If its not clean people might get sick.
soap
To keep your swimming pool clean you will need a filters and a water pump. A vacuum would as be a good idea.
*clean chlorine.
Chlorine is generally added to swimming pools and other water attractions in order to keep the water clean. Doses of chlorine typically come in small tablets.
to keep the water clean and kill germs
If you are swimming in clean, chlorinated water this would be safe. If the water is not very clean, then there is a risk of exposing your sore to an infection. Personally, I would wait for the sore to heal.
Clean water Kills Bacteria in swimming pools
Dirty water verses clean water
HOCL or hypochlorus acid
It is important who will try to clean it
Depends where you are swimming. Swimming in a lake or other naturally occurring body of water wouldn't be recommended because of the various bacteria that live in that kind of water. on the other hand, swimming in a clean pool should be fine as long as your piercing isn't showing any signs of infection already and you make sure to clean it thoroughly afterwards.
Mosquitoes will hatch in swimming pools if the water is stagnant, However if the water is regularly run through filtration and chlorinated this should not be a problem.