HELP PLEASE DWC

I am having troubles out of my DWC ak

5 Gallon dwc. Advanced notes 3 part formula. Extreme leaf curl and very small new growth...could this be caused by one cold night?

Are you filling your bucket up too high with water ? Leave an air gap for the roots to breathe bro

I use 3.5 gallons in 5 Gallon bucket. Leaves about 4 inch gap from netpot..added a heater to the room and it perked right up..it got way too cold night before last..thanks