Since the storm, Jules Passwater, who owns a pool service business, said work has been busier.
"Yesterday I spent about two hours at a pool because it had some clogging and the algae already started to build up, so by the time I got there to clean it, it was definitely in need of some care," Passwater said.
Passwater said Hilary blew dirt, foliage and other runoff into pools making them dirty and in some cases unsanitary.
PHOTOS: Images from Hilary, a rare SoCal tropical storm
"Some people have a lot landscaping. They may have soil that's close to the pool that can runoff into the water and actually affect the chemistry, the PH, and sometimes it can be contaminated," she said.
Passwater suggested checking the skimmer and skimmer baskets in the pool to see they're not clogged.
Also, Algae is a good indicator that sanitizer levels may low, she added.
She recommended testing the water's sanitizer chlorine and PH levels before jumping in.
"Anytime there's algae in the pool, it may not be sanitized sufficiently, so it's really not a good idea to get into a pool that's murky, that has algae, because it may not be sanitized properly," Passwater said.
She said maintaining a home pool is a lot of work, so the easiest thing you can do is get a testing kit so you can test the sanitizer and PH levels.