Yellowing Plant, please help

I have a White Widow underneath a 400 w hps in veg right now. It is in ocean forest soil and I am not currently using any nutrients. I tried using the general organics line of nutrients but i seem to burn the plant every time. My question is why is my plant yellowing like this? The average temp is about 85 to 90 and I know this is not good. The problem is though I cannot really ventilate the room. I thought about using CO2 so the high temps wouldnt be too much a big deal. If anyone has any other ideas on how to cool a room with no ventilation please let me know. The average humidity is round 30%. Can someone please tell me why my plant is yeallowing like this and what I can do to fix it?

it does show nutrient burn on the lower leaves, but overall not bad, in fact your plant looks pretty good but lacking in nitrogen. can you get a good water soluble fertilizer like Jacks? there are several good ones available. if you can, mix the fertilizer at half strength and begin a nute program.

as far as cooling the room, can you get a portable room ac? GL

Thanks, I'll have to look into the portable air conditioners. As far as nutrients go, how often should I feed the plant nurtients? The General Organics nutrient line has 6 different nutes I think and it said to mix it with a gallon of water, should I mix all six of the nutes with one gallon or should i mix it with 6 gallons of water?

there is no reason to use 6 nuts. you should use there grow, maybe cal/mag as well. get a ppm meter and start checking your nuts. im using gen now to but there still small, first time using promix and im finding they are a bit sensitive too. never had a problem with gen when using you run of the mill organic dirt mix.
that being said i am having the same issue with the same strain, ill be following this to see how you fixed. dealing with it for 2weeks cal mag dont seem to help im upping my ppm's to around 600 but your plants are much bigger so should be able to handle a bit more

IMO- looks like a nute issue-- too much "N" and too low on the P-K and magnesium...

Are you following a feeding schedule/mixing chart- or just the bottle? The bottle is never a good idea...
You need a good CalMag that won't burn-- some have "N" in them- so read the label...
What is the pH of your water & nute solution?

Look into Recipe For Success by Technaflora. About 40 bucks at amazon and everything you'll need to get associated with nutes firsthand

Now you have burnt them trying to correct the yellowing which was caused by incorrect ph not lack of food. Flush and get the ph to 6.5. Also is the pot big enough?