Here are the steps to build a fish tank:

1. Planning the design: Draw out and design a thorough plan on what you want the fish tank to look like. Choose the size and volume of the aquarium and what type of shape you want the fish tank to have.

2. Choose your panels: You will need to choose the glass panels for your aquarium. You can choose from tempered glass or annealed glass.

3. Align the panels: Once you have your glass panels, align them according to your design.

4. Apply the silicone: Apply silicone sealant to the edges of each panel where they meet.

5. Push the glass: Push each panel together firmly so that they stick together.

6. Fix any mistakes: Check for any mistakes and fix them as needed.