Need Help with Height of light and Humidity

Hi I was wondering if you guys could help me out. I have a 400 watt HPS on 3 plants that are in there 2nd week of 12/12. The Area the plants take up is about 5'X3'. I have the light about 16 inches from the center plant so that means even further for the plant on the left and right. Is that an ok height to have the light at?? The humidity right now is 30%. Ive had an issue trying to raise humidity the whole grow. I also have a 140CFM exhaust fan and a huge fan blowing air between the plants and the HPS. I noticed a little heat stress on the center plants fan leaves but not much. Should I be worried about heat stress while flowering? I know there should be low humidity during that time. Here is a pic of the room. Let me know what u guys think. Thanks again

Wind burn not heat....just based on what you said and without temps
Take the light to 12" after the leaves recover

Based on pics the leaves look like they are "praying" for mag and your ph looks slightly high..."banding" "rosetting"

I keep my plants 6-8" from the 400w hps light with a 10" fan blowing directly at the light. I run them close for a better yield. Heat stressed flowers will be extra dense but will have less resin, so are less potent. Lower humidity works fine for me, just keep them watered.

Also you can bend the branches down on your plants if some are too close to the light, they can handle being bent around just fine.

The banding could be a zinc problem.

you would have produced better buds and yield if you had lollipop and or lst'd. I wouldnt bend the plants or train them while they are in flower. only if you absolutly had too. qwizoking is right you should take his advice. If theres no light track moving that 400 i would rotate the plants on the side to get a even light penetration for the side plants.

My PH has steadily been 6.0. What do u mean by lollipop? is it too late to lollipop? I topped 2 of them and they branched out pretty good. Is there anyway i can make it better for better potency and yield? This is my second indoor grow. Do u think they will still come out pretty decent?

yeah bro your doing a good job . there looking good . and that was smart by topping . lollipoping is when you remove all the bottom branches, bouta 3rd of the plant. lights cant really penenatrate that deep down the canopy let alone a 400 watt . by doing so your plant will save that energy that would have been WASTED on the fluff on the bottom and exerted to the top nugs resulting in bigger better top buds

Thanks dude. Do u think I should still lollipop or just let it go now?