Home Fish Facts Can I Use Bottled Water For My Fish Tank ? (Quick Read)

Can I Use Bottled Water For My Fish Tank ? (Quick Read)

by gvald

Using bottled mineral or spring water for your aquarium? What a strange idea, you may ask?


Well, it is quite common in aquarium keeping. We explain everything about it.


Can you put bottled water in your aquarium?

Although it is indeed possible to fill your aquarium with bottled water, you should not use just any water.


Above all, select :

  • Spring water with low “ion” content (calcium and magnesium);
  • Water with the lowest pH: the lower the pH, the less charged the water.


You can choose specific waters to cut your tap water to balance the contributions. Moreover, from an economic point of view, we advise you to couple bottled water with packaged tap water.


As the parameters of bottled water are stable and reliable, you don’t need any special equipment to check their acidity, hardness, etc.


Why use bottled water for your aquarium?

Tap water is nowhere near the same quality. Some people have soft water, others have very hard water (limescale), and still others have water that is very high in nitrates.


At the same time each aquarium, and especially each species of fish or shrimp, has specific needs. For example for fish like Tetra, Scalaria or Discus, they need soft water. On the other hand for fish like African Cichlids or Molly, hard water is recommended.


The main reason for using bottled water in aquaria is to have a softer aquarium water. You can use bottled water alone, or cut up tap water with it. Some people also use bottled water to have a lower nitrate content.


When should I use bottled water for my aquarium?

You will have to determine your needs to start. Test the GH (total hardness) of your water coming out of the tap, if it is too hard for the needs of your fish (or future fish) you can consider using bottled water.


I recommend the use of bottled water for aquariums up to 60 liters. For larger aquariums it may be better to use osmosed water. Rainwater is another solution if you have the possibility to collect it easily, with a water collector for example.


Which water to choose for your aquarium?

Water is the essential element in aquarium keeping, it is the living environment of the fish. Its choice is therefore of primary importance.


The first thing in aquarium keeping is to know the needs of water quality (GH, KH and Ph) of the chosen species of fish before anything else, which leads to say that the water must be as close as possible to the characteristics of the water in the natural environment, in order to maintain your fish in the best possible conditions.


Piped water (tap)

The simplest solution and often used for beginners in aquaristics. It is true that it is easier to choose fish adapted to tap water than to adapt the water to the chosen fish.

We would say that the tap water on the French territory in general is basic and rather hard.


It is in principle very often adapted to ovoviviparous and viviparous fishes, to the fishes of the lakes of Tanganyika and Malawi as well as certain species of Central America.

Some regions, such as Brittany, are lucky enough to have rather soft and acidic water at the tap, which allows many species, but this is not the case in all regions of France and elsewhere.


Tap water should always be prepared, either with a conditioner so that it can be changed directly or by letting it sit for one or two days to get rid of its chlorine.



Rainwater is pure, it contains no nitrates, phosphates or heavy metals.

It can be an interesting alternative since it is acidic, and will not cost you anything.


However, you should avoid using rainwater if it has not rained for a long time, and check that the roof and gutters do not contain any toxic substances for your fish.


It will also be necessary to filter the water with activated carbon to remove dust and other harmful substances.

In the long run, it is necessary to see if it is interesting at the budget level… not sure…


Spring water or well water

While walking in the forest, you could discover small acid springs. However, you will have to be careful because some springs can be contaminated by nitrates or even some heavy metals.


The same is true for wells and a simple aquarium analysis of pH, HK and GH is often not enough to determine if the water is suitable for aquarium use or not.


Osmosis water

Osmosis water is the most commonly used water in aquariums to acidify tap water.

It is however important to take some precautions.


RO water is nothing more than tap water that has passed through the osmosis machine and has lost almost all of its minerals in the process, making it pure water.


It then becomes a water with a zero KH, which makes it a totally unstable water used pure.

It is therefore often recommended to use it by mixing it with tap water, either 1/3 osmosis water and 2/3 tap water, or half and half.


Be careful, the proportions are totally different according to the tanks, it is therefore necessary to test to obtain the adequate parameters in order to determine the percentage to be cut and to stick to it during the weekly maintenance.


It is always possible to try to obtain the right parameters by testing small volumes in order to determine the percentage to cut.


Some experienced aquarists use pure water and remineralize it to the desired parameters with mineral salts (ex: Preis salt).


Bottled water

Bottled water has the advantage of being non-toxic, but also of having been thoroughly analyzed for minerals.


Depending on the species in your aquarium, you can choose your bottled water. The only drawback is the cost, especially for large volumes.

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