How to choose between "S" and "F" modes:

"S" mode: If you haven’t cleaned your pool for a long time, or your pool is very dirty, feel free to use Standard Cleaning Mode.
“Standard” mode: gently switch to “S” mode. Do not use excessive force. (The indicator will light up in white for 3s.)

"F" mode: If you clean your pool regularly, feel free to use Fast Cleaning Mode for daily cleaning.
“Fast” mode: quickly switch to “F” mode. (The indicator will light up in green for 3s.)