Expansion

In addition to giving you more space to decorate, each expansion increases your maximum number of fish, bottom feeders and plants by two. You can expand your pool by collecting Friendship Shells from your neighbors' pools, at a limit of one shell per neighbor every 20 hours.

1st upgrade: (Small Rock Pool): 50 Friendship Shells or 200 MC

2nd upgrade: (Medium Rock Pool): 150 Friendship Shells (+ Level 10) or 300 MC

3rd upgrade: 350 Friendship Shells or 300 MC

In order to scroll across your tank, move to the side and an arrow will appear or click on the blue rectangle at the bottom of the game screen and drag to change your view.