Don't drink the pool water.
Don't even put it in your mouth and spit it out.
To do so could lead to a recreational water illness, said Eileen Usman, the district epidemiologist for the West Central Health District.
"Just because a pool is clean, just because it has the proper chemicals, doesn't mean you can't get sick," Usman said.
She explained chlorine and other disinfectants do not instantly kill every germ in a pool.
The time has arrived when people will be spending a lot of time in pools and safety should be taken.
Recreational water illnesses caused by bacteria include skin, ear and respiratory infections, but Usman said the most common problems are gastrointestinal, primarily diarrhea.
The Centers for Disease Control and Prevention reported the number of recreational water illnesses has increased over past decade.
People bringing dirt into a pool hurts the effectiveness of the chlorine.
"It is important to shower with soap before entering a pool," Usman said.
Much of the contamination that makes people sick has to do with feces.
Usman said people should not swim if they have diarrhea. Everyone should wash their hands after using the bathroom or changing a diaper. Diapers should not be changed in the pool area where germs can rinse into the water.
The CDC says people should take a bathroom break every hour. Diapers should be checked even more regularly.
Usman said even if babies are wearing special pool diapers or swim pants, regular checking is important.
"There is still leakage," Usman said.
Swimmers should take notice if the pool in which they are swimming is receiving proper care.
Kristi Ludy is the environmental health county manager for the Columbus Department of Public Health, a division of the West Central Health District. Its responsibility includes local health inspections.
The department inspects public pools, including those at hotels.
"We don't do private pools," Ludy said.
She said there are several things for swimmers to check at a pool at which they are swimming.
"If it is a public pool, there should be the inspection grade posted near the entrance where it can be seen," she said,
A clean pool should have smooth pool sides. Tiles should not be sticky or slippery. If they are, there could be an algae problem.
No tiles should be broken.
"The water should be clear. You should be able to see any stripes at the bottom of the pool," she said. "You should be able to see the drain, You don't want someone stuck down there and not be able to see them."
The CDC says pool pumps and filtration systems make noise and you should be able to hear them running.
Though there are chemicals used in the water, a strong chemical odor means something is probably wrong. According to the American Chemistry Council, the smell comes not from chlorine but chloramines, chemical compounds that build up in pool water that is improperly treated. Chloramines form when chlorine combines with compounds found in perspiration, urine, saliva and body lotions.
The CDC recommends asking if the pH and chlorine levels at the pool are checked twice a day and if they are done at times when the pool is heavily used.
People should ask what specialized training staff members have.
Ludy said that in Columbus each public pool must have at least one certified pool operator.
She said there should be a telephone in the pool area that can be used in case of an emergency.
At a public pool, a deep area is considered five feet or more. "There needs to be a rope separating the deep from the shallow," Ludy said.
General rules for safety from the American Red Cross include surrounding the pool with a fence, not letting children swim alone and staying away from drain covers.
Other pool safety advice includes not using air-filled swimming aids instead of life preservers, no running around a pool, no diving, no holding someone under water, no swimming if lightning is in the area, and no electrical appliances near the pool.