Help me please someone!!

My plant is about 6-7 weeks old. I noticed about 2 days ago that almost all the leaves are starting to go brown and then dry.
Even though the room temp. is a bit high (38 Cel. or so) they were doing fine until recently. I thought it was magnesium deficiency so I added a bit of empson salt dissolved in water but I can't see any improvement.
My ph is about 8 (embarrassing)

How can I correct all this?

Pictures before and after are added

anything over 30c is gonna kill em. 38c is ridiculous! Try and set fans etc up so it stays around 25 if poss

flush the hell outa them, your p.h. should be 5.7 - 6.3 no higher no lower.

will address these straight away. it should have been showing buds already so now i know why.

hope you can save them dude, btw your Ph can be up to 7 without problems but try n keep it a bit lower

Combo of several things...Nute burn, Heat, High PH all = recipe for disaster.
No more nutes for now
PH the water
Lower the temps and provide good air circulation

should i flush them out with distilled water or is pipe water left to stand for 24hrs ok?

check the Ph first and then its good to let it stand for 24 hrs to de-chlorinate the water

ph is embarrassingly about 8

yeah you said earlier. You definately need to lower that ph first. I use a few drops of distilled white vinegar but careful not to use too much of it. Fill up a bin or something and add the vinegar, stir it right up and check ph again. Then leave for 24 hrs. Stir it, check it, and if its ok then go ahead and water