Skip to Content

Can Platies Live in Cold Water? (4 Tips to Maintain Tank Temperature)

Can Platies Live in Cold Water? (4 Tips to Maintain Tank Temperature)

Share this post:

This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Fish tank enthusiasts always hear a common question: “Can platies live in cold water?” In other words, can you keep platies in an outdoor pond or in a tank with no heater?

Read on for answers to these questions. This article also outlines the ideal temperatures for platies and lists ways to help your platies thrive in any water temperature.

What Is the Ideal Temperature for Platies?

Platies are tropical fish that typically thrive in warm water between 70 and 80°F. Therefore, you should try to maintain this temperature inside your tank.

How to Maintain the Tank’s Temperature

Fortunately, there are ways to ensure your platies live in ideal tank temperatures. Here are some:

1 – Install a Tank Heater

Perhaps, a tank heater is the first option that comes to mind, but which type works best?

There are five main types of tank heaters you may install. The best one depends on your budget, tank size, and your typical room temperature.

Here are the five types to choose from:

  • Filter heaters are the most common. They’re basically filters that heat water as it goes through them.
  • Hanging heaters hang above the tank with the heating element dangling in the water. They’re ideal for beginners and freshwater tanks.
  • Submerged heaters are kept near the water filter to heat the water as it comes out. It’s best for keeping your water temperature consistent.
  • Inline heaters also heat the water coming out of the filter. It’s commonly used in tanks with large fish.
  • Substrate heaters are made of wires that go under the tank. This type isn’t very popular due to its high cost.

2 – Put in Direct Sunlight

To maintain your tank’s temperature, place it under direct sunlight. It’s the ideal way to provide natural heat.

However, you should be cautious. Otherwise, the sun might overheat your tank and harm your fish.

In addition, sunlight may accelerate the growth of algae. Thus, you need to find ways to eliminate this problem.

3 – Use Lighting

You can also install a good lighting system that lights up your tank and heats its water. To provide your platies with the right temperature, you should choose the right type of light.

While Incandescent light emits the most heat, it might not be the best lighting option for your aquarium.

On the other hand, LED lights can be a good option, but not in this scenario. They have a low heat output. Instead, we recommend fluorescent lights.

4 – Insulate the Tank

Insulating your tank is a traditional way to maintain its temperature in winter. Simply, wrap your tank all over with insulating material, such as:

  • Newspapers
  • Towels
  • Cardboard
  • Styrofoam

That way, you keep your tank warm. Remember that you also need to cover the top of the tank to maintain its warmth.

Keep in mind that whenever you open the wrap to check on your fish, you let some of the heat escape. So, don’t fall for this urge.

Can Platies Live in an Outdoor Pond?

Whether your platies can thrive in an outdoor pond depends on your area and the season.

Since platies naturally live in tropical weather, expect them to live perfectly well in an outdoor pond during the summer and spring.

However, when it’s winter, your platies most probably won’t survive. That’s because the temperature drops below 60°F in almost all areas in the US. That’s way below the average temperature for platies.

Another important consideration is the consistency of water temperature. Use a thermometer to make sure that your water temperature doesn’t fluctuate. Platies can’t survive in changing temperatures.

What Happens to Platies in Cold Water?

Platies don’t function well in cold water. In fact, they might be harmed in different ways, such as:


Cold water can make your fish more prone to disease. That’s especially true if the temperature of your tank water fluctuates. Unfortunately, diseases may lead to your fish’s death.


Low water temperature can cause stress to your fish, which has a major influence on the platies’ behavior. Stressed-out platies can get aggressive. This may lead to severe fights ending in deaths.

Improper Growth

Cold water affects the metabolism of platies. It may lead to drastic results, such as stunted growth. In some cases, platies can’t reach their full size in cold water.


Platies are known for their high activity. However, they can’t maintain this type of energy in cold water. Instead, they show less activity and even weakness.

Final Thoughts

Can platies live in cold water?

No, they can’t. Platies are tropical fish that require their water to be between 70 and 80°F. Therefore, you need to heat your tank water. That can be done by tank heaters, direct sunlight, good lighting systems, or tank insulation.

As for outdoor ponds, your platies can thrive there during summer and spring, provided there’s warm weather and stable temperatures.

Share this post: