Thats prolly Ph being off (to high) locking up some nutes, regarding to the HPS heat issue u need to to something about that...

Build a screen:
- my sugestion get 2 pieces of pine wood or any other cheap wood u can get, about 1 feet high each and as wide as ur area, drill the set up one on top and the other piece at the bottom of your area on the inside fix them to the walls (on the inside of the door)
- drill one hole in each pieace so u can get the fans (or the duckting) on those holes
- get some velcro and stapple a few pieaces on the bottom and on the top pieces of wood
- get a black piece of plastic (i used 10 litres bin bags to do mine) staple some velcro on it to, u can later place mylar on the inside of that plastic

this way u when ur on your dark period even with the door open or semi-open u prevent light to get in the growroom u also prevent light leaking out and u can also run the fans without having to drill holes in your door, this may sound tricky and expensive but bealive me its not...

and if you are using ocean forest soil u wont need to feed ur plants for the next 3-4 weeks but make sure u get a ph test kit so u can allways know whats your water ph....Peace and Pot