Why did my plant die?

Hey everyone, first time grower and poster.

I just built a closet grow box that can hold between 6-8 plants and allows them to get around 3 feet tall. I put one plant in there last week just to do a test run and I seem to have run into problems.

Im running a 400w in the box with a vent fan. The plant looked fine until about two days ago when i stopped running the vent, I noticed that without the vent running the temp went up to over 100 degrees. last night i left the door to the box open and that seemed to keep the temp around 80 but this morning the plant was pretty much done for.

could the two days of heat be its only problem? I included a picture i took two days ago before the temp rose and one from this morning.

Other things to note. I have been watering the plant once a day with alaskan fish fertilizer 5-1-1. the light has been running 18 on 6 off. and before two days ago the temp was always between 76-83 degrees.

yea thats how mine looked exactly thats a heat problem

why did you turn the vent off, keep it going 24/7.

ok cool, I thought that would be the problem, but not having prior experiance i wanted to make sure. I stopped running the vent because i need an extension cord to run it, bummer deal that a plant had to die over it. thanks guys

it might not of died. I've brought worse back. It looks overwatered to me as well. You need to make sure your letting the soil dry out enough for oxygen to get to the root system. Also I wouldn't suggest fertilizing every watering, Id shoot for every other.

definitely don't water every day. you can get a moisture meter at home depot for $8, it can tell you ph of soil as well. good luck dude. i have an indoor 4x4x6 room with 600w hps. but my light has a 6" hood that i converted a 4" blower through. i got hooked up through another buddie who grew, i see it as the only way to go. those hps get hot man! good luck!

yea 90 degrees and up is way to hot for plant man so its deff heat related and i agree with the guys with the watering advice too what is the temperature with the vents on..?

kepe the vent going, it looks 2-3 days away from being ok again.

REDRUM

was a horse....