Leave Problem (pics)

It has been 4 weeks since I started vegging these guys in some jiffy pots. Within a week I am going to plant them in a bigger pots with better soil and switch over to 400w hps but the last couple days I have been having a problem with the lower leaves dying. I have pruned off the completly dead ones but I am continuing to have problems and need to know what nutrients/salts or what I can do to fix this problem before I go all out on my grow room. Here are some pictures please let me know.

use the search function.... look up plant problems.... or diagnoses and shit......there is lots of threads that can help you (for future reference). are you giving the plants nutes? how much?

I cant switch them for another 1 week but until that time what can I do to keep them healthy? I watered them with a 1sp/gallon of epson salt mix. I am repotting and moving them to a bigger room in about a week but I dont want any serious problems before that happens... anything I can do to help their current state and help them out?

Some of my plants are the same as yours mate. the day after i put them into flower it started on the lower leafs as yours, and on the leafs further up the plant have brown spots on them.

I think i have over nutted mine, and will be lowering the amount nect time i water