The Weyerhaeuser King County Aquatic Center is going to be a very busy place.

The U.S. Open swim championships kicked off on Tuesday and will continue through Saturday, hosting swimmers from all over the world.

Then starting on Monday, the center will play host to the U.S. Swimming Speedo Junior Nationals.

Two-time Olympian Margaret Hoelzer, who trains in Federal Way with King Aquatics, is scheduled to compete in the 100-meter and 200-meter backstroke.

The pool is known as a fast one and already, that is holding up.

On the first day of competition, meet records were broken in the women’s 200-meter breaststroke by Katlin Freeman and Ashley Wanland, who both got under the previous meet record of 2:25.80.

In the men’s 200-meter breaststroke, records fell to Rober Lovelace and Aaron Opell, who both made it below the mark of 2:10.67.

On the second day of competition, four meet records fell. National Team members Nick Thoman of Cincinnati, Ohio, and Nick Brunelli of Mansfield, Mass., lowered their meet records.

Jack Brown broke a meet record in the men’s 400 IM with a time of 4:12.58.

Erika Erndl also set a meet record in the women’s 100-meter free with a time of 54.59.

The Seattle Times has also reported that California’s Jessica Hardy, who was banned from swimming after a positive drug test at the Beijing Olympic Trials, will be returning to the sport, swimming the 100 freestyle at the U.S. Open championships.

Hardy was originally given a two-year ban, but that was reduced to one year after a panel ruled that she tested positive for clenbuterol, accidentally ingested through a nutritional supplement. Her Olympics career is still in question, as it has not yet been decided if she can compete in London.

Hardy claimed a silver in the 100-meter free with a time of 55.07.

Olympic silver medalist Elaine Breeden brought home a gold on the first day of competition for her swims in the 200-meter butterfly with a time of 2.08.07.

Individual session tickets for the U.S. Open for children under age 12 are available for $5, and $10 for adults. A one-day pass can be purchased for $15, while an all-session pass is available for $50. Prelims begin at 9 a.m., and finals begin at 6 p.m.