Need Help QUICKLY

[Eyeless]

K i have a sativa plant...it was growing amazing..nice and healthy...but it looked like it was starting to get nutrient burn...so i flushed the pot....and then later that day the leaves started to curl down...harden/dry out and develop brown spots...

Pls help me if you have any advice on what to do

Pics from before and after are posted in my gallery

 

[PaRaLyZeD-420]

sounds like it could be nute burn, lower the amount of nutes for the next few waterings then see, whats your ph level? perhaps overwatering? give us all the info on the grow what method your using to grow? Give us everything you can and I'm sure one of the many helpful growers here can help you figure out what is wrong.
Peace P420

 

[Eyeless]

I am growing in soil (closet)..500 watt bulb...fan ventilation...was growing healthy as i said before...then when nute burn was suspected i simply poured water through the pot until in started running out of the bottom...then the next day it developed brown spots along the middle of the larger leaves...the tip cupped a bit and curled down. The leaves themselves seem to be a bit harder/dryer as well. The younger growth coming from the node at larger leave seems to be nearly fine still. I don't have a PH test kit...so i just eyeball it and sparingly give nutes

I posted pics of before and after under 420 "my gallery"