So you had that plant grow to that size in that pot for 30 days with no nutes? I'd say if that was the case and you got a lot of roots sticking out the bottom holes of the pot that your plant needed nutes and wasn't overfertilized, if hellraizer30 say overferted then maybe but i don't see how and with all that perlite it got to weaken the available nutes again making it even more nute deficient. Hmm, if i had leaves in that scenario i'd fertilize too as you say you have just done, if the problem dosen't stop or show signs of slowing then maybe it is nute burn. Guess we'll see what happens with the added ferts now.