Adding another pair

Fig: 5.1

We added another pair of Tetra within the first few days. Since they are schooling fish, it is usually recommended in groups of five or six. The dynamics of the whole tank changed! They got along well with each other, there was less fin nipping. It seemed as if they were doing well.

A month later, we wanted to introduce another variety of fish - Platy.

We bought five (Sunburst wag Platy) and added it to our tank. They were amazing. Beautiful, colored.

Introducing new fish-

• Turn off the lights, Float the bag for about 15mins.
• Let the temperature of the  water in the bag and the tank equalize. 
• Using a net, transfer them into the tank, one by one. The new ones will try to look for hiding place as soon as they get in. The tetras were busy fin nipping. By next day morning we found most of the new ones had their dorsal fin nipped :(
• Three days later, we lost one platy and one tetra. 

The ammonia and nitrite levels increase. Fish undergoes stress, adjusting in its new home. At times bullied by the fish occupying the tank prior to its arrival. As a beginner we are so excited to add new fish, that we do not take into account the size of our tank. If you do the math right, 5 Tetras and 5 Platys would need a tank size 22.5 Gallon. A thumb rule, (size of the full grown fish) X (number of fish). 

Tetras usually grow up to 2" and Platys up to 2.5". 

We returned the platys and added one more tetra and left it at 5 tetras in the 15 Gallon tank.