Hi
@Weezy90 !
If I plugged the lights completely, they actually shut off completely, immediately. Probably the extension cord leaked a little bit of power even the timer was on off-mode.
I solved this problem by setting a timer before the extension cord, and I switched to a better timer.
Anyway it wasn't about power consumption. The problem was that there was any light at all at night time, which is a big no no for the plants, from what I've learned.
Thanks for the answer though!