself.

Exposure of fish to a high level of chlorine-based disinfectants and other harmful chemicals can let them show signs of:

  • irritation
  • erratic swimming
  • repeated attempts to jump out

However, the chemicals might not be so life-threatening at lower concentrations.

Is Conditioner Necessary If the Tap Water Is Filtered?

No. There would be no need to use a water conditioner if the water filter removed both:

  • chlorine
  • chloramines

However, if the filter is a RO filter, be aware that is must be mineralized. Pure RO water isn’t enough.  You can also let water sit and vigorously aerate it for 26-48 hours to drive off the chlorine gas.

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Reverse Osmosis for Aquariums

Reverse osmosis system is one of the most reliable non-chemical based methods of making tap water suitable for fish.

It can:

  • remove up to 99% of all dissolved solids in water
  • make water suitable for human consumption
  • remove impurities and other chemicals like fluoride and chlorine from water.

This ability to remove fluoride, chlorine and some other chemicals from water is why it is considered an excellent alternative for conditioners.

Is Reverse Osmosis Safe?

Yes. Aquariums may use reverse osmosis water without any problems. Aquariums can benefit from reverse osmosis water since it can help remove dangerous impurities from the water.

The pH level in your aquarium may also be stabilized with reverse osmosis water. Also, reverse osmosis does not require too much energy, so you don’t have to worry about power consumption.

Does RO Water Have Minerals?

No. There are very little minerals left in RO water that has been purified.  After the reverse osmosis process removes all minerals, you may want to increase the alkalinity of the water can with remineralizing cartridges.

Those who have aquariums that require more alkaline pH levels may find this to be the perfect option. Aquarists also love using deionization cartridges.

This is why RODI or RO/DI systems, which combine reverse osmosis with DI, are immensely popular options for aquarium owners.

Tips For Chemical-Free Tap Water

Here are some alternative techniques you may attempt if you don’t want to dechlorinate the water in your tank with chemicals.

1. Let it Rest

Letting your water rest is the simplest chemical-free method of dechlorinating it. But this procedure also takes the longest to complete.

It may take 1 to 5 days for the chlorine and chloramine to entirely disappear after letting the water settle.

However, in most situations, 26 hours is sufficient time to remove the water.

2. Heat the Water

Simply boiling the water in your tank will dechlorinate it quickly and effectively. When water is boiled, all of the chlorine and chloramine are released. One of the best ways to eliminate chloramine is to boil the water.

The procedure will nevertheless take some time. In actuality, 10 gallons of water would require an hour to boil in order to eliminate 1 mg/l of chloramine.

Does UV Light Remove Chlorine From Tap Water?

Yes. The chlorine and chloramine in a tank can also be eliminated using UV light. But you’ll need a UV sterilizer to achieve it.

However, it will still take around 24 hours if you decide to use a UV light to remove contaminants.Try this tip with some of the others mentioned in the article above such as boiling the water, letting it sit and RO filters.


The most important thing to consider in using tap water for fish is not if you should use a conditioner or not. It is more important to focus on the safety of the water for your fish.

The alternative water treatment methods to conditioner are generally safer because it is not chemical-based. Exposure of your fish to a high level of chemicals can yield detrimental effects like irritation of skin surface and gills.

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Hello, I'm Jason. I'm the guy behind I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.