Aquarium water temperature is an important factor in the health of your fish. All fish have an ideal temperature range where they will thrive. Yes, I said range – in most cases, your fish do not need an exact temperature.

This makes sense, in the wild, there is no aquarium heater ensuring that the water temperature remains constant. Rain, hot summer days and cold winter nights all work together to ensure that fish in their natural environment do not experience the same temperature for too long.

In fact, freshwater fish can experience daily temperature swings of 30°F or more. Even in the reef environment, the daily temperature swings from 68-90°F (20-32°C).

So if this is the case, then why do we insist on keeping our aquariums at a constant and stable temperature?

Well, it all comes down to how fast the temperature swings.

Because oceans and rivers contain so much water, it takes a long time for the temperature to rise or drop. Your aquarium, on the other hand, is not so lucky.

The small amount of water can quickly heat up or cool down based on the temperature outside the tank. It is this rapid change in temperature that is the problem.

The life of your fish depends on your ability to maintain the correct temperature.

So in your home aquarium, the goal is to maintain a water temperature that is within the preferred range of your fish, invertebrates, plants or corals.

Don’t have fish? You’ll still need to keep an eye on the temperature. Invertebrates, corals, plants and algae have all been observed to be negatively influenced by temperatures outside of their preferred range.

Even the beneficial bacteria in your aquarium are affected by water temperature. The preferred range is 65-85°F (18-29°C). At 95°F (35°C), bacteria die, which can lead to ammonia spikes. Lower temperatures cause the bacteria to become less active and can even make your aquarium take longer to cycle.

Rapid or Frequent Changes

Experts disagree about the need for a constant temperature that never wavers at all. Some feel that fish that do not experience the typical day/night temperature changes that occur in nature, develop a less robust immune system, and therefore are more susceptible to disease. Others feel that all temperature changes are stressors that can lead to poor fish health.

However, all experts agree that rapid and significant temperature changes, as well as frequent temperature changes throughout the day, are stressful for fish.

These types of sudden changes or frequent water changes may occur for a multitude of reasons, including…

• Tank located next to a door or window • Tank in direct sunlight part of the day • Large water changes • Lighting that produces heat  Faulty heater

The life of your fish depends on your ability to maintain the correct temperature.

Don’t have fish? You’ll still need to keep an eye on the temperature. Invertebrates, corals, plants and algae have all been observed to be negatively influenced by temperatures outside of their preferred range.

Even the beneficial bacteria in your aquarium are affected by water temperature. The preferred range is 65-85°F (18-29°C). At 95°F (35°C), bacteria die, which can lead to ammonia spikes. Lower temperatures cause the bacteria to become less active and can even make your aquarium take longer to cycle.

 

Acclimating New Livestock to Your Home Aquarium

When introducing livestock into a home aquarium, acclimation is an important step that everyone should follow. Acclimating is the process of slowly introducing fish, coral, or invertebrates into a new aquarium and adjusting them to your aquarium’s water.

This is important because differences in water chemistries can stress aquarium livestock if they don’t have enough time to adjust. The process varies depending on the sensitivity of the organisms you are acclimating. 

Generally you will receive new aquarium livestock in a bag or container of water. To acclimate your new pet, let the bag float in your tank. This helps the water in the bag slowy adjust to match your aquarium’s temperature.

To ensure proper acclimation, use an accurate thermometer to carefully monitor the temperature of both the aquarium water, as well as the water in the bag or container. Make sure there are no sudden spikes or drops in during the process.