1. You should always thoroughly research the type of aquarium you are going to be setting up before you purchase it. Make sure you have the proper gallon capacity and shape that will fit in your home.
2. Having a quarantine tank on hand is a very good practice to use if you frequently buy new fish. The quarantine tank will weed out any sick fish that could possible get into your aquarium and cause harm to the other inhabitants.
3. It is never a good idea to add shells from the beach into your aquarium. Introducing shells raw from the beach can add harmful bacteria and potentially new creatures to the aquarium.