How To Remineralize Distilled Water For Fish Tank? Explained

The quality of tap water in many regions leaves much to be desired, so sometimes aquarium lovers are forced to look for alternative methods.

One of the most common is the use of distilled water in the aquarium. This is the purest water, which contains absolutely no impurities, but is it suitable for an aquarium? how to prepare and remineralize distilled water for fish tank?

how to remineralize distilled water for fish tank

is distilled water safe for aquariums?

It is possible, but it should only be understood that the distillate is dead water, therefore, it should not be poured into the aquarium in its naked form.

It completely lacks hardness salts, which are necessary for both fish and plants, at least in minimal quantities.

Such water cannot be used without special water treatment. But if we consider artificially restored distilled water, then this is perhaps the best option, since you can create any parameters that are required for certain purposes.

The distillate is also almost indispensable when it comes to breeding demanding fish species.

distilled water for aquarium top off

What about substitutions, when starting an aquarium, it is necessary to use only distillate. But in both cases, the use of distillate with a set of necessary salts is a great opportunity to create an optimal environment in the aquarium for its inhabitants.

The only case when the distillate needs to be topped up in a clean, naked form, without using remineralizes, is topping up instead of evaporated water.

This allows you to keep the water parameters stable because pure H2O evaporates, and the salts remain, while the distillate dilutes everything to the optimum level.

distilled water pros and cons For Aquarium or Fish tanks

Using distilled water in an aquarium has both strengths and weaknesses. The main disadvantage is the cost of such water, and if the aquarist does not feel this in small tanks, then for large volumes these are quite large regular costs.

Advantages: distilled water good for aquariums

  1. Maximum degree of purification. No extra impurities.
  2. The ability to artificially create any parameters.
  3. The distillate, when topped up, maintains the stability of the parameters.
  4. In many cases, the distillate has a slightly acid reaction, which is excellent for most types of fish and aquarium plants.

Disadvantages: distilled water bad for aquariums

  1. Not every water that is sold under the guise of distilled is actually so. A real distillate should have a TDS of 0, but sometimes you can find “supposedly distilled water” with a TDS of more than 30 on sale. This is ordinary osmosis, and of poor quality.
  2. Price. This is the most expensive water you can find. It is also possible to produce it yourself, but gas or electricity bills will be impressive.
  3. The need for artificial mineralization. Moreover, household mineralizers are not suitable, special ones are needed for the aquarium, which also cost a lot of money.
  4. Often, in the production of distillate, equipment made of copper is used, therefore, copper ions are often present in distilled water, which have a toxic effect on arthropod inhabitants (shrimps) of the aquarium. Therefore, it becomes necessary to use special air conditioners.

Using distilled water in a small herbal or shrimp tank is one of the best solutions, but it is too expensive for a large tank.

how to remineralize distilled water for fish tank?

Before pouring distilled water into the aquarium, special attention must be paid to Aquarium Water Treatment.

You should make sure that the purchased water is really distilled, this can be done using a TDS meter or tests for total and carbonate hardness.

If you have demanding species of shrimp (caridina) in the aquarium, then it is worth using a conditioner that binds all heavy metals to get rid of copper ions.

Use a mineralizer that matches the type of aquarium:

Type of aquariumEssential Salts
NauticalSpecial synthetic sea salt
HerbalistGH+ or KH+/GH+
Sulawesi Shrimp and Snail AquariumpH+

Let the mineralizers dissolve for several hours, check the parameters, and if they are suitable, you can pour water into the aquarium.

Enhanced aeration in a container with distilled water and a mineralizer accelerates the process of salt dissolution.

when to add distilled water to aquarium?

distilled water should be added weekly with regular changes.

The % of water change depends on the type of aquarium, but most aquarists change about a third of the volume of the tank once a week.

This helps to remove accumulated organic residues and reduce algae-causing nitrates and phosphates.

You can pour water directly from the tank, the main thing is that the parameters of the distillate and the parameters of the water in the aquarium are approximately the same so that the fish are not stressed.

In the hot season, pure (not reduced) distillate should be added more often, since the evaporation process occurs much faster than in winter or late autumn.

what is the best water to use in a fish tank?

No matter how good distilled water is, but its regular use will significantly hit your pocket. Therefore, it is worth paying attention to more budgetary water, which has similar properties. It is either osmotic water or bottled.

what is the best water to use in a fish tank

Osmosis involves the installation of relatively expensive equipment, but, in the end, it will come out cheaper than using distillate. This is especially true for large aquariums.

Bottled is good because many unscrupulous manufacturers sell the same osmotic water, but this is only good for aquarists. The main thing is to find such water.


The use of distilled water is quite expensive, but it allows you to achieve any desired results. Soft water, which is remineralized distilled water for fish tanks, is the key to the rapid growth of aquarium plants and the normal development of fish.

Also, with its help, such demanding fish as discus, angelfish, and red neon are bred. But for long-term use, it is still worth switching to water purified by reverse osmosis. According to its properties, it is practically the same distillate, but it costs several times cheaper.

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