What are the Ideal Water Parameters for Guppies?

What Water Is Safe For Guppies

Guppy Tank Conditions: The Ideal Water Parameters

Guppies (Poecilia libestes reticulata) are one of the most popular fish species for beginners.

They are quite hardy and can easily adjust to fluctuations in water conditions than most species of fish.

Guppies are endemic to the fresh and brackish waters of the Amazon River and on several islands in the Caribbean.

It is one of the smallest live-bearing fish species, with females reaching only 2.5 inches and males slightly smaller.

In order to ensure that guppies thrive well under tank conditions, there is a need to mimic as much as possible their Amazonian habitat.

You can achieve this ideal environment by focusing on the important water parameters.

Water Parameters for Guppy Fish

  • Water temperature: 72°F to Max 82 °F [ 22°C to 28 °C ]
  • pH of Water: 6.7 to 7.9
  • Water Hardness (dGH): 8 to 12.
  • Ammonia 0 ppm or Nil
  • Nitrites 0 ppm
  • Nitrates 10 ppm maximum.

Basic water chemistry

There are three important parameters that should be taken into consideration when creating ideal conditions for guppies.

These parameters are water pH, temperature, and water hardness.

Maintaining pH Levels

pH is a measure of the acidity or alkalinity of a substance.

It is measured on a scale of 1-14 with 7 being the neutral pH.

Acidic pH refers to values that are lower than 7 while figures higher than 7 are alkaline or basic.

Ordinary tap water usually has a pH of 7.

However, the water in your tank has different pH because of the chemicals dissolved or suspended in the water.

Different species of fish thrive in different levels of Ph. While guppies do best when pH ranges from 7-8

Water hardness

Although water hardness is a crucial parameter for the survival and growth of guppies, many aquarium owners often neglect its significance.

Fish thrive in a specific range of water hardness, and when these levels are not achieved, it can cause stress and possibly death.

Water hardness simply refers to the total dissolved minerals in any type of water.

Hard water is the term used when there is a high level of dissolved minerals, while soft water has a low mineral level.

It is important that you appreciate the relationship that exists between your water pH and hardness.

Hard water usually has high pH because the minerals present act as buffer thereby reducing the amount of acid (pH) in the water.

The ideal range of water hardness for guppies is GH 8-12.


Besides Water Ph and Hardness its temperature is equally important for your guppy and tank mates.

Fish and live tank plants can only tolerate a limited range of temperature or water variations.

Water temperature is consistency is pretty important here, Sudden changes in water temperature can often result in health issues and diseases over time.

For Guppies, the ideal water temperature range is between 10-29 °C (50°F – 85°F);

Guppy fry thrive best at 25.6 °C (78°F)

Juvenile at 24.4 °C (76°F)

For adult Guppies 23.3 °C (74°F)

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