cold nights ?

yous 400 watt. nights are getting cold. when lites are off. food organic. leaves turning maroon and yellow. food earth grow and other good stuff. growing 10 years indoor. Is the cold blocking nutes ???

depends on how cold. It stress's them off. Stress= less growth =less nutrients= less yield.
18c+ is what i recomend.
Stop your outtake and use a dehum. You will thank me later.
think of your room as a semi sealed room.

cold temps that make it turn purp stop or slow the chlorophyl down thus stops or slows foods processes....makes for a weeker bud in the end.