The Fish Emporium sells many different kinds of fish for the Virtual Tank, but it also sells upgrades. Upgrades are found in the bottom-right store slot and must be purchased in order as there are only one of each.
The Bubbulator allows players house up to 20 fish at once. It costs 20,000 shells.
The Alien Attractor periodically attracts aliens, hence, which can be killed for blue conch shells. It costs 50,000 shells for a cumulative cost of 70,000 shells.
The food upgrade changes the flake food for guppies to vitamin-rich capsules. Fish need to be fed less often and they grow faster. It costs 20,000 shells for a cumulative cost 90,000 shells.