Introduction of new fish

🐠 How to properly introduce discus fish into an aquarium – Step-by-step:

When transferring discus fish after transport, it is especially important to acclimate them gently to the new water temperature. As cold-blooded animals, discus are sensitive to sudden temperature changes – this can lead to stress, organ damage, or even death.

🌑️ Preparation: Adjusting the temperature in the aquarium:

Since transport water can cool down significantly in cold weather, the aquarium temperature should be lowered slightly before the fish arrive. This avoids too large a temperature difference. Recommendation for aquarium water temperature: When outside temperatures are above 10 degrees, lower the aquarium temperature to 24 degrees, and when temperatures are below 10 degrees, lower the water temperature to 22 degrees.

πŸ” Measure transport temperature:

Depending on the weather, the fish usually arrive at a temperature between 17β€―Β°C and 24β€―Β°C. To know how large the temperature difference is, you should measure the transport water:

  • Ideal: with an infrared thermometer, also available in our shop.
  • Alternatively: place a normal aquarium thermometer in the thermobox (between the bags) for 5 minutes and then read it.

πŸ•’ Transfer depending on temperature difference:

βœ… Temperature differenceΒ 

up to 2β€―Β°C:

The fish can be placed directly from the bag into the aquarium – without the transport water! A slow acclimatization is not necessary in this case.

⚠️ Temperature difference 

more than 2β€―Β°C:

Then the temperature must be adjusted carefully. The following method is suitable for this:

  1. Keep the bag closed – do not open it!
  2. Fill the thermobox halfway with aquarium water (the bags remain inside).
  3. Wait 10 minutes, then fill the box almost completely with aquarium water.
  4. Wait another 10 minutes, then check the temperature.
  5. Is the difference still over 2β€―Β°C? Repeat the process until the difference has dropped to 2β€―Β°C or less.
  6. Then open the bags and carefully transfer the fish into the aquarium by hand or with a cup.
  7. Do not put transport water into the aquarium!

❗Important note:

Never add aquarium water to the bags to "equalize" the water parameters. This can endanger the fish. Due to breakdown products in the transport water (e.g., ammonium) and rising pH, toxic ammonia can form – which damages the gills and can be fatal.

⏳ Time guideline:

  • For up to 4β€―Β°C temperature difference: approx. 30 minutes acclimatization
  • For every additional degree: plan an additional 20 minutes

➑️ Better to acclimate slowly than too quickly – this protects the animals' organisms.

βœ… Conclusion:

Discus fish require special care when being introduced. Not the water parameters are critical – but the temperature. Those who adjust it slowly and safely protect their animals from unnecessary stress and health risks.

With this method, the start in the new home will be safe – for healthy, strong, and long-lived discus fish.