Ideal Water Parameters Preferred by Platy fish

While the platy fish is found in diverse regions ranging from Mexico to Belize, it needs to have specific water conditions to thrive.

What are the ideal water parameters preferred by the Platy fish? The list of water parameters includes temperature (68 – 78 degrees Fahrenheit), pH (7 – 8), ammonia (0 ppm), nitrite (0 ppm), nitrate (less than 40 ppm) and general hardness (12 – 18 dGH).

As the owner, it is your responsibility to make sure your pet fish stays happy and lives a long life. Continue reading this post as we explore different water parameters for the platy fish.

What are the Ideal Water Parameters?

As the owner of the pet, it is your responsibility and the pet’s right that you take good care of it. Be it the food, housing or the water, you need to make sure the pet (in this case, the platy fish) is happy and fully nourished.

The platy is a freshwater fish and it needs water conditions that are similar to its natural habitat. Following is a list of different water parameters that suit the platy fish.

  • Temperature: 68 – 78.8 degrees Fahrenheit
  • pH: 7 – 8.3
  • Ammonia: 0 ppm. No amount of ammonia should be present in the water.
  • Nitrite: 0 ppm. No amount of nitrite should be present in the water.
  • Nitrate: less than 40 ppm. The water should have a maximum of 40 ppm nitrate.
  • General Hardness (GH): 12 – 18 dGH (214.29 – 321.43 ppm). The platy fish prefers medium to hard water.
  • Tank Size: The platy fish multiplies very fast, so the tank should be larger than the required size. It should be large enough to contain at least 10 gallons of water.
  • Tank level: Mid dweller. The platy fish mostly swims at the mid-level in a tank.

Generally, the aquarium should be well planted, and it should be kept clean, especially during the breeding season.


Temperature is a vital parameter. The platy fish needs 68 to 78.8 degrees Fahrenheit to thrive in the aquarium. If the ideal range of temperature is not maintained, the platy fish will not be healthy and extreme temperatures may even lead to death.

You can check the temperature with the help of a thermometer. Accordingly, you can use aquarium heaters to heat up the water. On the other hand, you can use chillers to cool down the temperature of the water.


pH is a measure of acidity or alkalinity in the water. The platy fish prefers a pH range of 7 to 8.3. This means it will adjust well in water that is slightly alkaline. So, you cannot put the platy with another fish that prefers a different pH range.

How to measure pH level?

Aquarium test kits are the best option to go with for checking the pH level of your tank. Take a sample of water from the aquarium and add a drop of the testing solution. Observe as the water changes color. Now match this color with the color card that comes with the kit. This will tell you the pH level of the water accurately.

How to change the water’s pH level?

If the pH level is not suitable for your platy, go with the following measures to change it.

  • If the pH level is higher, add peat in the aquarium. This will decrease the pH level and acidify the water.
  • If the pH level is lower, add calcium (limestone) to increase the pH level. This will make the water more alkaline.

Platy fish are sensitive to changes in pH level. Therefore, do not make any rapid changes. Always make a maximum pH change of 0.3 within 24 hours.

Ammonia, Nitrites, & Nitrates

All three chemicals are a result of the fish waste in the aquarium. As the waste is broken down by the bacteria, ammonia, nitrites and nitrates are produced in the form of by-products. Initially, ammonia is produced as a result of platy fish waste. It is toxic to the platy and the bacteria dwelling in the tank convert it into nitrites. The nitrites, over time, are converted into nitrates. You can remove these 3 components by performing weekly water changes of 25% of the total water inside the tank.

General Hardness

When talking about the ideal water parameters, many platy fish owners forget about the hardness of water. But mind you, it holds as much importance as the other parameters do. Water consists of several minerals such as calcium, magnesium, sodium, potassium, etc. The amount of these minerals determines the level of hardness.

The general hardness of water depends on the level of minerals dissolved in the water. Water is said to be hard if it has high amount of minerals dissolved in it. While there are many minerals in the water, only calcium and magnesium make the water hard. On the other hand, water is said to be soft if it has lesser amount of minerals or if it is devoid of minerals. Lake water is mostly soft because it is not rich in minerals.

The platy fish prefers medium to hard water. The ideal range is 12 to18 dGH.

How to measure the level of general hardness?

In order to find out the hardness of water in your tank, use strip tests. These are strips that change color when dipped in water. Another name for this test is dip test. Before dipping the strip, take out a sample of water from the tank, never dip the strip in the tank itself. Now dip the strips in the sample water and you will observe that the strip has changed color. Compare this color with the chart that comes with the strip test kit.

How to change general hardness of water?

If the hardness level is within the ideal range, you can relax. However, if this is not the case, you need to take some measures:

  • If the water is harder than the platy fish’s requirement, you need to add in a softener to take out the excess minerals. Use a natural water softener available in the market. Many platy fish owners prefer Sera Super Peat.
  • If the water is softer than the platy fish’s requirement, you need to add minerals to increase their amount. The most common mineral you can add is a calcium rock. It will make the water hard and increase the pH as well.

Platy Fish Care Guide (Video)


While the platy fish has an adaptive nature, providing it with the ideal water parameters will only help it thrive in the aquarium and live a long healthy life. As a pet owner, it is your responsibility to ensure that your platy fish or any other pet is happy and healthy. Summing it all up; the temperature of the water should be maintained between 68- and 78-degrees Fahrenheit. The pH of the water should be kept between 7 and 8. Make sure there is zero levels of ammonia and nitrites in the water. However, you need to maintain a maximum of 40 ppm in the case of nitrates. The general hardness of the water should be kept between 12 and 18 dGH.

Related Questions

Can a platy fish be kept with other kinds of fish? The platy fish has a peaceful nature and it does not show aggression towards other fish in the tank or aquarium. So, you can place other fish in the tank without any fear. Usually, the platy fish gets along with Mollies, Swordtails, Tetras, Rasboras, Rainbowplaty fish, Danios, Angelplaty fish, Gouramis, Plecos, scavenger Catplaty fish and Bigger Tetras such as Black Skirts, Red Serpaes, and Silver Tips.

How to determine the gender of a platy fish? You can check the gonopodium under the platy fish to find out if the platy fish is male or female. Gonopodium is the rear fin (anal fin) under the platy fish’s belly. In the case of males, the gonopodium is long, flat and pointy. However, females have a fan shaped rear fin.

Does Platy fish eat its babies? Like other livebearers, platy fish does not lay eggs. It will give birth to baby platy fish called ‘fry’. As soon as the mother delivers the babies, it will start eating them as the platy fish do not have any maternal instinct. In order to avoid this, platy owners can darken the room of the platy fish to make sure she can’t see the babies. This will help keep the babies safe. You can also place plants in the aquarium. This will allow the babies to hide from the adults.

Can Platy fish be bred with another kind of fish?

Platy fish has a peaceful nature and can co-exist with a number of other species. In an aquarium, you will find platies living together with mollies, sword tails, etc. It is most similar to the swordtail platy fish. As a result, it is common for the platy and swordfish to breed with each other. Most aquariums have a hybrid of the two kinds rather than their pure forms.


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