1. It is generally a good practice to purchase the largest aquarium that you can actually afford. A larger aquarium will be less susceptible to quick changes in the chemistry, and will offer much more stability.
2. Wrasses are very lively fish, and love to jump. You should always have a well secured lid when keeping wrasses in your aquarium.
3. You should always stay up to date on the new and exciting practices for fish keeping. Subscribe to several news letters to keep up to date. If you like to read, go to your local library and get some books on fish keeping.