Why Did It Dry Out So Fast?

idk how it happend but my plant went from looking amazing and full of life and when i woke up it was fully dried out to the point of it crumbling, what am i doing wrong i i water everyday and this happend. i am growing a a homemade pc grow box Please tell me what i did to prevent it next attempt

btw yeah i know i ask alot of questions

thank you

hey,,what as in heat stress,,the leaves yellowed and crispy to the touch?.
you have temp readings? get a thermometer if you dnt have one. And RH meter,
On a side note, did the plant need water every day, or were you just watering. What medium were you in, soil?, how old was the plant,size,what sort of light do you have in the pc?
were you using nutes, everyday, and if so what are they and there N-P-K, etc.

Yeah not having a go at you ,so dnt take offense,,but its advisable to give as much info as possible so people get the complete pic, so we can sort out the problem.

take it easy.

no nutients, cfl, and about 2 weeks old for that one plant i just uploaded pics i dont think it could be heat stress because its been the same the entire grow but if i need a thermometor then i ll get one

It doesn't need water every day. Only when the soil is dry about 1/2 inch under the surface. It may need to be transplanted if the soil is drying out quick also.

Aye,, just saw your snaps,, well that soil looks too wet,,so try find the temp in that pc,then adjust your vents accorrding,and a thermometer is a must in my view,, well gutted though,
so over night you say this happened? are you on 24hr lights or 18/6? also do you have good airflow in and out,,looks heat streesed to me, how far from the cfl is or was it? and in such a small space air exchange is a must, if theres no air flow the air becomes bad/stale and has to be changed.so what your vent sitrep?
take it easy.

yeah just as a side note,and lots will disagree and some agree it a good idea to use those plastic cups ,BUT, honestly roots need darkness to live,light is bad for them,(damaging and killing them) so when the roots start to come up to the side of the pot they would grow in the dark period(if there is one) around the side and then be damaged/killed back and wont grow round the side as they can feel the light coming through the clear plastic.
if you see what I mean. so yeah it maybe a good idea but kinda rookie mistake in my view, as root need the dark and the sides of the cups wont stop light going through,so roots wont grow or will and the die back when the lights go on.
small 4 inch pots are pennys for ten of them.
So are there roots at the side of that dried out plant? ,maybe thats whats done that,root die back,,if theres no roots thats cause the plastic is see through.
A plant that size would be becoming root bound in a 4 inch pot(not root bound in a bad way, enough to make transplant easy.)

anyhow,take it easy.

I believe your problems are "several" which have accumulated......overwatering is the first and certainly most growers fastest way to killing seedlings.....little to no air exchange to control heat buildup is always gonna hurt ......

Water every other day, make sure you get some run off (water draining out the holes in the bottom of the pot), Check the waters PH (5.8 - 6.4) cover the cups/pots with black tape so no light gets to the roots, start feeding on weak nuits (not miricle grow) and keep an eye on temps - STELTHY