Question

what are the step by step methods that are required in adding Na2CO3 to a tank of water ?

Answer 1

You must be kidding?

1. Secure tank.
2. Fill tank with water.
3. Unscrew the lid on the jar of Na2CO3.
4. Remove some Na2CO3
5. Sprinkle in tank
etc etc.
I'm sure you didn't want this but that's what the question asks.