Hair Care when Swimming: A Tip on Water
This is a classic error because water on its own is a really useful first cleaning step. Rinsing hair with water for 2- 5 minutes before adding shampoo allows any water soluble chemicals that you may have picked up from the pool to be rinsed away.
For example people (especially kids) do wee (pee if you are American) in the pool meaning urea from the urine and chlorine can react to form acids. Yes swimming pools do have filters and a well maintained one will also have regular pH checks, however, end story is, as long as it is a public pool more than likely someone has pee'd in it.
Anyway, back to my tip, these acids tend to be very water soluble (otherwise you would see solids in the pool water......blech...ok that is disgusting!). Spending those 5 minutes just rinsing the hair allows any water soluble muck to get access to fresh water and be rinsed away. This tip does apply too when washing your hair in normal circumstances. You may also notice that you will be able to use less shampoo with thoroughly wet hair.
Hope this helps!