i noticed the stem is starting to get brownish i read around afew places and some places said it was overwatering others said it was some type of bacteria and another place said Unstable Temp. at night my temp is from 76 - 81 F and when the sun is out my temp is at 78 - 84 F i cant manage to get it to a stable temp at all times because i cant have my AC running during the day. electric bill comes at $400 a month before i even started this grow. i only have control over the night temps should it be colder ? or should i leave the ac off to try and par it with the day temps?

I closed off the front and top half of the rack with cardboard covered with tinfoil now the part that is covered dont reflect light to the closet door not shure if that is helping any or if i even should have done that will see if i noticed any changes