Pros
Day to day work is going to depend on how the franchise owner runs the store. Retail is simple and for the most part is focused on being able to make sales on pool chemicals, cleaners, pumps, heaters, and other fancy pool equipment, as well as communicate to customers in a way that helps them understand pool stuff. Decent pay in the median range of 12-15 dollars an hour. Being a pool tech requires the ability to follow directions, not slack off, and at the core just keep pools clean and clear of algae. Rather than working in store you are usually working outside all day. The amount of pools you have to clean in a day varies as well as the services you have to perform at them. Better pay that usually can include some form of commission depending on how the store operates, 500 - 600 dollars a week + commission.
Cons
Individual stores suffer from being run poorly or having bad staff who don't know what they are doing. They advise customers incorrectly or sell them the wrong pool stuff and can hurt the overall image of a store and other surrounding stores.