On one end of the spectrum opt for a fully natural space. In these, the biological processes are left to their own devices, using plants and pond organisms to keep the water at its best.
Alternatively, choose a fully equipped model that requires minimal maintenance. These types are fully fitted with high-performance systems with regular cleaning by a robot.
Spending time in your own swim pond provides you with a safe place to swim outdoors, engaging with nature as well as benefiting skin and exposing you to healthy nutrients like vitamin D.