A very viable alternative to this is the use of a Salt water chlorinator which produce chlorine by splitting up Salt into Chlorine and other substances which convert back into salt after a couple of minutes. As a result you have only salt water in your pool while the chlorine kills all the germs where it is not dangerous for the swimmer (in the pipes of the pump house) and converts back to salt before it enters into the pool again.
There are of course a few other alternatives such as Ionization - where Copper and silver ions are produced, which destroy the cells of algae and bacteria. OR Hydrolysis oxidation - where water is split up into Ozone, OH, Peroxide and Oxygen (which are in there pure form very aggressive and kill algae and bacteria) before converting back into pure water when returning back to your pool.
But our preferred method and one that is in very common use in the Algarve is the salt water system and on rarer occasions in combination with a UV (Ultraviolet) lamp for extra assurance.